Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

633 files changed, 33339 insertions, 0 deletions

diff --git a/js/src/tests/test262/language/expressions/async-generator/array-destructuring-param-strict-body.js b/js/src/tests/test262/language/expressions/async-generator/array-destructuring-param-strict-body.js
new file mode 100644
index 0000000000..f784b81fdb
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/array-destructuring-param-strict-body.js
@@ -0,0 +1,113 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/array-destructuring-param-strict-body.case
+// - src/function-forms/syntax/async-gen-func-expr.template
+/*---
+description: ArrayBindingPattern and Use Strict Directive are not allowed to coexist for the same function. (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [rest-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.4 Static Semantics: IsSimpleParameterList
+
+    BindingElement : BindingPattern
+
+    1. Return false.
+
+    14.1.2 Static Semantics: Early Errors
+
+    FunctionDeclaration : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+    FunctionDeclaration : function ( FormalParameters ) { FunctionBody }
+    FunctionExpression : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.2.1 Static Semantics: Early Errors
+
+    ArrowFunction : ArrowParameters => ConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of ConciseBody is true and
+      IsSimpleParameterList of ArrowParameters is false.
+
+    14.3.1 Static Semantics: Early Errors
+
+    MethodDefinition : PropertyName ( UniqueFormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    MethodDefinition : set PropertyName ( PropertySetParameterList ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of PropertySetParameterList is false.
+
+    14.4.1 Static Semantics: Early Errors
+
+    GeneratorMethod : * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    GeneratorDeclaration : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+    GeneratorDeclaration : function * ( FormalParameters ) { GeneratorBody }
+    GeneratorExpression : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    14.5.1 Static Semantics: Early Errors
+
+    AsyncGeneratorMethod : async * PropertyName ( UniqueFormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncGeneratorDeclaration : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorDeclaration : async function * ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorExpression : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.7.1 Static Semantics: Early Errors
+
+    AsyncMethod : async PropertyName ( UniqueFormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncFunctionDeclaration : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionDeclaration : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.8.1 Static Semantics: Early Errors
+
+    AsyncArrowFunction : CoverCallExpressionAndAsyncArrowHead => AsyncConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncConciseBody is true and
+      IsSimpleParameterList of CoverCallExpressionAndAsyncArrowHead is false.
+
+---*/
+$DONOTEVALUATE();
+
+
+0, async function*([element]) {
+  "use strict";
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/await-as-binding-identifier-escaped.js b/js/src/tests/test262/language/expressions/async-generator/await-as-binding-identifier-escaped.js
new file mode 100644
index 0000000000..2cd503c078
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/await-as-binding-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-binding-identifier-escaped.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  var \u0061wait;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/await-as-binding-identifier.js b/js/src/tests/test262/language/expressions/async-generator/await-as-binding-identifier.js
new file mode 100644
index 0000000000..fcabda660d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/await-as-binding-identifier.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-binding-identifier.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  var await;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/await-as-identifier-reference-escaped.js b/js/src/tests/test262/language/expressions/async-generator/await-as-identifier-reference-escaped.js
new file mode 100644
index 0000000000..5a0c21c9b0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/await-as-identifier-reference-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-identifier-reference-escaped.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  void \u0061wait;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/await-as-identifier-reference.js b/js/src/tests/test262/language/expressions/async-generator/await-as-identifier-reference.js
new file mode 100644
index 0000000000..6c90eb6de0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/await-as-identifier-reference.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-identifier-reference.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  void await;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/await-as-label-identifier-escaped.js b/js/src/tests/test262/language/expressions/async-generator/await-as-label-identifier-escaped.js
new file mode 100644
index 0000000000..7a02e08b63
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/await-as-label-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-label-identifier-escaped.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a label identifier. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  \u0061wait: ;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/await-as-label-identifier.js b/js/src/tests/test262/language/expressions/async-generator/await-as-label-identifier.js
new file mode 100644
index 0000000000..0c53650007
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/await-as-label-identifier.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-label-identifier.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a label identifier. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  await: ;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/browser.js b/js/src/tests/test262/language/expressions/async-generator/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/browser.js
diff --git a/js/src/tests/test262/language/expressions/async-generator/default-proto.js b/js/src/tests/test262/language/expressions/async-generator/default-proto.js
new file mode 100644
index 0000000000..0a3c32591f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/default-proto.js
@@ -0,0 +1,53 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-asyncgenerator-definitions-evaluatebody
+description: >
+  Default [[Prototype]] value derived from realm of the async generator function.
+info: |
+  Runtime Semantics: EvaluateBody
+
+  ...
+  2. Let generator be ? OrdinaryCreateFromConstructor(functionObject, "%AsyncGeneratorPrototype%", « ... »).
+  3. Perform ! AsyncGeneratorStart(generator, FunctionBody).
+  4. Return Completion { [[Type]]: return, [[Value]]: generator, [[Target]]: empty }.
+
+  OrdinaryCreateFromConstructor ( constructor, intrinsicDefaultProto [ , internalSlotsList ] )
+
+  ...
+  2. Let proto be ? GetPrototypeFromConstructor(constructor, intrinsicDefaultProto).
+  3. Return ObjectCreate(proto, internalSlotsList).
+
+  GetPrototypeFromConstructor ( constructor, intrinsicDefaultProto )
+
+  ...
+  3. Let proto be ? Get(constructor, 'prototype').
+  4. If Type(proto) is not Object, then
+    a. Let realm be ? GetFunctionRealm(constructor).
+    b. Set proto to realm's intrinsic object named intrinsicDefaultProto.
+  5. Return proto.
+features: [async-iteration, Symbol]
+---*/
+
+var fn = async function* () {};
+var AsyncGeneratorPrototype = Object.getPrototypeOf(fn.prototype);
+
+fn.prototype = undefined;
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is undefined');
+
+fn.prototype = null;
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is null');
+
+fn.prototype = false;
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is a Boolean');
+
+fn.prototype = '';
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is a String');
+
+fn.prototype = Symbol();
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is a Symbol');
+
+fn.prototype = 1;
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is a Number');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dflt-params-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/dflt-params-abrupt.js
new file mode 100644
index 0000000000..17d59b1006
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dflt-params-abrupt.js
@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-abrupt.case
+// - src/function-forms/error/async-gen-func-expr.template
+/*---
+description: Abrupt completion returned by evaluation of initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*(_ = (function() { throw new Test262Error(); }())) {
+  
+  callCount = callCount + 1;
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+assert.sameValue(callCount, 0, 'generator function body not evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dflt-params-arg-val-not-undefined.js b/js/src/tests/test262/language/expressions/async-generator/dflt-params-arg-val-not-undefined.js
new file mode 100644
index 0000000000..d31b712980
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dflt-params-arg-val-not-undefined.js
@@ -0,0 +1,66 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-arg-val-not-undefined.case
+// - src/function-forms/default/async-gen-func-expr.template
+/*---
+description: Use of initializer when argument value is not `undefined` (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    [...]
+    23. Let iteratorRecord be Record {[[Iterator]]:
+        CreateListIterator(argumentsList), [[Done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        a. Perform ? IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+---*/
+var obj = {};
+var falseCount = 0;
+var stringCount = 0;
+var nanCount = 0;
+var zeroCount = 0;
+var nullCount = 0;
+var objCount = 0;
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function*(aFalse = falseCount +=1, aString = stringCount += 1, aNaN = nanCount += 1, a0 = zeroCount += 1, aNull = nullCount += 1, aObj = objCount +=1) {
+  assert.sameValue(aFalse, false);
+  assert.sameValue(aString, '');
+  assert.sameValue(aNaN, NaN);
+  assert.sameValue(a0, 0);
+  assert.sameValue(aNull, null);
+  assert.sameValue(aObj, obj);
+  callCount = callCount + 1;
+};
+
+ref(false, '', NaN, 0, null, obj).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+assert.sameValue(falseCount, 0, 'initializer not evaluated: false');
+assert.sameValue(stringCount, 0, 'initializer not evaluated: string');
+assert.sameValue(nanCount, 0, 'initializer not evaluated: NaN');
+assert.sameValue(zeroCount, 0, 'initializer not evaluated: 0');
+assert.sameValue(nullCount, 0, 'initializer not evaluated: null');
+assert.sameValue(objCount, 0, 'initializer not evaluated: object');
diff --git a/js/src/tests/test262/language/expressions/async-generator/dflt-params-arg-val-undefined.js b/js/src/tests/test262/language/expressions/async-generator/dflt-params-arg-val-undefined.js
new file mode 100644
index 0000000000..cb336ce231
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dflt-params-arg-val-undefined.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-arg-val-undefined.case
+// - src/function-forms/default/async-gen-func-expr.template
+/*---
+description: Use of initializer when argument value is `undefined` (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    [...]
+    23. Let iteratorRecord be Record {[[Iterator]]:
+        CreateListIterator(argumentsList), [[Done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        a. Perform ? IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+---*/
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function*(fromLiteral = 23, fromExpr = 45, fromHole = 99) {
+  assert.sameValue(fromLiteral, 23);
+  assert.sameValue(fromExpr, 45);
+  assert.sameValue(fromHole, 99);
+  callCount = callCount + 1;
+};
+
+ref(undefined, void 0).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dflt-params-duplicates.js b/js/src/tests/test262/language/expressions/async-generator/dflt-params-duplicates.js
new file mode 100644
index 0000000000..f1958d74b7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dflt-params-duplicates.js
@@ -0,0 +1,42 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-duplicates.case
+// - src/function-forms/syntax/async-gen-func-expr.template
+/*---
+description: It is a Syntax Error if BoundNames of FormalParameters contains any duplicate elements. (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    14.1.2 Static Semantics: Early Errors
+
+    StrictFormalParameters : FormalParameters
+
+    - It is a Syntax Error if BoundNames of FormalParameters contains any
+      duplicate elements.
+
+    FormalParameters : FormalParameterList
+
+    - It is a Syntax Error if IsSimpleParameterList of FormalParameterList is
+      false and BoundNames of FormalParameterList contains any duplicate
+      elements.
+
+---*/
+$DONOTEVALUATE();
+
+
+0, async function*(x = 0, x) {
+  
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/dflt-params-ref-later.js b/js/src/tests/test262/language/expressions/async-generator/dflt-params-ref-later.js
new file mode 100644
index 0000000000..14c63f3d22
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dflt-params-ref-later.js
@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-ref-later.case
+// - src/function-forms/error/async-gen-func-expr.template
+/*---
+description: Referencing a parameter that occurs later in the ParameterList (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+var x = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*(x = y, y) {
+  
+  callCount = callCount + 1;
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+assert.sameValue(callCount, 0, 'generator function body not evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dflt-params-ref-prior.js b/js/src/tests/test262/language/expressions/async-generator/dflt-params-ref-prior.js
new file mode 100644
index 0000000000..94a5a0fe46
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dflt-params-ref-prior.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-ref-prior.case
+// - src/function-forms/default/async-gen-func-expr.template
+/*---
+description: Referencing a parameter that occurs earlier in the ParameterList (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+var x = 0;
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function*(x, y = x, z = y) {
+  assert.sameValue(x, 3, 'first argument value');
+  assert.sameValue(y, 3, 'second argument value');
+  assert.sameValue(z, 3, 'third argument value');
+  callCount = callCount + 1;
+};
+
+ref(3).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dflt-params-ref-self.js b/js/src/tests/test262/language/expressions/async-generator/dflt-params-ref-self.js
new file mode 100644
index 0000000000..cb5edc0a37
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dflt-params-ref-self.js
@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-ref-self.case
+// - src/function-forms/error/async-gen-func-expr.template
+/*---
+description: Referencing a parameter from within its own initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+var x = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*(x = x) {
+  
+  callCount = callCount + 1;
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+assert.sameValue(callCount, 0, 'generator function body not evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dflt-params-rest.js b/js/src/tests/test262/language/expressions/async-generator/dflt-params-rest.js
new file mode 100644
index 0000000000..ec30e10335
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dflt-params-rest.js
@@ -0,0 +1,46 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-rest.case
+// - src/function-forms/syntax/async-gen-func-expr.template
+/*---
+description: RestParameter does not support an initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    14.1 Function Definitions
+
+    Syntax
+
+    FunctionRestParameter[Yield] :
+
+      BindingRestElement[?Yield]
+
+    13.3.3 Destructuring Binding Patterns
+
+    Syntax
+
+    BindingRestElement[Yield] :
+
+      ...BindingIdentifier[?Yield]
+      ...BindingPattern[?Yield]
+
+---*/
+$DONOTEVALUATE();
+
+
+0, async function*(...x = []) {
+  
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/dflt-params-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dflt-params-trailing-comma.js
new file mode 100644
index 0000000000..9ac29e9f5d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dflt-params-trailing-comma.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-trailing-comma.case
+// - src/function-forms/default/async-gen-func-expr.template
+/*---
+description: A trailing comma should not increase the respective length, using default parameters (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] : FormalParameterList[?Yield, ?Await] ,
+---*/
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function*(a, b = 39,) {
+  assert.sameValue(a, 42);
+  assert.sameValue(b, 39);
+  callCount = callCount + 1;
+};
+
+ref(42, undefined, 1).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+assert.sameValue(ref.length, 1, 'length is properly set');
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-close.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-close.js
new file mode 100644
index 0000000000..1dcc3e2656
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-close.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-close.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Iterator is closed when not exhausted by pattern evaluation (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: false };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([x]) {
+  assert.sameValue(doneCallCount, 1);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-get-err-array-prototype.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-get-err-array-prototype.js
new file mode 100644
index 0000000000..5cb585bbbf
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-get-err-array-prototype.js
@@ -0,0 +1,47 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-get-err-array-prototype.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iteratorRecord be ? GetIterator(value).
+
+    GetIterator ( obj [ , hint [ , method ] ] )
+
+    [...]
+    4. Let iterator be ? Call(method, obj).
+
+    Call ( F, V [ , argumentsList ] )
+
+    [...]
+    2. If IsCallable(F) is false, throw a TypeError exception.
+
+---*/
+delete Array.prototype[Symbol.iterator];
+
+
+var f;
+f = async function*([x, y, z]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([1, 2, 3]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-get-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-get-err.js
new file mode 100644
index 0000000000..67b9f20367
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-get-err.js
@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-get-err.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iterator be GetIterator(value).
+    2. ReturnIfAbrupt(iterator).
+
+---*/
+var iter = {};
+iter[Symbol.iterator] = function() {
+  throw new Test262Error();
+};
+
+
+var f;
+f = async function*([x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-no-close.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-no-close.js
new file mode 100644
index 0000000000..44864fc314
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-init-iter-no-close.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-no-close.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Iterator is not closed when exhausted by pattern evaluation (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: true };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([x]) {
+  assert.sameValue(doneCallCount, 0);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-name-iter-val.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-name-iter-val.js
new file mode 100644
index 0000000000..48ed914025
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-name-iter-val.js
@@ -0,0 +1,53 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-name-iter-val.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding with normal value iteration (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x, y, z]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elem-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elem-init.js
new file mode 100644
index 0000000000..2d0e070008
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elem-init.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([[x, y, z] = [4, 5, 6]]) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elem-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elem-iter.js
new file mode 100644
index 0000000000..266dc51dec
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elem-iter.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-iter.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([[x, y, z] = [4, 5, 6]]) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, 8);
+  assert.sameValue(z, 9);
+  callCount = callCount + 1;
+};
+
+f([[7, 8, 9]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elision-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elision-init.js
new file mode 100644
index 0000000000..a49d427ea2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elision-init.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([[,] = g()]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elision-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elision-iter.js
new file mode 100644
index 0000000000..cc70c99292
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-elision-iter.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-iter.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var callCount = 0;
+function* g() {
+  callCount += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([[,] = g()]) {
+  assert.sameValue(callCount, 0);
+  callCount = callCount + 1;
+};
+
+f([[]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-empty-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-empty-init.js
new file mode 100644
index 0000000000..a37748b75b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-empty-init.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var initCount = 0;
+var iterCount = 0;
+var iter = function*() { iterCount += 1; }();
+
+
+var callCount = 0;
+var f;
+f = async function*([[] = function() { initCount += 1; return iter; }()]) {
+  assert.sameValue(initCount, 1);
+  assert.sameValue(iterCount, 0);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-empty-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-empty-iter.js
new file mode 100644
index 0000000000..e5a2e43d6f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-empty-iter.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-iter.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*([[] = function() { initCount += 1; }()]) {
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f([[23]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-rest-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-rest-init.js
new file mode 100644
index 0000000000..19f0aea85c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-rest-init.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([[...x] = values]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-rest-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-rest-iter.js
new file mode 100644
index 0000000000..83f4a32015
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-rest-iter.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-iter.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*([[...x] = function() { initCount += 1; }()]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f([values]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-val-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-val-null.js
new file mode 100644
index 0000000000..2b1f1614e3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-ary-val-null.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-val-null.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Nested array destructuring with a null value (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iterator be GetIterator(value).
+    2. ReturnIfAbrupt(iterator).
+---*/
+
+
+var f;
+f = async function*([[x]]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([null]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-exhausted.js
new file mode 100644
index 0000000000..cc796ac033
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-exhausted.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Destructuring initializer with an exhausted iterator (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23]) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-arrow.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..29069b8512
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-arrow.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding does assign name to arrow functions (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([arrow = () => {}]) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-class.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-class.js
new file mode 100644
index 0000000000..ad46341436
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-class.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-class.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([cls = class {}, xCls = class X {}, xCls2 = class { static name() {} }]) {
+  assert.sameValue(cls.name, 'cls');
+  assert.notSameValue(xCls.name, 'xCls');
+  assert.notSameValue(xCls2.name, 'xCls2');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-cover.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..976a55fd0d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-cover.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-cover.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding does assign name to "anonymous" functions "through" cover grammar (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([cover = (function () {}), xCover = (0, function() {})]) {
+  assert.sameValue(cover.name, 'cover');
+  assert.notSameValue(xCover.name, 'xCover');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-fn.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..c3f876d535
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-fn.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([fn = function () {}, xFn = function x() {}]) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-gen.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..082991adf5
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-gen.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([gen = function* () {}, xGen = function* x() {}]) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-hole.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-hole.js
new file mode 100644
index 0000000000..5ce49a08c2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-hole.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-hole.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Destructuring initializer with a "hole" (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    SingleNameBinding : BindingIdentifier Initializeropt
+    [...] 6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v). 8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23]) {
+  assert.sameValue(x, 23);
+  // another statement
+  callCount = callCount + 1;
+};
+
+f([,]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-skipped.js
new file mode 100644
index 0000000000..9363556383
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-skipped.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*([w = counter(), x = counter(), y = counter(), z = counter()]) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f([null, 0, false, '']).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-throws.js
new file mode 100644
index 0000000000..4e1e78a6d1
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-throws.js
@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Destructuring initializer returns an abrupt completion (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+
+
+var f;
+f = async function*([x = (function() { throw new Test262Error(); })()]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f([undefined]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-undef.js
new file mode 100644
index 0000000000..f5a99edcba
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-undef.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-undef.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Destructuring initializer with an undefined value (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23]) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f([undefined]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-unresolvable.js
new file mode 100644
index 0000000000..75a446295c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-init-unresolvable.js
@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f;
+f = async function*([ x = unresolvableReference ]) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f([]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-complete.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-complete.js
new file mode 100644
index 0000000000..26a57379c7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-complete.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-complete.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding when value iteration completes (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x]) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-done.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-done.js
new file mode 100644
index 0000000000..2ea2da95af
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-done.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-done.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([_, x]) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-step-err.js
new file mode 100644
index 0000000000..26a2d14faa
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-step-err.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-step-err.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+
+---*/
+var g = {};
+g[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      throw new Test262Error();
+    }
+  };
+};
+
+
+var f;
+f = async function*([x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(g);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-val-array-prototype.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-val-array-prototype.js
new file mode 100644
index 0000000000..73d25c1705
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-val-array-prototype.js
@@ -0,0 +1,63 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val-array-prototype.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Array destructuring uses overriden Array.prototype[Symbol.iterator] (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializer_opt
+
+    1. Let bindingId be StringValue of BindingIdentifier.
+    2. Let lhs be ? ResolveBinding(bindingId, environment).
+    3. If iteratorRecord.[[Done]] is false, then
+        a. Let next be IteratorStep(iteratorRecord).
+        b. If next is an abrupt completion, set iteratorRecord.[[Done]] to true.
+        c. ReturnIfAbrupt(next).
+        d. If next is false, set iteratorRecord.[[Done]] to true.
+        e. Else,
+            i. Let v be IteratorValue(next).
+            ii. If v is an abrupt completion, set iteratorRecord.[[Done]] to true.
+            iii. ReturnIfAbrupt(v).
+    [...]
+    7. Return InitializeReferencedBinding(lhs, v).
+
+---*/
+Array.prototype[Symbol.iterator] = function* () {
+    if (this.length > 0) {
+        yield this[0];
+    }
+    if (this.length > 1) {
+        yield this[1];
+    }
+    if (this.length > 2) {
+        yield 42;
+    }
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([x, y, z]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 42);
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-val-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-val-err.js
new file mode 100644
index 0000000000..b02564fff1
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-val-err.js
@@ -0,0 +1,59 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val-err.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set iteratorRecord.[[done]] to
+              true.
+          iii. ReturnIfAbrupt(v).
+
+---*/
+var poisonedValue = Object.defineProperty({}, 'value', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+var g = {};
+g[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return poisonedValue;
+    }
+  };
+};
+
+
+var f;
+f = async function*([x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(g);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-val.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-val.js
new file mode 100644
index 0000000000..6697962b06
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-id-iter-val.js
@@ -0,0 +1,53 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x, y, z]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-id-init.js
new file mode 100644
index 0000000000..ea0eef697a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-id-init.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ x, y, z } = { x: 44, y: 55, z: 66 }]) {
+  assert.sameValue(x, 44);
+  assert.sameValue(y, 55);
+  assert.sameValue(z, 66);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-id.js
new file mode 100644
index 0000000000..7ff4b3d066
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-id.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ x, y, z } = { x: 44, y: 55, z: 66 }]) {
+  assert.sameValue(x, 11);
+  assert.sameValue(y, 22);
+  assert.sameValue(z, 33);
+  callCount = callCount + 1;
+};
+
+f([{ x: 11, y: 22, z: 33 }]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-prop-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-prop-id-init.js
new file mode 100644
index 0000000000..1e4325e2db
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-prop-id-init.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }]) {
+  assert.sameValue(v, 444);
+  assert.sameValue(x, 555);
+  assert.sameValue(z, 666);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-prop-id.js
new file mode 100644
index 0000000000..e2010ffac4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-prop-id.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }]) {
+  assert.sameValue(v, 777);
+  assert.sameValue(x, 888);
+  assert.sameValue(z, 999);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f([{ u: 777, w: 888, y: 999 }]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-val-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-val-null.js
new file mode 100644
index 0000000000..9d1a82fc2a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-val-null.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-val-null.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Nested object destructuring with a null value (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ObjectBindingPattern
+
+    1. Let valid be RequireObjectCoercible(value).
+    2. ReturnIfAbrupt(valid).
+---*/
+
+
+var f;
+f = async function*([{ x }]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([null]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-val-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-val-undef.js
new file mode 100644
index 0000000000..d580f6a081
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elem-obj-val-undef.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-val-undef.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Nested object destructuring with a value of `undefined` (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ObjectBindingPattern
+
+    1. Let valid be RequireObjectCoercible(value).
+    2. ReturnIfAbrupt(valid).
+---*/
+
+
+var f;
+f = async function*([{ x }]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elision-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elision-exhausted.js
new file mode 100644
index 0000000000..cd6b7abcab
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elision-exhausted.js
@@ -0,0 +1,50 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Elision accepts exhausted iterator (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+    2. Return NormalCompletion(empty).
+
+---*/
+var iter = function*() {}();
+iter.next();
+
+
+var callCount = 0;
+var f;
+f = async function*([,]) {
+  
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elision-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elision-step-err.js
new file mode 100644
index 0000000000..c474cf744f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elision-step-err.js
@@ -0,0 +1,55 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision-step-err.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Elision advances iterator and forwards abrupt completions (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+
+---*/
+var following = 0;
+var iter =function* () {
+  throw new Test262Error();
+  following += 1;
+}();
+
+
+var f;
+f = async function*([,]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+iter.next();
+assert.sameValue(following, 0, 'Iterator was properly closed.');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elision.js
new file mode 100644
index 0000000000..3c4cb4a8c0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-elision.js
@@ -0,0 +1,59 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Elision advances iterator (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([,]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f(g()).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-empty.js
new file mode 100644
index 0000000000..023be481b4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-empty.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: No iteration occurs for an "empty" array binding pattern (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function*([]) {
+  assert.sameValue(iterations, 0);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-elem.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-elem.js
new file mode 100644
index 0000000000..e13b0cfc47
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-elem.js
@@ -0,0 +1,66 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elem.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing an array BindingElementList pattern (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...[x, y, z]]) {
+  assert.sameValue(x, 3);
+  assert.sameValue(y, 4);
+  assert.sameValue(z, 5);
+  callCount = callCount + 1;
+};
+
+f([3, 4, 5]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-elision.js
new file mode 100644
index 0000000000..294b44e669
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-elision.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elision.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing an elision (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([...[,]]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 1);
+  callCount = callCount + 1;
+};
+
+f(g()).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-empty.js
new file mode 100644
index 0000000000..63ef39c650
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-empty.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-empty.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing an "empty" array pattern (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function*([...[]]) {
+  assert.sameValue(iterations, 1);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-rest.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-rest.js
new file mode 100644
index 0000000000..9176882e76
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-ary-rest.js
@@ -0,0 +1,51 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-rest.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing a rest element (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([...[...x]]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+
+  callCount = callCount + 1;
+};
+
+f(values).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-direct.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-direct.js
new file mode 100644
index 0000000000..7bcc2d0d53
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-direct.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-direct.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Lone rest element (direct binding) (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+includes: [compareArray.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingIdentifier
+
+    [...]
+    2. Let A be ! ArrayCreate(0).
+    3. Let n be 0.
+    4. Repeat,
+        [...]
+        f. Perform ! CreateDataPropertyOrThrow(A, ! ToString(n), nextValue).
+        g. Set n to n + 1.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...x]) {
+  assert(Array.isArray(x));
+  assert.compareArray(x, [1]);
+  callCount = callCount + 1;
+};
+
+f([1]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-elision-next-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-elision-next-err.js
new file mode 100644
index 0000000000..9a11688bb7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-elision-next-err.js
@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-elision-next-err.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Rest element following elision elements (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    ArrayBindingPattern : [ Elisionopt BindingRestElement ]
+    1. If Elision is present, then
+       a. Let status be the result of performing
+          IteratorDestructuringAssignmentEvaluation of Elision with
+          iteratorRecord as the argument.
+       b. ReturnIfAbrupt(status).
+    2. Return the result of performing IteratorBindingInitialization for
+       BindingRestElement with iteratorRecord and environment as arguments.
+
+---*/
+var iter = (function*() { throw new Test262Error(); })();
+
+
+var f;
+f = async function*([, ...x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-elision.js
new file mode 100644
index 0000000000..9849f08ca2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-elision.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-elision.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element following elision elements (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    ArrayBindingPattern : [ Elisionopt BindingRestElement ]
+    1. If Elision is present, then
+       a. Let status be the result of performing
+          IteratorDestructuringAssignmentEvaluation of Elision with
+          iteratorRecord as the argument.
+       b. ReturnIfAbrupt(status).
+    2. Return the result of performing IteratorBindingInitialization for
+       BindingRestElement with iteratorRecord and environment as arguments.
+---*/
+var values = [1, 2, 3, 4, 5];
+
+
+var callCount = 0;
+var f;
+f = async function*([ , , ...x]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 3);
+  assert.sameValue(x[1], 4);
+  assert.sameValue(x[2], 5);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f(values).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-exhausted.js
new file mode 100644
index 0000000000..0f5e4b5117
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-exhausted.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: RestElement applied to an exhausted iterator (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. If environment is undefined, return PutValue(lhs, A).
+          ii. Return InitializeReferencedBinding(lhs, A).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([, , ...x]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 0);
+  callCount = callCount + 1;
+};
+
+f([1, 2]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-iter-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-iter-step-err.js
new file mode 100644
index 0000000000..2045ded696
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-iter-step-err.js
@@ -0,0 +1,52 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-iter-step-err.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       a. If iteratorRecord.[[done]] is false,
+          i. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+          ii. If next is an abrupt completion, set iteratorRecord.[[done]] to
+              true.
+          iii. ReturnIfAbrupt(next).
+
+---*/
+var first = 0;
+var second = 0;
+var iter = function*() {
+  first += 1;
+  throw new Test262Error();
+  second += 1;
+}();
+
+
+var f;
+f = async function*([...x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+iter.next();
+assert.sameValue(first, 1);
+assert.sameValue(second, 0, 'Iterator is closed following abrupt completion.');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-iter-val-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-iter-val-err.js
new file mode 100644
index 0000000000..8a82af9983
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id-iter-val-err.js
@@ -0,0 +1,54 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-iter-val-err.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       c. Let nextValue be IteratorValue(next).
+       d. If nextValue is an abrupt completion, set iteratorRecord.[[done]] to
+          true.
+       e. ReturnIfAbrupt(nextValue).
+
+---*/
+var poisonedValue = Object.defineProperty({}, 'value', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return poisonedValue;
+    }
+  };
+};
+
+
+var f;
+f = async function*([...x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id.js
new file mode 100644
index 0000000000..4f05e3a47c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-id.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Lone rest element (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    [...] 3. Let A be ArrayCreate(0). [...] 5. Repeat
+       [...]
+       f. Let status be CreateDataProperty(A, ToString (n), nextValue).
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([...x]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f(values).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-init-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-init-ary.js
new file mode 100644
index 0000000000..7a760e18fe
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-init-ary.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-ary.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element (nested array pattern) does not support initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...[ x ] = []]) {
+  
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-init-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-init-id.js
new file mode 100644
index 0000000000..98ed74335e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-init-id.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element (identifier) does not support initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...x = []]) {
+  
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-init-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-init-obj.js
new file mode 100644
index 0000000000..f94136a18a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-init-obj.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-obj.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element (nested object pattern) does not support initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ x } = []]) {
+  
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-not-final-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-not-final-ary.js
new file mode 100644
index 0000000000..d72f4adf31
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-not-final-ary.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-ary.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element (array binding pattern) may not be followed by any element (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...[x], y]) {
+  
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-not-final-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-not-final-id.js
new file mode 100644
index 0000000000..095c4664ac
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-not-final-id.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element (identifier) may not be followed by any element (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...x, y]) {
+  
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-not-final-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-not-final-obj.js
new file mode 100644
index 0000000000..0841df9c51
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-not-final-obj.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-obj.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element (object binding pattern) may not be followed by any element (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ x }, y]) {
+  
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-obj-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-obj-id.js
new file mode 100644
index 0000000000..c93cf6858f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-obj-id.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing an object binding pattern (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ length }]) {
+  assert.sameValue(length, 3);
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-obj-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-obj-prop-id.js
new file mode 100644
index 0000000000..a7d413e7ce
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/ary-ptrn-rest-obj-prop-id.js
@@ -0,0 +1,51 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing an object binding pattern (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+let length = "outer";
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ 0: v, 1: w, 2: x, 3: y, length: z }]) {
+  assert.sameValue(v, 7);
+  assert.sameValue(w, 8);
+  assert.sameValue(x, 9);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, 3);
+
+  assert.sameValue(length, "outer", "the length prop is not set as a binding name");
+  callCount = callCount + 1;
+};
+
+f([7, 8, 9]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/browser.js b/js/src/tests/test262/language/expressions/async-generator/dstr/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/browser.js
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-close.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-close.js
new file mode 100644
index 0000000000..2910c7d0ac
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-close.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-close.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Iterator is closed when not exhausted by pattern evaluation (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: false };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([x] = iter) {
+  assert.sameValue(doneCallCount, 1);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-get-err-array-prototype.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-get-err-array-prototype.js
new file mode 100644
index 0000000000..26002b049d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-get-err-array-prototype.js
@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-get-err-array-prototype.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iteratorRecord be ? GetIterator(value).
+
+    GetIterator ( obj [ , hint [ , method ] ] )
+
+    [...]
+    4. Let iterator be ? Call(method, obj).
+
+    Call ( F, V [ , argumentsList ] )
+
+    [...]
+    2. If IsCallable(F) is false, throw a TypeError exception.
+
+---*/
+delete Array.prototype[Symbol.iterator];
+
+
+var f = async function*([x, y, z] = [1, 2, 3]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-get-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-get-err.js
new file mode 100644
index 0000000000..7417c77482
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-get-err.js
@@ -0,0 +1,40 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-get-err.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iterator be GetIterator(value).
+    2. ReturnIfAbrupt(iterator).
+
+---*/
+var iter = {};
+iter[Symbol.iterator] = function() {
+  throw new Test262Error();
+};
+
+
+var f = async function*([x] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-no-close.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-no-close.js
new file mode 100644
index 0000000000..833b9ce498
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-init-iter-no-close.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-no-close.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Iterator is not closed when exhausted by pattern evaluation (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: true };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([x] = iter) {
+  assert.sameValue(doneCallCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-name-iter-val.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-name-iter-val.js
new file mode 100644
index 0000000000..a3fb0f3f8d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-name-iter-val.js
@@ -0,0 +1,53 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-name-iter-val.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding with normal value iteration (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x, y, z] = [1, 2, 3]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-init.js
new file mode 100644
index 0000000000..9fbd8e825d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-init.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([[x, y, z] = [4, 5, 6]] = []) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-iter.js
new file mode 100644
index 0000000000..c87c1468e7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-iter.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-iter.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([[x, y, z] = [4, 5, 6]] = [[7, 8, 9]]) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, 8);
+  assert.sameValue(z, 9);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-init.js
new file mode 100644
index 0000000000..e054192528
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-init.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([[,] = g()] = []) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-iter.js
new file mode 100644
index 0000000000..b4f6260d6b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-iter.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-iter.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var callCount = 0;
+function* g() {
+  callCount += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([[,] = g()] = [[]]) {
+  assert.sameValue(callCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-init.js
new file mode 100644
index 0000000000..b7975f6bb1
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-init.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var initCount = 0;
+var iterCount = 0;
+var iter = function*() { iterCount += 1; }();
+
+
+var callCount = 0;
+var f;
+f = async function*([[] = function() { initCount += 1; return iter; }()] = []) {
+  assert.sameValue(initCount, 1);
+  assert.sameValue(iterCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-iter.js
new file mode 100644
index 0000000000..0a81ca4b2b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-iter.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-iter.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*([[] = function() { initCount += 1; }()] = [[23]]) {
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-init.js
new file mode 100644
index 0000000000..249d5d653b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-init.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([[...x] = values] = []) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-iter.js
new file mode 100644
index 0000000000..4830799cde
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-iter.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-iter.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*([[...x] = function() { initCount += 1; }()] = [values]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-val-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-val-null.js
new file mode 100644
index 0000000000..352174e9de
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-ary-val-null.js
@@ -0,0 +1,47 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-val-null.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Nested array destructuring with a null value (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iterator be GetIterator(value).
+    2. ReturnIfAbrupt(iterator).
+---*/
+
+
+var f = async function*([[x]] = [null]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-exhausted.js
new file mode 100644
index 0000000000..f31c183bc3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-exhausted.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer with an exhausted iterator (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23] = []) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-arrow.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..2f076685d6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-arrow.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding does assign name to arrow functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([arrow = () => {}] = []) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-class.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-class.js
new file mode 100644
index 0000000000..2dabdf4fdd
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-class.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-class.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([cls = class {}, xCls = class X {}, xCls2 = class { static name() {} }] = []) {
+  assert.sameValue(cls.name, 'cls');
+  assert.notSameValue(xCls.name, 'xCls');
+  assert.notSameValue(xCls2.name, 'xCls2');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-cover.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..9f18d946c0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-cover.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-cover.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding does assign name to "anonymous" functions "through" cover grammar (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([cover = (function () {}), xCover = (0, function() {})] = []) {
+  assert.sameValue(cover.name, 'cover');
+  assert.notSameValue(xCover.name, 'xCover');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-fn.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..e4a6dcf9f5
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-fn.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([fn = function () {}, xFn = function x() {}] = []) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-gen.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..39bae4bba0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-gen.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([gen = function* () {}, xGen = function* x() {}] = []) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-hole.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-hole.js
new file mode 100644
index 0000000000..5bfaec83aa
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-hole.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-hole.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer with a "hole" (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    SingleNameBinding : BindingIdentifier Initializeropt
+    [...] 6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v). 8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23] = [,]) {
+  assert.sameValue(x, 23);
+  // another statement
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-skipped.js
new file mode 100644
index 0000000000..b59d4d5ba8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-skipped.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*([w = counter(), x = counter(), y = counter(), z = counter()] = [null, 0, false, '']) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-throws.js
new file mode 100644
index 0000000000..5beda66084
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-throws.js
@@ -0,0 +1,38 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer returns an abrupt completion (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+
+
+var f = async function*([x = (function() { throw new Test262Error(); })()] = [undefined]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-undef.js
new file mode 100644
index 0000000000..e96638c874
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-undef.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-undef.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer with an undefined value (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23] = [undefined]) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-unresolvable.js
new file mode 100644
index 0000000000..fd29d3b01b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-init-unresolvable.js
@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f = async function*([ x = unresolvableReference ] = []) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-complete.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-complete.js
new file mode 100644
index 0000000000..ea8476aff7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-complete.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-complete.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding when value iteration completes (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x] = []) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-done.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-done.js
new file mode 100644
index 0000000000..0395e46437
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-done.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-done.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([_, x] = []) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-step-err.js
new file mode 100644
index 0000000000..917f389418
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-step-err.js
@@ -0,0 +1,47 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-step-err.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+
+---*/
+var g = {};
+g[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      throw new Test262Error();
+    }
+  };
+};
+
+
+var f = async function*([x] = g) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val-array-prototype.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val-array-prototype.js
new file mode 100644
index 0000000000..c108a49d6a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val-array-prototype.js
@@ -0,0 +1,63 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val-array-prototype.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Array destructuring uses overriden Array.prototype[Symbol.iterator] (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializer_opt
+
+    1. Let bindingId be StringValue of BindingIdentifier.
+    2. Let lhs be ? ResolveBinding(bindingId, environment).
+    3. If iteratorRecord.[[Done]] is false, then
+        a. Let next be IteratorStep(iteratorRecord).
+        b. If next is an abrupt completion, set iteratorRecord.[[Done]] to true.
+        c. ReturnIfAbrupt(next).
+        d. If next is false, set iteratorRecord.[[Done]] to true.
+        e. Else,
+            i. Let v be IteratorValue(next).
+            ii. If v is an abrupt completion, set iteratorRecord.[[Done]] to true.
+            iii. ReturnIfAbrupt(v).
+    [...]
+    7. Return InitializeReferencedBinding(lhs, v).
+
+---*/
+Array.prototype[Symbol.iterator] = function* () {
+    if (this.length > 0) {
+        yield this[0];
+    }
+    if (this.length > 1) {
+        yield this[1];
+    }
+    if (this.length > 2) {
+        yield 42;
+    }
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([x, y, z] = [1, 2, 3]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 42);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val-err.js
new file mode 100644
index 0000000000..cf7f43d642
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val-err.js
@@ -0,0 +1,58 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val-err.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set iteratorRecord.[[done]] to
+              true.
+          iii. ReturnIfAbrupt(v).
+
+---*/
+var poisonedValue = Object.defineProperty({}, 'value', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+var g = {};
+g[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return poisonedValue;
+    }
+  };
+};
+
+
+var f = async function*([x] = g) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val.js
new file mode 100644
index 0000000000..7547df9678
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val.js
@@ -0,0 +1,53 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x, y, z] = [1, 2, 3]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-id-init.js
new file mode 100644
index 0000000000..2a7e7c918c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-id-init.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ x, y, z } = { x: 44, y: 55, z: 66 }] = []) {
+  assert.sameValue(x, 44);
+  assert.sameValue(y, 55);
+  assert.sameValue(z, 66);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-id.js
new file mode 100644
index 0000000000..9d701d0cb9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-id.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ x, y, z } = { x: 44, y: 55, z: 66 }] = [{ x: 11, y: 22, z: 33 }]) {
+  assert.sameValue(x, 11);
+  assert.sameValue(y, 22);
+  assert.sameValue(z, 33);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id-init.js
new file mode 100644
index 0000000000..39aaac977f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id-init.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }] = []) {
+  assert.sameValue(v, 444);
+  assert.sameValue(x, 555);
+  assert.sameValue(z, 666);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id.js
new file mode 100644
index 0000000000..8b50023295
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }] = [{ u: 777, w: 888, y: 999 }]) {
+  assert.sameValue(v, 777);
+  assert.sameValue(x, 888);
+  assert.sameValue(z, 999);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-val-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-val-null.js
new file mode 100644
index 0000000000..d92839c0af
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-val-null.js
@@ -0,0 +1,47 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-val-null.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Nested object destructuring with a null value (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ObjectBindingPattern
+
+    1. Let valid be RequireObjectCoercible(value).
+    2. ReturnIfAbrupt(valid).
+---*/
+
+
+var f = async function*([{ x }] = [null]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-val-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-val-undef.js
new file mode 100644
index 0000000000..23f9e50f42
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elem-obj-val-undef.js
@@ -0,0 +1,47 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-val-undef.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Nested object destructuring with a value of `undefined` (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ObjectBindingPattern
+
+    1. Let valid be RequireObjectCoercible(value).
+    2. ReturnIfAbrupt(valid).
+---*/
+
+
+var f = async function*([{ x }] = []) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elision-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elision-exhausted.js
new file mode 100644
index 0000000000..23d7f11e35
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elision-exhausted.js
@@ -0,0 +1,50 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Elision accepts exhausted iterator (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+    2. Return NormalCompletion(empty).
+
+---*/
+var iter = function*() {}();
+iter.next();
+
+
+var callCount = 0;
+var f;
+f = async function*([,] = iter) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elision-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elision-step-err.js
new file mode 100644
index 0000000000..91af3f4a52
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elision-step-err.js
@@ -0,0 +1,54 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision-step-err.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Elision advances iterator and forwards abrupt completions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+
+---*/
+var following = 0;
+var iter =function* () {
+  throw new Test262Error();
+  following += 1;
+}();
+
+
+var f = async function*([,] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+iter.next();
+assert.sameValue(following, 0, 'Iterator was properly closed.');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elision.js
new file mode 100644
index 0000000000..e3030c6fff
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-elision.js
@@ -0,0 +1,59 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Elision advances iterator (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([,] = g()) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-empty.js
new file mode 100644
index 0000000000..c13d5103a5
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-empty.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: No iteration occurs for an "empty" array binding pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function*([] = iter) {
+  assert.sameValue(iterations, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-elem.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-elem.js
new file mode 100644
index 0000000000..fe32d9fec0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-elem.js
@@ -0,0 +1,66 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elem.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing an array BindingElementList pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...[x, y, z]] = [3, 4, 5]) {
+  assert.sameValue(x, 3);
+  assert.sameValue(y, 4);
+  assert.sameValue(z, 5);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-elision.js
new file mode 100644
index 0000000000..c8fc278a84
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-elision.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elision.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing an elision (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([...[,]] = g()) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 1);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-empty.js
new file mode 100644
index 0000000000..fb0cd86521
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-empty.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-empty.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing an "empty" array pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function*([...[]] = iter) {
+  assert.sameValue(iterations, 1);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-rest.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-rest.js
new file mode 100644
index 0000000000..0d5caadf49
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-ary-rest.js
@@ -0,0 +1,51 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-rest.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing a rest element (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([...[...x]] = values) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-direct.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-direct.js
new file mode 100644
index 0000000000..5eae1b6f9f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-direct.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-direct.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Lone rest element (direct binding) (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+includes: [compareArray.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingIdentifier
+
+    [...]
+    2. Let A be ! ArrayCreate(0).
+    3. Let n be 0.
+    4. Repeat,
+        [...]
+        f. Perform ! CreateDataPropertyOrThrow(A, ! ToString(n), nextValue).
+        g. Set n to n + 1.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...x] = [1]) {
+  assert(Array.isArray(x));
+  assert.compareArray(x, [1]);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-elision-next-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-elision-next-err.js
new file mode 100644
index 0000000000..aef4362e8b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-elision-next-err.js
@@ -0,0 +1,40 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-elision-next-err.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Rest element following elision elements (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    ArrayBindingPattern : [ Elisionopt BindingRestElement ]
+    1. If Elision is present, then
+       a. Let status be the result of performing
+          IteratorDestructuringAssignmentEvaluation of Elision with
+          iteratorRecord as the argument.
+       b. ReturnIfAbrupt(status).
+    2. Return the result of performing IteratorBindingInitialization for
+       BindingRestElement with iteratorRecord and environment as arguments.
+
+---*/
+var iter = (function*() { throw new Test262Error(); })();
+
+
+var f = async function*([, ...x] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-elision.js
new file mode 100644
index 0000000000..5c540ce210
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-elision.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-elision.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element following elision elements (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    ArrayBindingPattern : [ Elisionopt BindingRestElement ]
+    1. If Elision is present, then
+       a. Let status be the result of performing
+          IteratorDestructuringAssignmentEvaluation of Elision with
+          iteratorRecord as the argument.
+       b. ReturnIfAbrupt(status).
+    2. Return the result of performing IteratorBindingInitialization for
+       BindingRestElement with iteratorRecord and environment as arguments.
+---*/
+var values = [1, 2, 3, 4, 5];
+
+
+var callCount = 0;
+var f;
+f = async function*([ , , ...x] = values) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 3);
+  assert.sameValue(x[1], 4);
+  assert.sameValue(x[2], 5);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-exhausted.js
new file mode 100644
index 0000000000..b5ed8bba94
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-exhausted.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: RestElement applied to an exhausted iterator (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. If environment is undefined, return PutValue(lhs, A).
+          ii. Return InitializeReferencedBinding(lhs, A).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([, , ...x] = [1, 2]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-iter-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-iter-step-err.js
new file mode 100644
index 0000000000..7ca7b599e0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-iter-step-err.js
@@ -0,0 +1,51 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-iter-step-err.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       a. If iteratorRecord.[[done]] is false,
+          i. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+          ii. If next is an abrupt completion, set iteratorRecord.[[done]] to
+              true.
+          iii. ReturnIfAbrupt(next).
+
+---*/
+var first = 0;
+var second = 0;
+var iter = function*() {
+  first += 1;
+  throw new Test262Error();
+  second += 1;
+}();
+
+
+var f = async function*([...x] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+iter.next();
+assert.sameValue(first, 1);
+assert.sameValue(second, 0, 'Iterator is closed following abrupt completion.');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-iter-val-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-iter-val-err.js
new file mode 100644
index 0000000000..2ddd428cc7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id-iter-val-err.js
@@ -0,0 +1,53 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-iter-val-err.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       c. Let nextValue be IteratorValue(next).
+       d. If nextValue is an abrupt completion, set iteratorRecord.[[done]] to
+          true.
+       e. ReturnIfAbrupt(nextValue).
+
+---*/
+var poisonedValue = Object.defineProperty({}, 'value', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return poisonedValue;
+    }
+  };
+};
+
+
+var f = async function*([...x] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id.js
new file mode 100644
index 0000000000..6c7eba3136
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-id.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Lone rest element (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    [...] 3. Let A be ArrayCreate(0). [...] 5. Repeat
+       [...]
+       f. Let status be CreateDataProperty(A, ToString (n), nextValue).
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([...x] = values) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-init-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-init-ary.js
new file mode 100644
index 0000000000..315022bdb1
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-init-ary.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-ary.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element (nested array pattern) does not support initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...[ x ] = []] = []) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-init-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-init-id.js
new file mode 100644
index 0000000000..629a101ae8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-init-id.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element (identifier) does not support initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...x = []] = []) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-init-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-init-obj.js
new file mode 100644
index 0000000000..e8a3d00057
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-init-obj.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-obj.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element (nested object pattern) does not support initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ x } = []] = []) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-not-final-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-not-final-ary.js
new file mode 100644
index 0000000000..1aa8204c80
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-not-final-ary.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-ary.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element (array binding pattern) may not be followed by any element (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...[x], y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-not-final-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-not-final-id.js
new file mode 100644
index 0000000000..53775afec8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-not-final-id.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element (identifier) may not be followed by any element (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...x, y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-not-final-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-not-final-obj.js
new file mode 100644
index 0000000000..126f67faf2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-not-final-obj.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-obj.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element (object binding pattern) may not be followed by any element (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ x }, y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-obj-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-obj-id.js
new file mode 100644
index 0000000000..78bb3714df
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-obj-id.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing an object binding pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ length }] = [1, 2, 3]) {
+  assert.sameValue(length, 3);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-obj-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-obj-prop-id.js
new file mode 100644
index 0000000000..627eb415fd
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-ary-ptrn-rest-obj-prop-id.js
@@ -0,0 +1,51 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing an object binding pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+let length = "outer";
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ 0: v, 1: w, 2: x, 3: y, length: z }] = [7, 8, 9]) {
+  assert.sameValue(v, 7);
+  assert.sameValue(w, 8);
+  assert.sameValue(x, 9);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, 3);
+
+  assert.sameValue(length, "outer", "the length prop is not set as a binding name");
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-init-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-init-null.js
new file mode 100644
index 0000000000..7dd2ae9189
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-init-null.js
@@ -0,0 +1,34 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-init-null.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (null) (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+var f = async function*({} = null) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-init-undefined.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-init-undefined.js
new file mode 100644
index 0000000000..1a77f81f97
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-init-undefined.js
@@ -0,0 +1,34 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-init-undefined.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (undefined) (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+var f = async function*({} = undefined) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-empty.js
new file mode 100644
index 0000000000..e8bb916fdc
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-empty.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: No property access occurs for an "empty" object binding pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+var accessCount = 0;
+var obj = Object.defineProperty({}, 'attr', {
+  get: function() {
+    accessCount += 1;
+  }
+});
+
+
+var callCount = 0;
+var f;
+f = async function*({} = obj) {
+  assert.sameValue(accessCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-get-value-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-get-value-err.js
new file mode 100644
index 0000000000..90acbe9178
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-get-value-err.js
@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-get-value-err.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. Let v be GetV(value, propertyName).
+    5. ReturnIfAbrupt(v).
+---*/
+var poisonedProperty = Object.defineProperty({}, 'poisoned', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+
+
+var f = async function*({ poisoned } = poisonedProperty) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-arrow.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..2dfd5f0955
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-arrow.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to arrow functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ arrow = () => {} } = {}) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-class.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-class.js
new file mode 100644
index 0000000000..0876058218
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-class.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-class.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ cls = class {}, xCls = class X {}, xCls2 = class { static name() {} } } = {}) {
+  assert.sameValue(cls.name, 'cls');
+  assert.notSameValue(xCls.name, 'xCls');
+  assert.notSameValue(xCls2.name, 'xCls2');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-cover.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..6336e2f23f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-cover.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-cover.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" functions "through" cover grammar (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ cover = (function () {}), xCover = (0, function() {})  } = {}) {
+  assert.sameValue(cover.name, 'cover');
+  assert.notSameValue(xCover.name, 'xCover');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-fn.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..aca89b9fa1
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-fn.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ fn = function () {}, xFn = function x() {} } = {}) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-gen.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..6cb5124175
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-gen.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ gen = function* () {}, xGen = function* x() {} } = {}) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-skipped.js
new file mode 100644
index 0000000000..b7eb41b496
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-skipped.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    [...]
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*({ w = counter(), x = counter(), y = counter(), z = counter() } = { w: null, x: 0, y: false, z: '' }) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-throws.js
new file mode 100644
index 0000000000..125e900d7c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-throws.js
@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Error thrown when evaluating the initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let  defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f = async function*({ x = thrower() } = {}) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-unresolvable.js
new file mode 100644
index 0000000000..1157b32783
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-init-unresolvable.js
@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f = async function*({ x = unresolvableReference } = {}) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-trailing-comma.js
new file mode 100644
index 0000000000..b716aa978d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-id-trailing-comma.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x, } = { x: 23 }) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-list-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-list-err.js
new file mode 100644
index 0000000000..4a78e90510
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-list-err.js
@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-list-err.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Binding property list evaluation is interrupted by an abrupt completion (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPropertyList : BindingPropertyList , BindingProperty
+
+    1. Let status be the result of performing BindingInitialization for
+       BindingPropertyList using value and environment as arguments.
+    2. ReturnIfAbrupt(status).
+---*/
+var initCount = 0;
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f = async function*({ a, b = thrower(), c = ++initCount } = {}) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+assert.sameValue(initCount, 0);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary-init.js
new file mode 100644
index 0000000000..713379e1a3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary-init.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" array binding pattern using initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ w: [x, y, z] = [4, 5, 6] } = {}) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary-trailing-comma.js
new file mode 100644
index 0000000000..c9f6024c27
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary-trailing-comma.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x: [y], } = { x: [45] }) {
+  assert.sameValue(y,45);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary-value-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary-value-null.js
new file mode 100644
index 0000000000..f264a3207f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary-value-null.js
@@ -0,0 +1,36 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-value-null.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" array binding pattern taking the `null` value (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f = async function*({ w: [x, y, z] = [4, 5, 6] } = { w: null }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary.js
new file mode 100644
index 0000000000..26ccfa962e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-ary.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" array binding pattern not using initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ w: [x, y, z] = [4, 5, 6] } = { w: [7, undefined, ] }) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, undefined);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-eval-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-eval-err.js
new file mode 100644
index 0000000000..3833f98795
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-eval-err.js
@@ -0,0 +1,38 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-eval-err.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Evaluation of property name returns an abrupt completion (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingProperty : PropertyName : BindingElement
+
+    1. Let P be the result of evaluating PropertyName
+    2. ReturnIfAbrupt(P).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f = async function*({ [thrower()]: x } = {}) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-get-value-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-get-value-err.js
new file mode 100644
index 0000000000..fa06bd0ff5
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-get-value-err.js
@@ -0,0 +1,43 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-get-value-err.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. Let v be GetV(value, propertyName).
+    2. ReturnIfAbrupt(v).
+---*/
+var initEvalCount = 0;
+var poisonedProperty = Object.defineProperty({}, 'poisoned', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+
+
+var f = async function*({ poisoned: x = ++initEvalCount } = poisonedProperty) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+assert.sameValue(initEvalCount, 0);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init-skipped.js
new file mode 100644
index 0000000000..a365c90c9e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init-skipped.js
@@ -0,0 +1,60 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+    [...]
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*({ s: t = counter(), u: v = counter(), w: x = counter(), y: z = counter() } = { s: null, u: 0, w: false, y: '' }) {
+  assert.sameValue(t, null);
+  assert.sameValue(v, 0);
+  assert.sameValue(x, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+
+  assert.throws(ReferenceError, function() {
+    s;
+  });
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init-throws.js
new file mode 100644
index 0000000000..b1b612b3dc
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init-throws.js
@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Error thrown when evaluating the initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f = async function*({ x: y = thrower() } = {}) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init-unresolvable.js
new file mode 100644
index 0000000000..690abe4d1f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init-unresolvable.js
@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f = async function*({ x: y = unresolvableReference } = {}) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init.js
new file mode 100644
index 0000000000..9a48e10248
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-init.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Binding as specified via property name, identifier, and initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x: y = 33 } = { }) {
+  assert.sameValue(y, 33);
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-trailing-comma.js
new file mode 100644
index 0000000000..e4f05cae84
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id-trailing-comma.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x: y, } = { x: 23 }) {
+  assert.sameValue(y, 23);
+
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id.js
new file mode 100644
index 0000000000..2849bf8730
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-id.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Binding as specified via property name and identifier (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x: y } = { x: 23 }) {
+  assert.sameValue(y, 23);
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj-init.js
new file mode 100644
index 0000000000..e21ac34081
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj-init.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern using initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ w: { x, y, z } = { x: 4, y: 5, z: 6 } } = { w: undefined }) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj-value-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj-value-null.js
new file mode 100644
index 0000000000..fb94ec3a2a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj-value-null.js
@@ -0,0 +1,36 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-value-null.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f = async function*({ w: { x, y, z } = { x: 4, y: 5, z: 6 } } = { w: null }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj-value-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj-value-undef.js
new file mode 100644
index 0000000000..c34e69dd2d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj-value-undef.js
@@ -0,0 +1,36 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-value-undef.case
+// - src/dstr-binding/error/async-gen-func-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f = async function*({ w: { x, y, z } = undefined } = { }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj.js
new file mode 100644
index 0000000000..631967b330
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-prop-obj.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern not using initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ w: { x, y, z } = { x: 4, y: 5, z: 6 } } = { w: { x: undefined, z: 7 } }) {
+  assert.sameValue(x, undefined);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, 7);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-rest-getter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-rest-getter.js
new file mode 100644
index 0000000000..a997f2e2e0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-rest-getter.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-getter.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Getter is called when obj is being deconstructed to a rest Object (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+---*/
+var count = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*({...x} = { get v() { count++; return 2; } }) {
+  assert.sameValue(count, 1);
+
+  verifyProperty(x, "v", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-rest-skip-non-enumerable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-rest-skip-non-enumerable.js
new file mode 100644
index 0000000000..da16d35feb
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-rest-skip-non-enumerable.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-skip-non-enumerable.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest object doesn't contain non-enumerable properties (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+---*/
+var o = {a: 3, b: 4};
+Object.defineProperty(o, "x", { value: 4, enumerable: false });
+
+
+var callCount = 0;
+var f;
+f = async function*({...rest} = o) {
+  assert.sameValue(rest.x, undefined);
+
+  verifyProperty(rest, "a", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 3
+  });
+
+  verifyProperty(rest, "b", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 4
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-rest-val-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-rest-val-obj.js
new file mode 100644
index 0000000000..1a9fd733fa
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/dflt-obj-ptrn-rest-val-obj.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-val-obj.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest object contains just unextracted data (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({a, b, ...rest} = {x: 1, y: 2, a: 5, b: 3}) {
+  assert.sameValue(rest.a, undefined);
+  assert.sameValue(rest.b, undefined);
+
+  verifyProperty(rest, "x", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 1
+  });
+
+  verifyProperty(rest, "y", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-close.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-close.js
new file mode 100644
index 0000000000..e643fc2117
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-close.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-close.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Iterator is closed when not exhausted by pattern evaluation (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: false };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([x]) {
+  assert.sameValue(doneCallCount, 1);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-get-err-array-prototype.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-get-err-array-prototype.js
new file mode 100644
index 0000000000..e61c4f9fb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-get-err-array-prototype.js
@@ -0,0 +1,47 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-get-err-array-prototype.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iteratorRecord be ? GetIterator(value).
+
+    GetIterator ( obj [ , hint [ , method ] ] )
+
+    [...]
+    4. Let iterator be ? Call(method, obj).
+
+    Call ( F, V [ , argumentsList ] )
+
+    [...]
+    2. If IsCallable(F) is false, throw a TypeError exception.
+
+---*/
+delete Array.prototype[Symbol.iterator];
+
+
+var f;
+f = async function* g([x, y, z]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([1, 2, 3]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-get-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-get-err.js
new file mode 100644
index 0000000000..3b1ec476c7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-get-err.js
@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-get-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iterator be GetIterator(value).
+    2. ReturnIfAbrupt(iterator).
+
+---*/
+var iter = {};
+iter[Symbol.iterator] = function() {
+  throw new Test262Error();
+};
+
+
+var f;
+f = async function* g([x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-no-close.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-no-close.js
new file mode 100644
index 0000000000..ea245d046b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-init-iter-no-close.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-no-close.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Iterator is not closed when exhausted by pattern evaluation (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: true };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([x]) {
+  assert.sameValue(doneCallCount, 0);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-name-iter-val.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-name-iter-val.js
new file mode 100644
index 0000000000..6d0148d7c8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-name-iter-val.js
@@ -0,0 +1,53 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-name-iter-val.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding with normal value iteration (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x, y, z]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elem-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elem-init.js
new file mode 100644
index 0000000000..7969a3eca1
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elem-init.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([[x, y, z] = [4, 5, 6]]) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elem-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elem-iter.js
new file mode 100644
index 0000000000..3c57987290
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elem-iter.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-iter.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([[x, y, z] = [4, 5, 6]]) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, 8);
+  assert.sameValue(z, 9);
+  callCount = callCount + 1;
+};
+
+f([[7, 8, 9]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elision-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elision-init.js
new file mode 100644
index 0000000000..7eee91f03b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elision-init.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([[,] = g()]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elision-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elision-iter.js
new file mode 100644
index 0000000000..f4e5703efc
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-elision-iter.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-iter.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var callCount = 0;
+function* g() {
+  callCount += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([[,] = g()]) {
+  assert.sameValue(callCount, 0);
+  callCount = callCount + 1;
+};
+
+f([[]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-empty-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-empty-init.js
new file mode 100644
index 0000000000..e2b6dd2eea
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-empty-init.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var initCount = 0;
+var iterCount = 0;
+var iter = function*() { iterCount += 1; }();
+
+
+var callCount = 0;
+var f;
+f = async function* h([[] = function() { initCount += 1; return iter; }()]) {
+  assert.sameValue(initCount, 1);
+  assert.sameValue(iterCount, 0);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-empty-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-empty-iter.js
new file mode 100644
index 0000000000..1006dd8154
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-empty-iter.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-iter.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function* h([[] = function() { initCount += 1; }()]) {
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f([[23]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-rest-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-rest-init.js
new file mode 100644
index 0000000000..c60c89885d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-rest-init.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+
+
+var callCount = 0;
+var f;
+f = async function* h([[...x] = values]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-rest-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-rest-iter.js
new file mode 100644
index 0000000000..984a15e9fc
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-rest-iter.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-iter.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function* h([[...x] = function() { initCount += 1; }()]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f([values]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-val-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-val-null.js
new file mode 100644
index 0000000000..66409abe80
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-ary-val-null.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-val-null.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Nested array destructuring with a null value (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iterator be GetIterator(value).
+    2. ReturnIfAbrupt(iterator).
+---*/
+
+
+var f;
+f = async function* g([[x]]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([null]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-exhausted.js
new file mode 100644
index 0000000000..8b5f242782
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-exhausted.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-exhausted.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Destructuring initializer with an exhausted iterator (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x = 23]) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-arrow.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..454e387c90
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-arrow.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding does assign name to arrow functions (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([arrow = () => {}]) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-class.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-class.js
new file mode 100644
index 0000000000..b1d642afd4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-class.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-class.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([cls = class {}, xCls = class X {}, xCls2 = class { static name() {} }]) {
+  assert.sameValue(cls.name, 'cls');
+  assert.notSameValue(xCls.name, 'xCls');
+  assert.notSameValue(xCls2.name, 'xCls2');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-cover.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..5623c8ad3d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-cover.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-cover.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding does assign name to "anonymous" functions "through" cover grammar (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([cover = (function () {}), xCover = (0, function() {})]) {
+  assert.sameValue(cover.name, 'cover');
+  assert.notSameValue(xCover.name, 'xCover');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-fn.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..775f3c884f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-fn.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([fn = function () {}, xFn = function x() {}]) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-gen.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..54a90d2fda
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-fn-name-gen.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([gen = function* () {}, xGen = function* x() {}]) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-hole.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-hole.js
new file mode 100644
index 0000000000..298b9d26a7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-hole.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-hole.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Destructuring initializer with a "hole" (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    SingleNameBinding : BindingIdentifier Initializeropt
+    [...] 6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v). 8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x = 23]) {
+  assert.sameValue(x, 23);
+  // another statement
+  callCount = callCount + 1;
+};
+
+f([,]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-skipped.js
new file mode 100644
index 0000000000..072a5db935
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-skipped.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function* h([w = counter(), x = counter(), y = counter(), z = counter()]) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f([null, 0, false, '']).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-throws.js
new file mode 100644
index 0000000000..6ca55f47f0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-throws.js
@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Destructuring initializer returns an abrupt completion (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+
+
+var f;
+f = async function* g([x = (function() { throw new Test262Error(); })()]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f([undefined]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-undef.js
new file mode 100644
index 0000000000..0e3fc16ad7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-undef.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-undef.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Destructuring initializer with an undefined value (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x = 23]) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f([undefined]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-unresolvable.js
new file mode 100644
index 0000000000..b872cf8984
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-init-unresolvable.js
@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f;
+f = async function* g([ x = unresolvableReference ]) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f([]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-complete.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-complete.js
new file mode 100644
index 0000000000..3eb02deb39
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-complete.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-complete.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding when value iteration completes (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x]) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-done.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-done.js
new file mode 100644
index 0000000000..901a1ca51f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-done.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-done.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([_, x]) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-step-err.js
new file mode 100644
index 0000000000..f40fab78f2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-step-err.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-step-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+
+---*/
+var g = {};
+g[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      throw new Test262Error();
+    }
+  };
+};
+
+
+var f;
+f = async function* g([x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(g);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-val-array-prototype.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-val-array-prototype.js
new file mode 100644
index 0000000000..c4fbfc407c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-val-array-prototype.js
@@ -0,0 +1,63 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val-array-prototype.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Array destructuring uses overriden Array.prototype[Symbol.iterator] (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializer_opt
+
+    1. Let bindingId be StringValue of BindingIdentifier.
+    2. Let lhs be ? ResolveBinding(bindingId, environment).
+    3. If iteratorRecord.[[Done]] is false, then
+        a. Let next be IteratorStep(iteratorRecord).
+        b. If next is an abrupt completion, set iteratorRecord.[[Done]] to true.
+        c. ReturnIfAbrupt(next).
+        d. If next is false, set iteratorRecord.[[Done]] to true.
+        e. Else,
+            i. Let v be IteratorValue(next).
+            ii. If v is an abrupt completion, set iteratorRecord.[[Done]] to true.
+            iii. ReturnIfAbrupt(v).
+    [...]
+    7. Return InitializeReferencedBinding(lhs, v).
+
+---*/
+Array.prototype[Symbol.iterator] = function* () {
+    if (this.length > 0) {
+        yield this[0];
+    }
+    if (this.length > 1) {
+        yield this[1];
+    }
+    if (this.length > 2) {
+        yield 42;
+    }
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([x, y, z]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 42);
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-val-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-val-err.js
new file mode 100644
index 0000000000..14b3f231cf
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-val-err.js
@@ -0,0 +1,59 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set iteratorRecord.[[done]] to
+              true.
+          iii. ReturnIfAbrupt(v).
+
+---*/
+var poisonedValue = Object.defineProperty({}, 'value', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+var g = {};
+g[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return poisonedValue;
+    }
+  };
+};
+
+
+var f;
+f = async function* g([x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(g);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-val.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-val.js
new file mode 100644
index 0000000000..3c34d924ac
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-id-iter-val.js
@@ -0,0 +1,53 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x, y, z]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-id-init.js
new file mode 100644
index 0000000000..7c411d6cb8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-id-init.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([{ x, y, z } = { x: 44, y: 55, z: 66 }]) {
+  assert.sameValue(x, 44);
+  assert.sameValue(y, 55);
+  assert.sameValue(z, 66);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-id.js
new file mode 100644
index 0000000000..253bef3b8e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-id.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([{ x, y, z } = { x: 44, y: 55, z: 66 }]) {
+  assert.sameValue(x, 11);
+  assert.sameValue(y, 22);
+  assert.sameValue(z, 33);
+  callCount = callCount + 1;
+};
+
+f([{ x: 11, y: 22, z: 33 }]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-prop-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-prop-id-init.js
new file mode 100644
index 0000000000..3e4f8eb2d3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-prop-id-init.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }]) {
+  assert.sameValue(v, 444);
+  assert.sameValue(x, 555);
+  assert.sameValue(z, 666);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-prop-id.js
new file mode 100644
index 0000000000..6b94949151
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-prop-id.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }]) {
+  assert.sameValue(v, 777);
+  assert.sameValue(x, 888);
+  assert.sameValue(z, 999);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f([{ u: 777, w: 888, y: 999 }]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-val-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-val-null.js
new file mode 100644
index 0000000000..eeb42baac0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-val-null.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-val-null.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Nested object destructuring with a null value (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ObjectBindingPattern
+
+    1. Let valid be RequireObjectCoercible(value).
+    2. ReturnIfAbrupt(valid).
+---*/
+
+
+var f;
+f = async function* g([{ x }]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([null]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-val-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-val-undef.js
new file mode 100644
index 0000000000..6ecf1380f7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elem-obj-val-undef.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-val-undef.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Nested object destructuring with a value of `undefined` (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ObjectBindingPattern
+
+    1. Let valid be RequireObjectCoercible(value).
+    2. ReturnIfAbrupt(valid).
+---*/
+
+
+var f;
+f = async function* g([{ x }]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elision-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elision-exhausted.js
new file mode 100644
index 0000000000..b286785f7e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elision-exhausted.js
@@ -0,0 +1,50 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision-exhausted.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Elision accepts exhausted iterator (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+    2. Return NormalCompletion(empty).
+
+---*/
+var iter = function*() {}();
+iter.next();
+
+
+var callCount = 0;
+var f;
+f = async function* h([,]) {
+  
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elision-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elision-step-err.js
new file mode 100644
index 0000000000..6436a3ff45
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elision-step-err.js
@@ -0,0 +1,55 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision-step-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Elision advances iterator and forwards abrupt completions (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+
+---*/
+var following = 0;
+var iter =function* () {
+  throw new Test262Error();
+  following += 1;
+}();
+
+
+var f;
+f = async function* g([,]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+iter.next();
+assert.sameValue(following, 0, 'Iterator was properly closed.');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elision.js
new file mode 100644
index 0000000000..0a798b1113
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-elision.js
@@ -0,0 +1,59 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Elision advances iterator (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([,]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f(g()).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-empty.js
new file mode 100644
index 0000000000..b064054dea
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-empty.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: No iteration occurs for an "empty" array binding pattern (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function* h([]) {
+  assert.sameValue(iterations, 0);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-elem.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-elem.js
new file mode 100644
index 0000000000..4c9774e603
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-elem.js
@@ -0,0 +1,66 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elem.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element containing an array BindingElementList pattern (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[x, y, z]]) {
+  assert.sameValue(x, 3);
+  assert.sameValue(y, 4);
+  assert.sameValue(z, 5);
+  callCount = callCount + 1;
+};
+
+f([3, 4, 5]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-elision.js
new file mode 100644
index 0000000000..654351cfce
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-elision.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elision.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element containing an elision (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[,]]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 1);
+  callCount = callCount + 1;
+};
+
+f(g()).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-empty.js
new file mode 100644
index 0000000000..632010b46c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-empty.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-empty.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element containing an "empty" array pattern (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[]]) {
+  assert.sameValue(iterations, 1);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-rest.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-rest.js
new file mode 100644
index 0000000000..cfb6f46f72
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-ary-rest.js
@@ -0,0 +1,51 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-rest.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element containing a rest element (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[...x]]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+
+  callCount = callCount + 1;
+};
+
+f(values).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-direct.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-direct.js
new file mode 100644
index 0000000000..701fa07dc9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-direct.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-direct.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Lone rest element (direct binding) (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+includes: [compareArray.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingIdentifier
+
+    [...]
+    2. Let A be ! ArrayCreate(0).
+    3. Let n be 0.
+    4. Repeat,
+        [...]
+        f. Perform ! CreateDataPropertyOrThrow(A, ! ToString(n), nextValue).
+        g. Set n to n + 1.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([...x]) {
+  assert(Array.isArray(x));
+  assert.compareArray(x, [1]);
+  callCount = callCount + 1;
+};
+
+f([1]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-elision-next-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-elision-next-err.js
new file mode 100644
index 0000000000..e9d1335f5a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-elision-next-err.js
@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-elision-next-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Rest element following elision elements (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    ArrayBindingPattern : [ Elisionopt BindingRestElement ]
+    1. If Elision is present, then
+       a. Let status be the result of performing
+          IteratorDestructuringAssignmentEvaluation of Elision with
+          iteratorRecord as the argument.
+       b. ReturnIfAbrupt(status).
+    2. Return the result of performing IteratorBindingInitialization for
+       BindingRestElement with iteratorRecord and environment as arguments.
+
+---*/
+var iter = (function*() { throw new Test262Error(); })();
+
+
+var f;
+f = async function* g([, ...x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-elision.js
new file mode 100644
index 0000000000..93215c2509
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-elision.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-elision.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element following elision elements (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    ArrayBindingPattern : [ Elisionopt BindingRestElement ]
+    1. If Elision is present, then
+       a. Let status be the result of performing
+          IteratorDestructuringAssignmentEvaluation of Elision with
+          iteratorRecord as the argument.
+       b. ReturnIfAbrupt(status).
+    2. Return the result of performing IteratorBindingInitialization for
+       BindingRestElement with iteratorRecord and environment as arguments.
+---*/
+var values = [1, 2, 3, 4, 5];
+
+
+var callCount = 0;
+var f;
+f = async function* h([ , , ...x]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 3);
+  assert.sameValue(x[1], 4);
+  assert.sameValue(x[2], 5);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f(values).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-exhausted.js
new file mode 100644
index 0000000000..93753206f8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-exhausted.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-exhausted.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: RestElement applied to an exhausted iterator (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. If environment is undefined, return PutValue(lhs, A).
+          ii. Return InitializeReferencedBinding(lhs, A).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([, , ...x]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 0);
+  callCount = callCount + 1;
+};
+
+f([1, 2]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-iter-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-iter-step-err.js
new file mode 100644
index 0000000000..2375a3d3f2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-iter-step-err.js
@@ -0,0 +1,52 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-iter-step-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       a. If iteratorRecord.[[done]] is false,
+          i. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+          ii. If next is an abrupt completion, set iteratorRecord.[[done]] to
+              true.
+          iii. ReturnIfAbrupt(next).
+
+---*/
+var first = 0;
+var second = 0;
+var iter = function*() {
+  first += 1;
+  throw new Test262Error();
+  second += 1;
+}();
+
+
+var f;
+f = async function* g([...x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+iter.next();
+assert.sameValue(first, 1);
+assert.sameValue(second, 0, 'Iterator is closed following abrupt completion.');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-iter-val-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-iter-val-err.js
new file mode 100644
index 0000000000..21023db9be
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id-iter-val-err.js
@@ -0,0 +1,54 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-iter-val-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       c. Let nextValue be IteratorValue(next).
+       d. If nextValue is an abrupt completion, set iteratorRecord.[[done]] to
+          true.
+       e. ReturnIfAbrupt(nextValue).
+
+---*/
+var poisonedValue = Object.defineProperty({}, 'value', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return poisonedValue;
+    }
+  };
+};
+
+
+var f;
+f = async function* g([...x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id.js
new file mode 100644
index 0000000000..41a1db43d5
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-id.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Lone rest element (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    [...] 3. Let A be ArrayCreate(0). [...] 5. Repeat
+       [...]
+       f. Let status be CreateDataProperty(A, ToString (n), nextValue).
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function* h([...x]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f(values).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-init-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-init-ary.js
new file mode 100644
index 0000000000..4e327b7d22
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-init-ary.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-ary.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element (nested array pattern) does not support initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[ x ] = []]) {
+  
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-init-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-init-id.js
new file mode 100644
index 0000000000..2ec762492c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-init-id.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element (identifier) does not support initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...x = []]) {
+  
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-init-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-init-obj.js
new file mode 100644
index 0000000000..fa7d8d369a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-init-obj.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-obj.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element (nested object pattern) does not support initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...{ x } = []]) {
+  
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-not-final-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-not-final-ary.js
new file mode 100644
index 0000000000..582a9482ad
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-not-final-ary.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-ary.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element (array binding pattern) may not be followed by any element (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[x], y]) {
+  
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-not-final-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-not-final-id.js
new file mode 100644
index 0000000000..6dcef40b7b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-not-final-id.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element (identifier) may not be followed by any element (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...x, y]) {
+  
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-not-final-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-not-final-obj.js
new file mode 100644
index 0000000000..c82783bab9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-not-final-obj.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-obj.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element (object binding pattern) may not be followed by any element (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...{ x }, y]) {
+  
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-obj-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-obj-id.js
new file mode 100644
index 0000000000..c9e5949560
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-obj-id.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element containing an object binding pattern (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([...{ length }]) {
+  assert.sameValue(length, 3);
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-obj-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-obj-prop-id.js
new file mode 100644
index 0000000000..eeaa2bb073
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-ary-ptrn-rest-obj-prop-id.js
@@ -0,0 +1,51 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest element containing an object binding pattern (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+let length = "outer";
+
+
+var callCount = 0;
+var f;
+f = async function* h([...{ 0: v, 1: w, 2: x, 3: y, length: z }]) {
+  assert.sameValue(v, 7);
+  assert.sameValue(w, 8);
+  assert.sameValue(x, 9);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, 3);
+
+  assert.sameValue(length, "outer", "the length prop is not set as a binding name");
+  callCount = callCount + 1;
+};
+
+f([7, 8, 9]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-close.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-close.js
new file mode 100644
index 0000000000..97eed460a6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-close.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-close.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Iterator is closed when not exhausted by pattern evaluation (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: false };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([x] = iter) {
+  assert.sameValue(doneCallCount, 1);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-get-err-array-prototype.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-get-err-array-prototype.js
new file mode 100644
index 0000000000..b1c34faf7f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-get-err-array-prototype.js
@@ -0,0 +1,47 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-get-err-array-prototype.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iteratorRecord be ? GetIterator(value).
+
+    GetIterator ( obj [ , hint [ , method ] ] )
+
+    [...]
+    4. Let iterator be ? Call(method, obj).
+
+    Call ( F, V [ , argumentsList ] )
+
+    [...]
+    2. If IsCallable(F) is false, throw a TypeError exception.
+
+---*/
+delete Array.prototype[Symbol.iterator];
+
+
+var f;
+f = async function* h([x, y, z] = [1, 2, 3]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-get-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-get-err.js
new file mode 100644
index 0000000000..3d2e6d697d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-get-err.js
@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-get-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iterator be GetIterator(value).
+    2. ReturnIfAbrupt(iterator).
+
+---*/
+var iter = {};
+iter[Symbol.iterator] = function() {
+  throw new Test262Error();
+};
+
+
+var f;
+f = async function* h([x] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-no-close.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-no-close.js
new file mode 100644
index 0000000000..1312d5b3fd
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-init-iter-no-close.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-no-close.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Iterator is not closed when exhausted by pattern evaluation (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: true };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([x] = iter) {
+  assert.sameValue(doneCallCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-name-iter-val.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-name-iter-val.js
new file mode 100644
index 0000000000..327f9a1b71
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-name-iter-val.js
@@ -0,0 +1,53 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-name-iter-val.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding with normal value iteration (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x, y, z] = [1, 2, 3]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elem-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elem-init.js
new file mode 100644
index 0000000000..1e94865542
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elem-init.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([[x, y, z] = [4, 5, 6]] = []) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elem-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elem-iter.js
new file mode 100644
index 0000000000..31c99d280e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elem-iter.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-iter.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([[x, y, z] = [4, 5, 6]] = [[7, 8, 9]]) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, 8);
+  assert.sameValue(z, 9);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elision-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elision-init.js
new file mode 100644
index 0000000000..f583d14e65
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elision-init.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([[,] = g()] = []) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elision-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elision-iter.js
new file mode 100644
index 0000000000..2ba8f9ff28
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-elision-iter.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-iter.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var callCount = 0;
+function* g() {
+  callCount += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([[,] = g()] = [[]]) {
+  assert.sameValue(callCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-empty-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-empty-init.js
new file mode 100644
index 0000000000..fee07a23e2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-empty-init.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var initCount = 0;
+var iterCount = 0;
+var iter = function*() { iterCount += 1; }();
+
+
+var callCount = 0;
+var f;
+f = async function* h([[] = function() { initCount += 1; return iter; }()] = []) {
+  assert.sameValue(initCount, 1);
+  assert.sameValue(iterCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-empty-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-empty-iter.js
new file mode 100644
index 0000000000..66fb127397
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-empty-iter.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-iter.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function* h([[] = function() { initCount += 1; }()] = [[23]]) {
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-rest-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-rest-init.js
new file mode 100644
index 0000000000..c9bb825ff7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-rest-init.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+
+
+var callCount = 0;
+var f;
+f = async function* h([[...x] = values] = []) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-rest-iter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-rest-iter.js
new file mode 100644
index 0000000000..bb52e4f49f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-rest-iter.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-iter.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function* h([[...x] = function() { initCount += 1; }()] = [values]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-val-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-val-null.js
new file mode 100644
index 0000000000..120c6e76bb
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-ary-val-null.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-val-null.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Nested array destructuring with a null value (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    1. Let iterator be GetIterator(value).
+    2. ReturnIfAbrupt(iterator).
+---*/
+
+
+var f;
+f = async function* h([[x]] = [null]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-exhausted.js
new file mode 100644
index 0000000000..adeaa103e9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-exhausted.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-exhausted.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Destructuring initializer with an exhausted iterator (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x = 23] = []) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-arrow.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..0ac4c493a1
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-arrow.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding does assign name to arrow functions (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([arrow = () => {}] = []) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-class.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-class.js
new file mode 100644
index 0000000000..324602ee51
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-class.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-class.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([cls = class {}, xCls = class X {}, xCls2 = class { static name() {} }] = []) {
+  assert.sameValue(cls.name, 'cls');
+  assert.notSameValue(xCls.name, 'xCls');
+  assert.notSameValue(xCls2.name, 'xCls2');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-cover.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..825c0113fe
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-cover.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-cover.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding does assign name to "anonymous" functions "through" cover grammar (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([cover = (function () {}), xCover = (0, function() {})] = []) {
+  assert.sameValue(cover.name, 'cover');
+  assert.notSameValue(xCover.name, 'xCover');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-fn.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..f0aa5d2090
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-fn.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([fn = function () {}, xFn = function x() {}] = []) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-gen.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..3ce1c5af16
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-fn-name-gen.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([gen = function* () {}, xGen = function* x() {}] = []) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-hole.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-hole.js
new file mode 100644
index 0000000000..23a7f9ffd5
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-hole.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-hole.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Destructuring initializer with a "hole" (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    SingleNameBinding : BindingIdentifier Initializeropt
+    [...] 6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v). 8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x = 23] = [,]) {
+  assert.sameValue(x, 23);
+  // another statement
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-skipped.js
new file mode 100644
index 0000000000..6542568429
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-skipped.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function* h([w = counter(), x = counter(), y = counter(), z = counter()] = [null, 0, false, '']) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-throws.js
new file mode 100644
index 0000000000..2bb0a406b6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-throws.js
@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Destructuring initializer returns an abrupt completion (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+
+
+var f;
+f = async function* h([x = (function() { throw new Test262Error(); })()] = [undefined]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-undef.js
new file mode 100644
index 0000000000..21afd82d2a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-undef.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-undef.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Destructuring initializer with an undefined value (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x = 23] = [undefined]) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-unresolvable.js
new file mode 100644
index 0000000000..71aca3bb97
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-init-unresolvable.js
@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f;
+f = async function* h([ x = unresolvableReference ] = []) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-complete.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-complete.js
new file mode 100644
index 0000000000..a97fe06963
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-complete.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-complete.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding when value iteration completes (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x] = []) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-done.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-done.js
new file mode 100644
index 0000000000..9bbabceafa
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-done.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-done.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([_, x] = []) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-step-err.js
new file mode 100644
index 0000000000..31842304c2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-step-err.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-step-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+
+---*/
+var g = {};
+g[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      throw new Test262Error();
+    }
+  };
+};
+
+
+var f;
+f = async function* h([x] = g) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-val-array-prototype.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-val-array-prototype.js
new file mode 100644
index 0000000000..6109699b86
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-val-array-prototype.js
@@ -0,0 +1,63 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val-array-prototype.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Array destructuring uses overriden Array.prototype[Symbol.iterator] (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializer_opt
+
+    1. Let bindingId be StringValue of BindingIdentifier.
+    2. Let lhs be ? ResolveBinding(bindingId, environment).
+    3. If iteratorRecord.[[Done]] is false, then
+        a. Let next be IteratorStep(iteratorRecord).
+        b. If next is an abrupt completion, set iteratorRecord.[[Done]] to true.
+        c. ReturnIfAbrupt(next).
+        d. If next is false, set iteratorRecord.[[Done]] to true.
+        e. Else,
+            i. Let v be IteratorValue(next).
+            ii. If v is an abrupt completion, set iteratorRecord.[[Done]] to true.
+            iii. ReturnIfAbrupt(v).
+    [...]
+    7. Return InitializeReferencedBinding(lhs, v).
+
+---*/
+Array.prototype[Symbol.iterator] = function* () {
+    if (this.length > 0) {
+        yield this[0];
+    }
+    if (this.length > 1) {
+        yield this[1];
+    }
+    if (this.length > 2) {
+        yield 42;
+    }
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([x, y, z] = [1, 2, 3]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 42);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-val-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-val-err.js
new file mode 100644
index 0000000000..3921b1ca21
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-val-err.js
@@ -0,0 +1,59 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set iteratorRecord.[[done]] to
+              true.
+          iii. ReturnIfAbrupt(v).
+
+---*/
+var poisonedValue = Object.defineProperty({}, 'value', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+var g = {};
+g[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return poisonedValue;
+    }
+  };
+};
+
+
+var f;
+f = async function* h([x] = g) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-val.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-val.js
new file mode 100644
index 0000000000..81c79b9e7f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-id-iter-val.js
@@ -0,0 +1,53 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([x, y, z] = [1, 2, 3]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-id-init.js
new file mode 100644
index 0000000000..0ea1e5cbad
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-id-init.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([{ x, y, z } = { x: 44, y: 55, z: 66 }] = []) {
+  assert.sameValue(x, 44);
+  assert.sameValue(y, 55);
+  assert.sameValue(z, 66);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-id.js
new file mode 100644
index 0000000000..aaa1578190
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-id.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([{ x, y, z } = { x: 44, y: 55, z: 66 }] = [{ x: 11, y: 22, z: 33 }]) {
+  assert.sameValue(x, 11);
+  assert.sameValue(y, 22);
+  assert.sameValue(z, 33);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-prop-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-prop-id-init.js
new file mode 100644
index 0000000000..981296a5d9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-prop-id-init.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }] = []) {
+  assert.sameValue(v, 444);
+  assert.sameValue(x, 555);
+  assert.sameValue(z, 666);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-prop-id.js
new file mode 100644
index 0000000000..25e1a68221
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-prop-id.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }] = [{ u: 777, w: 888, y: 999 }]) {
+  assert.sameValue(v, 777);
+  assert.sameValue(x, 888);
+  assert.sameValue(z, 999);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-val-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-val-null.js
new file mode 100644
index 0000000000..bfa0bbce60
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-val-null.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-val-null.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Nested object destructuring with a null value (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ObjectBindingPattern
+
+    1. Let valid be RequireObjectCoercible(value).
+    2. ReturnIfAbrupt(valid).
+---*/
+
+
+var f;
+f = async function* h([{ x }] = [null]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-val-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-val-undef.js
new file mode 100644
index 0000000000..bc14482743
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elem-obj-val-undef.js
@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-val-undef.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Nested object destructuring with a value of `undefined` (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+       e. Else
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ObjectBindingPattern
+
+    1. Let valid be RequireObjectCoercible(value).
+    2. ReturnIfAbrupt(valid).
+---*/
+
+
+var f;
+f = async function* h([{ x }] = []) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elision-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elision-exhausted.js
new file mode 100644
index 0000000000..74f6dfb70e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elision-exhausted.js
@@ -0,0 +1,50 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision-exhausted.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Elision accepts exhausted iterator (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+    2. Return NormalCompletion(empty).
+
+---*/
+var iter = function*() {}();
+iter.next();
+
+
+var callCount = 0;
+var f;
+f = async function* h([,] = iter) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elision-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elision-step-err.js
new file mode 100644
index 0000000000..69240fea46
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elision-step-err.js
@@ -0,0 +1,55 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision-step-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Elision advances iterator and forwards abrupt completions (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+
+---*/
+var following = 0;
+var iter =function* () {
+  throw new Test262Error();
+  following += 1;
+}();
+
+
+var f;
+f = async function* h([,] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+iter.next();
+assert.sameValue(following, 0, 'Iterator was properly closed.');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elision.js
new file mode 100644
index 0000000000..1d36274ae7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-elision.js
@@ -0,0 +1,59 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Elision advances iterator (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([,] = g()) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-empty.js
new file mode 100644
index 0000000000..7aa5bec2a6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-empty.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: No iteration occurs for an "empty" array binding pattern (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function* h([] = iter) {
+  assert.sameValue(iterations, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-elem.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-elem.js
new file mode 100644
index 0000000000..5c7ae5a707
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-elem.js
@@ -0,0 +1,66 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elem.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element containing an array BindingElementList pattern (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[x, y, z]] = [3, 4, 5]) {
+  assert.sameValue(x, 3);
+  assert.sameValue(y, 4);
+  assert.sameValue(z, 5);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-elision.js
new file mode 100644
index 0000000000..6c0da07989
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-elision.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elision.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element containing an elision (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[,]] = g()) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 1);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-empty.js
new file mode 100644
index 0000000000..bf3545990b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-empty.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-empty.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element containing an "empty" array pattern (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[]] = iter) {
+  assert.sameValue(iterations, 1);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-rest.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-rest.js
new file mode 100644
index 0000000000..b589d81032
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-ary-rest.js
@@ -0,0 +1,51 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-rest.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element containing a rest element (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[...x]] = values) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-direct.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-direct.js
new file mode 100644
index 0000000000..75851e9fe4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-direct.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-direct.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Lone rest element (direct binding) (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+includes: [compareArray.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingIdentifier
+
+    [...]
+    2. Let A be ! ArrayCreate(0).
+    3. Let n be 0.
+    4. Repeat,
+        [...]
+        f. Perform ! CreateDataPropertyOrThrow(A, ! ToString(n), nextValue).
+        g. Set n to n + 1.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([...x] = [1]) {
+  assert(Array.isArray(x));
+  assert.compareArray(x, [1]);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-elision-next-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-elision-next-err.js
new file mode 100644
index 0000000000..5ed81cbb24
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-elision-next-err.js
@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-elision-next-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element following elision elements (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    ArrayBindingPattern : [ Elisionopt BindingRestElement ]
+    1. If Elision is present, then
+       a. Let status be the result of performing
+          IteratorDestructuringAssignmentEvaluation of Elision with
+          iteratorRecord as the argument.
+       b. ReturnIfAbrupt(status).
+    2. Return the result of performing IteratorBindingInitialization for
+       BindingRestElement with iteratorRecord and environment as arguments.
+
+---*/
+var iter = (function*() { throw new Test262Error(); })();
+
+
+var f;
+f = async function* h([, ...x] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-elision.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-elision.js
new file mode 100644
index 0000000000..5a2b9ab978
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-elision.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-elision.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element following elision elements (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    ArrayBindingPattern : [ Elisionopt BindingRestElement ]
+    1. If Elision is present, then
+       a. Let status be the result of performing
+          IteratorDestructuringAssignmentEvaluation of Elision with
+          iteratorRecord as the argument.
+       b. ReturnIfAbrupt(status).
+    2. Return the result of performing IteratorBindingInitialization for
+       BindingRestElement with iteratorRecord and environment as arguments.
+---*/
+var values = [1, 2, 3, 4, 5];
+
+
+var callCount = 0;
+var f;
+f = async function* h([ , , ...x] = values) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 3);
+  assert.sameValue(x[1], 4);
+  assert.sameValue(x[2], 5);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-exhausted.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-exhausted.js
new file mode 100644
index 0000000000..fb028857bb
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-exhausted.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-exhausted.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: RestElement applied to an exhausted iterator (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. If environment is undefined, return PutValue(lhs, A).
+          ii. Return InitializeReferencedBinding(lhs, A).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([, , ...x] = [1, 2]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-iter-step-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-iter-step-err.js
new file mode 100644
index 0000000000..b3e198190c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-iter-step-err.js
@@ -0,0 +1,52 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-iter-step-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       a. If iteratorRecord.[[done]] is false,
+          i. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+          ii. If next is an abrupt completion, set iteratorRecord.[[done]] to
+              true.
+          iii. ReturnIfAbrupt(next).
+
+---*/
+var first = 0;
+var second = 0;
+var iter = function*() {
+  first += 1;
+  throw new Test262Error();
+  second += 1;
+}();
+
+
+var f;
+f = async function* h([...x] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+iter.next();
+assert.sameValue(first, 1);
+assert.sameValue(second, 0, 'Iterator is closed following abrupt completion.');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-iter-val-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-iter-val-err.js
new file mode 100644
index 0000000000..43f6f6a8bf
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id-iter-val-err.js
@@ -0,0 +1,54 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-iter-val-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       c. Let nextValue be IteratorValue(next).
+       d. If nextValue is an abrupt completion, set iteratorRecord.[[done]] to
+          true.
+       e. ReturnIfAbrupt(nextValue).
+
+---*/
+var poisonedValue = Object.defineProperty({}, 'value', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return poisonedValue;
+    }
+  };
+};
+
+
+var f;
+f = async function* h([...x] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id.js
new file mode 100644
index 0000000000..97d6324987
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-id.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Lone rest element (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    [...] 3. Let A be ArrayCreate(0). [...] 5. Repeat
+       [...]
+       f. Let status be CreateDataProperty(A, ToString (n), nextValue).
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function* h([...x] = values) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-init-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-init-ary.js
new file mode 100644
index 0000000000..23d0961319
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-init-ary.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-ary.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element (nested array pattern) does not support initializer (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[ x ] = []] = []) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-init-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-init-id.js
new file mode 100644
index 0000000000..cf38d6066a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-init-id.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element (identifier) does not support initializer (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...x = []] = []) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-init-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-init-obj.js
new file mode 100644
index 0000000000..beb9a382fc
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-init-obj.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-obj.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element (nested object pattern) does not support initializer (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...{ x } = []] = []) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-not-final-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-not-final-ary.js
new file mode 100644
index 0000000000..a718a00735
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-not-final-ary.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-ary.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element (array binding pattern) may not be followed by any element (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...[x], y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-not-final-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-not-final-id.js
new file mode 100644
index 0000000000..e16a19ebef
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-not-final-id.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element (identifier) may not be followed by any element (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...x, y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-not-final-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-not-final-obj.js
new file mode 100644
index 0000000000..bce88cfda8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-not-final-obj.js
@@ -0,0 +1,41 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-obj.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element (object binding pattern) may not be followed by any element (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+var f;
+f = async function* h([...{ x }, y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-obj-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-obj-id.js
new file mode 100644
index 0000000000..7dab228808
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-obj-id.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element containing an object binding pattern (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h([...{ length }] = [1, 2, 3]) {
+  assert.sameValue(length, 3);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-obj-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-obj-prop-id.js
new file mode 100644
index 0000000000..cf048a14be
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-ary-ptrn-rest-obj-prop-id.js
@@ -0,0 +1,51 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest element containing an object binding pattern (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+let length = "outer";
+
+
+var callCount = 0;
+var f;
+f = async function* h([...{ 0: v, 1: w, 2: x, 3: y, length: z }] = [7, 8, 9]) {
+  assert.sameValue(v, 7);
+  assert.sameValue(w, 8);
+  assert.sameValue(x, 9);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, 3);
+
+  assert.sameValue(length, "outer", "the length prop is not set as a binding name");
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-init-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-init-null.js
new file mode 100644
index 0000000000..bbd8e92f7f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-init-null.js
@@ -0,0 +1,35 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-init-null.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (null) (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+var f;
+f = async function* h({} = null) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-init-undefined.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-init-undefined.js
new file mode 100644
index 0000000000..ab1837b703
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-init-undefined.js
@@ -0,0 +1,35 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-init-undefined.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (undefined) (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+var f;
+f = async function* h({} = undefined) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-empty.js
new file mode 100644
index 0000000000..4203ec5310
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-empty.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: No property access occurs for an "empty" object binding pattern (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+var accessCount = 0;
+var obj = Object.defineProperty({}, 'attr', {
+  get: function() {
+    accessCount += 1;
+  }
+});
+
+
+var callCount = 0;
+var f;
+f = async function* h({} = obj) {
+  assert.sameValue(accessCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-get-value-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-get-value-err.js
new file mode 100644
index 0000000000..fedfbe2c13
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-get-value-err.js
@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-get-value-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. Let v be GetV(value, propertyName).
+    5. ReturnIfAbrupt(v).
+---*/
+var poisonedProperty = Object.defineProperty({}, 'poisoned', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+
+
+var f;
+f = async function* h({ poisoned } = poisonedProperty) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-arrow.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..4f73b0c6b4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-arrow.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to arrow functions (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ arrow = () => {} } = {}) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-class.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-class.js
new file mode 100644
index 0000000000..d414404cd6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-class.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-class.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ cls = class {}, xCls = class X {}, xCls2 = class { static name() {} } } = {}) {
+  assert.sameValue(cls.name, 'cls');
+  assert.notSameValue(xCls.name, 'xCls');
+  assert.notSameValue(xCls2.name, 'xCls2');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-cover.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..d78ddc2e04
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-cover.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-cover.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" functions "through" cover grammar (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ cover = (function () {}), xCover = (0, function() {})  } = {}) {
+  assert.sameValue(cover.name, 'cover');
+  assert.notSameValue(xCover.name, 'xCover');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-fn.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..26d4ecf6aa
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-fn.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ fn = function () {}, xFn = function x() {} } = {}) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-gen.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..f96d35b737
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-fn-name-gen.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ gen = function* () {}, xGen = function* x() {} } = {}) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-skipped.js
new file mode 100644
index 0000000000..f64179e602
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-skipped.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    [...]
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function* h({ w = counter(), x = counter(), y = counter(), z = counter() } = { w: null, x: 0, y: false, z: '' }) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-throws.js
new file mode 100644
index 0000000000..fcefde9ed8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-throws.js
@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Error thrown when evaluating the initializer (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let  defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function* h({ x = thrower() } = {}) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-unresolvable.js
new file mode 100644
index 0000000000..49b35989f6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-init-unresolvable.js
@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f;
+f = async function* h({ x = unresolvableReference } = {}) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-trailing-comma.js
new file mode 100644
index 0000000000..a52a41e217
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-id-trailing-comma.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ x, } = { x: 23 }) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-list-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-list-err.js
new file mode 100644
index 0000000000..dbc65e4f9d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-list-err.js
@@ -0,0 +1,43 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-list-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Binding property list evaluation is interrupted by an abrupt completion (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPropertyList : BindingPropertyList , BindingProperty
+
+    1. Let status be the result of performing BindingInitialization for
+       BindingPropertyList using value and environment as arguments.
+    2. ReturnIfAbrupt(status).
+---*/
+var initCount = 0;
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function* h({ a, b = thrower(), c = ++initCount } = {}) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+assert.sameValue(initCount, 0);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary-init.js
new file mode 100644
index 0000000000..6d8179c8e4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary-init.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" array binding pattern using initializer (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ w: [x, y, z] = [4, 5, 6] } = {}) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary-trailing-comma.js
new file mode 100644
index 0000000000..02fd64f2b9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary-trailing-comma.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ x: [y], } = { x: [45] }) {
+  assert.sameValue(y,45);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary-value-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary-value-null.js
new file mode 100644
index 0000000000..b3bafbf16e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary-value-null.js
@@ -0,0 +1,37 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-value-null.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" array binding pattern taking the `null` value (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f;
+f = async function* h({ w: [x, y, z] = [4, 5, 6] } = { w: null }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary.js
new file mode 100644
index 0000000000..91e70485c3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-ary.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" array binding pattern not using initializer (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ w: [x, y, z] = [4, 5, 6] } = { w: [7, undefined, ] }) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, undefined);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-eval-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-eval-err.js
new file mode 100644
index 0000000000..28d659c6fe
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-eval-err.js
@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-eval-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Evaluation of property name returns an abrupt completion (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingProperty : PropertyName : BindingElement
+
+    1. Let P be the result of evaluating PropertyName
+    2. ReturnIfAbrupt(P).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function* h({ [thrower()]: x } = {}) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-get-value-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-get-value-err.js
new file mode 100644
index 0000000000..3111195b04
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-get-value-err.js
@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-get-value-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. Let v be GetV(value, propertyName).
+    2. ReturnIfAbrupt(v).
+---*/
+var initEvalCount = 0;
+var poisonedProperty = Object.defineProperty({}, 'poisoned', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+
+
+var f;
+f = async function* h({ poisoned: x = ++initEvalCount } = poisonedProperty) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+assert.sameValue(initEvalCount, 0);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init-skipped.js
new file mode 100644
index 0000000000..b5a09de042
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init-skipped.js
@@ -0,0 +1,60 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+    [...]
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function* h({ s: t = counter(), u: v = counter(), w: x = counter(), y: z = counter() } = { s: null, u: 0, w: false, y: '' }) {
+  assert.sameValue(t, null);
+  assert.sameValue(v, 0);
+  assert.sameValue(x, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+
+  assert.throws(ReferenceError, function() {
+    s;
+  });
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init-throws.js
new file mode 100644
index 0000000000..7320fb73bc
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init-throws.js
@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Error thrown when evaluating the initializer (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function* h({ x: y = thrower() } = {}) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init-unresolvable.js
new file mode 100644
index 0000000000..aee05d469c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init-unresolvable.js
@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f;
+f = async function* h({ x: y = unresolvableReference } = {}) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init.js
new file mode 100644
index 0000000000..c4f79f4ee8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-init.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Binding as specified via property name, identifier, and initializer (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ x: y = 33 } = { }) {
+  assert.sameValue(y, 33);
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-trailing-comma.js
new file mode 100644
index 0000000000..d331e19fe6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id-trailing-comma.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ x: y, } = { x: 23 }) {
+  assert.sameValue(y, 23);
+
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id.js
new file mode 100644
index 0000000000..d390aaf442
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-id.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Binding as specified via property name and identifier (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ x: y } = { x: 23 }) {
+  assert.sameValue(y, 23);
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj-init.js
new file mode 100644
index 0000000000..02cb6a3f59
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj-init.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern using initializer (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ w: { x, y, z } = { x: 4, y: 5, z: 6 } } = { w: undefined }) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj-value-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj-value-null.js
new file mode 100644
index 0000000000..b63dc5ff74
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj-value-null.js
@@ -0,0 +1,37 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-value-null.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f;
+f = async function* h({ w: { x, y, z } = { x: 4, y: 5, z: 6 } } = { w: null }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj-value-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj-value-undef.js
new file mode 100644
index 0000000000..5fb1a5326d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj-value-undef.js
@@ -0,0 +1,37 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-value-undef.case
+// - src/dstr-binding/error/async-gen-func-named-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f;
+f = async function* h({ w: { x, y, z } = undefined } = { }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj.js
new file mode 100644
index 0000000000..d7f909c240
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-prop-obj.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern not using initializer (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ w: { x, y, z } = { x: 4, y: 5, z: 6 } } = { w: { x: undefined, z: 7 } }) {
+  assert.sameValue(x, undefined);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, 7);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-rest-getter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-rest-getter.js
new file mode 100644
index 0000000000..835028c927
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-rest-getter.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-getter.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Getter is called when obj is being deconstructed to a rest Object (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+---*/
+var count = 0;
+
+
+var callCount = 0;
+var f;
+f = async function* h({...x} = { get v() { count++; return 2; } }) {
+  assert.sameValue(count, 1);
+
+  verifyProperty(x, "v", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-rest-skip-non-enumerable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-rest-skip-non-enumerable.js
new file mode 100644
index 0000000000..436ad98c52
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-rest-skip-non-enumerable.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-skip-non-enumerable.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest object doesn't contain non-enumerable properties (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+---*/
+var o = {a: 3, b: 4};
+Object.defineProperty(o, "x", { value: 4, enumerable: false });
+
+
+var callCount = 0;
+var f;
+f = async function* h({...rest} = o) {
+  assert.sameValue(rest.x, undefined);
+
+  verifyProperty(rest, "a", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 3
+  });
+
+  verifyProperty(rest, "b", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 4
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-rest-val-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-rest-val-obj.js
new file mode 100644
index 0000000000..8e3b2d68d9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-dflt-obj-ptrn-rest-val-obj.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-val-obj.case
+// - src/dstr-binding/default/async-gen-func-named-expr-dflt.template
+/*---
+description: Rest object contains just unextracted data (async generator named function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({a, b, ...rest} = {x: 1, y: 2, a: 5, b: 3}) {
+  assert.sameValue(rest.a, undefined);
+  assert.sameValue(rest.b, undefined);
+
+  verifyProperty(rest, "x", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 1
+  });
+
+  verifyProperty(rest, "y", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-init-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-init-null.js
new file mode 100644
index 0000000000..b6064a769c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-init-null.js
@@ -0,0 +1,35 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-init-null.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (null) (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+var f;
+f = async function* g({}) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f(null);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-init-undefined.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-init-undefined.js
new file mode 100644
index 0000000000..04aa4f1ad3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-init-undefined.js
@@ -0,0 +1,35 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-init-undefined.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (undefined) (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+var f;
+f = async function* g({}) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f(undefined);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-empty.js
new file mode 100644
index 0000000000..272465447b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-empty.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: No property access occurs for an "empty" object binding pattern (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+var accessCount = 0;
+var obj = Object.defineProperty({}, 'attr', {
+  get: function() {
+    accessCount += 1;
+  }
+});
+
+
+var callCount = 0;
+var f;
+f = async function* h({}) {
+  assert.sameValue(accessCount, 0);
+  callCount = callCount + 1;
+};
+
+f(obj).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-get-value-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-get-value-err.js
new file mode 100644
index 0000000000..2ce4f8cb03
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-get-value-err.js
@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-get-value-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. Let v be GetV(value, propertyName).
+    5. ReturnIfAbrupt(v).
+---*/
+var poisonedProperty = Object.defineProperty({}, 'poisoned', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+
+
+var f;
+f = async function* g({ poisoned }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(poisonedProperty);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-arrow.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..c1b3726490
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-arrow.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding assigns `name` to arrow functions (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ arrow = () => {} }) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-class.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-class.js
new file mode 100644
index 0000000000..46bd7d576e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-class.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-class.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ cls = class {}, xCls = class X {}, xCls2 = class { static name() {} } }) {
+  assert.sameValue(cls.name, 'cls');
+  assert.notSameValue(xCls.name, 'xCls');
+  assert.notSameValue(xCls2.name, 'xCls2');
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-cover.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..d5a02c3d37
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-cover.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-cover.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" functions "through" cover grammar (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ cover = (function () {}), xCover = (0, function() {})  }) {
+  assert.sameValue(cover.name, 'cover');
+  assert.notSameValue(xCover.name, 'xCover');
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-fn.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..5f4250b5c5
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-fn.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ fn = function () {}, xFn = function x() {} }) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-gen.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..af3ec9ce67
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-fn-name-gen.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ gen = function* () {}, xGen = function* x() {} }) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-skipped.js
new file mode 100644
index 0000000000..47c7d43e89
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-skipped.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    [...]
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function* h({ w = counter(), x = counter(), y = counter(), z = counter() }) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f({ w: null, x: 0, y: false, z: '' }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-throws.js
new file mode 100644
index 0000000000..c0ca107850
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-throws.js
@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Error thrown when evaluating the initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let  defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function* g({ x = thrower() }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-unresolvable.js
new file mode 100644
index 0000000000..e5744abc21
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-init-unresolvable.js
@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f;
+f = async function* g({ x = unresolvableReference }) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-trailing-comma.js
new file mode 100644
index 0000000000..44d8dec12d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-id-trailing-comma.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ x, }) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f({ x: 23 }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-list-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-list-err.js
new file mode 100644
index 0000000000..dce2e24d1f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-list-err.js
@@ -0,0 +1,43 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-list-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Binding property list evaluation is interrupted by an abrupt completion (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPropertyList : BindingPropertyList , BindingProperty
+
+    1. Let status be the result of performing BindingInitialization for
+       BindingPropertyList using value and environment as arguments.
+    2. ReturnIfAbrupt(status).
+---*/
+var initCount = 0;
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function* g({ a, b = thrower(), c = ++initCount }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f({});
+});
+
+assert.sameValue(initCount, 0);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary-init.js
new file mode 100644
index 0000000000..3d70802764
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary-init.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Object binding pattern with "nested" array binding pattern using initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ w: [x, y, z] = [4, 5, 6] }) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary-trailing-comma.js
new file mode 100644
index 0000000000..5404707935
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary-trailing-comma.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ x: [y], }) {
+  assert.sameValue(y,45);
+  callCount = callCount + 1;
+};
+
+f({ x: [45] }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary-value-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary-value-null.js
new file mode 100644
index 0000000000..1e62e078ff
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary-value-null.js
@@ -0,0 +1,37 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-value-null.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Object binding pattern with "nested" array binding pattern taking the `null` value (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f;
+f = async function* g({ w: [x, y, z] = [4, 5, 6] }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f({ w: null });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary.js
new file mode 100644
index 0000000000..690381f4dd
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-ary.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Object binding pattern with "nested" array binding pattern not using initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ w: [x, y, z] = [4, 5, 6] }) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, undefined);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f({ w: [7, undefined, ] }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-eval-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-eval-err.js
new file mode 100644
index 0000000000..67697b9b61
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-eval-err.js
@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-eval-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Evaluation of property name returns an abrupt completion (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingProperty : PropertyName : BindingElement
+
+    1. Let P be the result of evaluating PropertyName
+    2. ReturnIfAbrupt(P).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function* g({ [thrower()]: x }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-get-value-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-get-value-err.js
new file mode 100644
index 0000000000..8dc3082a20
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-get-value-err.js
@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-get-value-err.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. Let v be GetV(value, propertyName).
+    2. ReturnIfAbrupt(v).
+---*/
+var initEvalCount = 0;
+var poisonedProperty = Object.defineProperty({}, 'poisoned', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+
+
+var f;
+f = async function* g({ poisoned: x = ++initEvalCount }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(poisonedProperty);
+});
+
+assert.sameValue(initEvalCount, 0);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init-skipped.js
new file mode 100644
index 0000000000..4ecda5b046
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init-skipped.js
@@ -0,0 +1,60 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+    [...]
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function* h({ s: t = counter(), u: v = counter(), w: x = counter(), y: z = counter() }) {
+  assert.sameValue(t, null);
+  assert.sameValue(v, 0);
+  assert.sameValue(x, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+
+  assert.throws(ReferenceError, function() {
+    s;
+  });
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f({ s: null, u: 0, w: false, y: '' }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init-throws.js
new file mode 100644
index 0000000000..b5a8e64958
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init-throws.js
@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Error thrown when evaluating the initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function* g({ x: y = thrower() }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init-unresolvable.js
new file mode 100644
index 0000000000..933524d160
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init-unresolvable.js
@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f;
+f = async function* g({ x: y = unresolvableReference }) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init.js
new file mode 100644
index 0000000000..330c9c31e0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-init.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Binding as specified via property name, identifier, and initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ x: y = 33 }) {
+  assert.sameValue(y, 33);
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f({ }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-trailing-comma.js
new file mode 100644
index 0000000000..180b8ad3ff
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id-trailing-comma.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ x: y, }) {
+  assert.sameValue(y, 23);
+
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f({ x: 23 }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id.js
new file mode 100644
index 0000000000..55a3888db7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-id.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Binding as specified via property name and identifier (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ x: y }) {
+  assert.sameValue(y, 23);
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f({ x: 23 }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj-init.js
new file mode 100644
index 0000000000..a45c18df19
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj-init.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-init.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Object binding pattern with "nested" object binding pattern using initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ w: { x, y, z } = { x: 4, y: 5, z: 6 } }) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f({ w: undefined }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj-value-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj-value-null.js
new file mode 100644
index 0000000000..0659e717ab
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj-value-null.js
@@ -0,0 +1,37 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-value-null.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f;
+f = async function* g({ w: { x, y, z } = { x: 4, y: 5, z: 6 } }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f({ w: null });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj-value-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj-value-undef.js
new file mode 100644
index 0000000000..dc7f82ff9c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj-value-undef.js
@@ -0,0 +1,37 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-value-undef.case
+// - src/dstr-binding/error/async-gen-func-named-expr.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f;
+f = async function* g({ w: { x, y, z } = undefined }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f({ });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj.js
new file mode 100644
index 0000000000..306dab2a35
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-prop-obj.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Object binding pattern with "nested" object binding pattern not using initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({ w: { x, y, z } = { x: 4, y: 5, z: 6 } }) {
+  assert.sameValue(x, undefined);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, 7);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f({ w: { x: undefined, z: 7 } }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-rest-getter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-rest-getter.js
new file mode 100644
index 0000000000..b70ccb3c62
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-rest-getter.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-getter.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Getter is called when obj is being deconstructed to a rest Object (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+---*/
+var count = 0;
+
+
+var callCount = 0;
+var f;
+f = async function* h({...x}) {
+  assert.sameValue(count, 1);
+
+  verifyProperty(x, "v", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+
+f({ get v() { count++; return 2; } }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-rest-skip-non-enumerable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-rest-skip-non-enumerable.js
new file mode 100644
index 0000000000..c605036f44
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-rest-skip-non-enumerable.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-skip-non-enumerable.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest object doesn't contain non-enumerable properties (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+---*/
+var o = {a: 3, b: 4};
+Object.defineProperty(o, "x", { value: 4, enumerable: false });
+
+
+var callCount = 0;
+var f;
+f = async function* h({...rest}) {
+  assert.sameValue(rest.x, undefined);
+
+  verifyProperty(rest, "a", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 3
+  });
+
+  verifyProperty(rest, "b", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 4
+  });
+  callCount = callCount + 1;
+};
+
+f(o).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-rest-val-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-rest-val-obj.js
new file mode 100644
index 0000000000..588fc7aa2e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/named-obj-ptrn-rest-val-obj.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-val-obj.case
+// - src/dstr-binding/default/async-gen-func-named-expr.template
+/*---
+description: Rest object contains just unextracted data (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* h({a, b, ...rest}) {
+  assert.sameValue(rest.a, undefined);
+  assert.sameValue(rest.b, undefined);
+
+  verifyProperty(rest, "x", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 1
+  });
+
+  verifyProperty(rest, "y", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+
+f({x: 1, y: 2, a: 5, b: 3}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-init-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-init-null.js
new file mode 100644
index 0000000000..5ee8a4d505
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-init-null.js
@@ -0,0 +1,35 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-init-null.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (null) (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+var f;
+f = async function*({}) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f(null);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-init-undefined.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-init-undefined.js
new file mode 100644
index 0000000000..68a135e842
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-init-undefined.js
@@ -0,0 +1,35 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-init-undefined.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (undefined) (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+var f;
+f = async function*({}) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f(undefined);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-empty.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-empty.js
new file mode 100644
index 0000000000..77f185ecff
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-empty.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: No property access occurs for an "empty" object binding pattern (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+var accessCount = 0;
+var obj = Object.defineProperty({}, 'attr', {
+  get: function() {
+    accessCount += 1;
+  }
+});
+
+
+var callCount = 0;
+var f;
+f = async function*({}) {
+  assert.sameValue(accessCount, 0);
+  callCount = callCount + 1;
+};
+
+f(obj).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-get-value-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-get-value-err.js
new file mode 100644
index 0000000000..d258e6ba13
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-get-value-err.js
@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-get-value-err.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. Let v be GetV(value, propertyName).
+    5. ReturnIfAbrupt(v).
+---*/
+var poisonedProperty = Object.defineProperty({}, 'poisoned', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+
+
+var f;
+f = async function*({ poisoned }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(poisonedProperty);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-arrow.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..7fef7c2cfa
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-arrow.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding assigns `name` to arrow functions (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ arrow = () => {} }) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-class.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-class.js
new file mode 100644
index 0000000000..58527f2ae2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-class.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-class.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ cls = class {}, xCls = class X {}, xCls2 = class { static name() {} } }) {
+  assert.sameValue(cls.name, 'cls');
+  assert.notSameValue(xCls.name, 'xCls');
+  assert.notSameValue(xCls2.name, 'xCls2');
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-cover.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..b0f0cfc3c3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-cover.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-cover.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" functions "through" cover grammar (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ cover = (function () {}), xCover = (0, function() {})  }) {
+  assert.sameValue(cover.name, 'cover');
+  assert.notSameValue(xCover.name, 'xCover');
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-fn.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..32dcb5b8af
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-fn.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ fn = function () {}, xFn = function x() {} }) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-gen.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..af444cc6b4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-fn-name-gen.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ gen = function* () {}, xGen = function* x() {} }) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-skipped.js
new file mode 100644
index 0000000000..3c3c36ac3c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-skipped.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    [...]
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*({ w = counter(), x = counter(), y = counter(), z = counter() }) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f({ w: null, x: 0, y: false, z: '' }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-throws.js
new file mode 100644
index 0000000000..21e1b974c2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-throws.js
@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Error thrown when evaluating the initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let  defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function*({ x = thrower() }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-unresolvable.js
new file mode 100644
index 0000000000..588d2be359
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-init-unresolvable.js
@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f;
+f = async function*({ x = unresolvableReference }) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-trailing-comma.js
new file mode 100644
index 0000000000..2b7e794cf6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-id-trailing-comma.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x, }) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f({ x: 23 }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-list-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-list-err.js
new file mode 100644
index 0000000000..c8f8712f50
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-list-err.js
@@ -0,0 +1,43 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-list-err.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Binding property list evaluation is interrupted by an abrupt completion (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPropertyList : BindingPropertyList , BindingProperty
+
+    1. Let status be the result of performing BindingInitialization for
+       BindingPropertyList using value and environment as arguments.
+    2. ReturnIfAbrupt(status).
+---*/
+var initCount = 0;
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function*({ a, b = thrower(), c = ++initCount }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f({});
+});
+
+assert.sameValue(initCount, 0);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary-init.js
new file mode 100644
index 0000000000..57b8569b9f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary-init.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Object binding pattern with "nested" array binding pattern using initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ w: [x, y, z] = [4, 5, 6] }) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary-trailing-comma.js
new file mode 100644
index 0000000000..4f12609b64
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary-trailing-comma.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x: [y], }) {
+  assert.sameValue(y,45);
+  callCount = callCount + 1;
+};
+
+f({ x: [45] }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary-value-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary-value-null.js
new file mode 100644
index 0000000000..43054ce5d6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary-value-null.js
@@ -0,0 +1,37 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-value-null.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Object binding pattern with "nested" array binding pattern taking the `null` value (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f;
+f = async function*({ w: [x, y, z] = [4, 5, 6] }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f({ w: null });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary.js
new file mode 100644
index 0000000000..5716990e0c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-ary.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Object binding pattern with "nested" array binding pattern not using initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ w: [x, y, z] = [4, 5, 6] }) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, undefined);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f({ w: [7, undefined, ] }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-eval-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-eval-err.js
new file mode 100644
index 0000000000..0f52b003a3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-eval-err.js
@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-eval-err.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Evaluation of property name returns an abrupt completion (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingProperty : PropertyName : BindingElement
+
+    1. Let P be the result of evaluating PropertyName
+    2. ReturnIfAbrupt(P).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function*({ [thrower()]: x }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-get-value-err.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-get-value-err.js
new file mode 100644
index 0000000000..9e249c829b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-get-value-err.js
@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-get-value-err.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    1. Let v be GetV(value, propertyName).
+    2. ReturnIfAbrupt(v).
+---*/
+var initEvalCount = 0;
+var poisonedProperty = Object.defineProperty({}, 'poisoned', {
+  get: function() {
+    throw new Test262Error();
+  }
+});
+
+
+var f;
+f = async function*({ poisoned: x = ++initEvalCount }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(poisonedProperty);
+});
+
+assert.sameValue(initEvalCount, 0);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init-skipped.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init-skipped.js
new file mode 100644
index 0000000000..95ac9fcdf0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init-skipped.js
@@ -0,0 +1,60 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+    [...]
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*({ s: t = counter(), u: v = counter(), w: x = counter(), y: z = counter() }) {
+  assert.sameValue(t, null);
+  assert.sameValue(v, 0);
+  assert.sameValue(x, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+
+  assert.throws(ReferenceError, function() {
+    s;
+  });
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f({ s: null, u: 0, w: false, y: '' }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init-throws.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init-throws.js
new file mode 100644
index 0000000000..27cc7c83c3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init-throws.js
@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-throws.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Error thrown when evaluating the initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+---*/
+function thrower() {
+  throw new Test262Error();
+}
+
+
+var f;
+f = async function*({ x: y = thrower() }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init-unresolvable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init-unresolvable.js
new file mode 100644
index 0000000000..e900051220
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init-unresolvable.js
@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init-unresolvable.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    BindingElement : BindingPattern Initializeropt
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+
+    6.2.3.1 GetValue (V)
+
+    1. ReturnIfAbrupt(V).
+    2. If Type(V) is not Reference, return V.
+    3. Let base be GetBase(V).
+    4. If IsUnresolvableReference(V), throw a ReferenceError exception.
+---*/
+
+
+var f;
+f = async function*({ x: y = unresolvableReference }) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init.js
new file mode 100644
index 0000000000..38fdb10700
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-init.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Binding as specified via property name, identifier, and initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x: y = 33 }) {
+  assert.sameValue(y, 33);
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f({ }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-trailing-comma.js
new file mode 100644
index 0000000000..2ad14b75bc
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id-trailing-comma.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x: y, }) {
+  assert.sameValue(y, 23);
+
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f({ x: 23 }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id.js
new file mode 100644
index 0000000000..3e3ddef41d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-id.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Binding as specified via property name and identifier (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x: y }) {
+  assert.sameValue(y, 23);
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+
+f({ x: 23 }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj-init.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj-init.js
new file mode 100644
index 0000000000..9e44c37e5f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj-init.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Object binding pattern with "nested" object binding pattern using initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ w: { x, y, z } = { x: 4, y: 5, z: 6 } }) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f({ w: undefined }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj-value-null.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj-value-null.js
new file mode 100644
index 0000000000..7d603c62f6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj-value-null.js
@@ -0,0 +1,37 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-value-null.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f;
+f = async function*({ w: { x, y, z } = { x: 4, y: 5, z: 6 } }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f({ w: null });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj-value-undef.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj-value-undef.js
new file mode 100644
index 0000000000..ea685e7b2b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj-value-undef.js
@@ -0,0 +1,37 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-value-undef.case
+// - src/dstr-binding/error/async-gen-func-expr.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var f;
+f = async function*({ w: { x, y, z } = undefined }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f({ });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj.js
new file mode 100644
index 0000000000..2fb16ded2a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-prop-obj.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Object binding pattern with "nested" object binding pattern not using initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       [...]
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ w: { x, y, z } = { x: 4, y: 5, z: 6 } }) {
+  assert.sameValue(x, undefined);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, 7);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f({ w: { x: undefined, z: 7 } }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-rest-getter.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-rest-getter.js
new file mode 100644
index 0000000000..207ba7de4a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-rest-getter.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-getter.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Getter is called when obj is being deconstructed to a rest Object (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+---*/
+var count = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*({...x}) {
+  assert.sameValue(count, 1);
+
+  verifyProperty(x, "v", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+
+f({ get v() { count++; return 2; } }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-rest-skip-non-enumerable.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-rest-skip-non-enumerable.js
new file mode 100644
index 0000000000..0b2a97f109
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-rest-skip-non-enumerable.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-skip-non-enumerable.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest object doesn't contain non-enumerable properties (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+---*/
+var o = {a: 3, b: 4};
+Object.defineProperty(o, "x", { value: 4, enumerable: false });
+
+
+var callCount = 0;
+var f;
+f = async function*({...rest}) {
+  assert.sameValue(rest.x, undefined);
+
+  verifyProperty(rest, "a", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 3
+  });
+
+  verifyProperty(rest, "b", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 4
+  });
+  callCount = callCount + 1;
+};
+
+f(o).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-rest-val-obj.js b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-rest-val-obj.js
new file mode 100644
index 0000000000..fd09928e16
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/obj-ptrn-rest-val-obj.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-val-obj.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest object contains just unextracted data (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({a, b, ...rest}) {
+  assert.sameValue(rest.a, undefined);
+  assert.sameValue(rest.b, undefined);
+
+  verifyProperty(rest, "x", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 1
+  });
+
+  verifyProperty(rest, "y", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+
+f({x: 1, y: 2, a: 5, b: 3}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/dstr/shell.js b/js/src/tests/test262/language/expressions/async-generator/dstr/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/dstr/shell.js
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-NSPL-with-USD.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-NSPL-with-USD.js
new file mode 100644
index 0000000000..f09c58e53e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-NSPL-with-USD.js
@@ -0,0 +1,19 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-async-generator-function-definitions-static-semantics-early-errors
+description: >
+  It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+  IsSimpleParameterList of UniqueFormalParameters is false.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*(x = 1) {"use strict"});
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-arguments-in-formal-parameters-strict.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-arguments-in-formal-parameters-strict.js
new file mode 100644
index 0000000000..f6a7b3a300
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-arguments-in-formal-parameters-strict.js
@@ -0,0 +1,20 @@
+// |reftest| error:SyntaxError
+'use strict';
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-async-generator-function-definitions-static-semantics-early-errors
+description: >
+  It is a SyntaxError if FormalParameters contains arguments in strict mode.
+negative:
+  phase: parse
+  type: SyntaxError
+flags: [onlyStrict]
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*(arguments) { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-await-as-function-binding-identifier.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-await-as-function-binding-identifier.js
new file mode 100644
index 0000000000..fc2b60d1f5
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-await-as-function-binding-identifier.js
@@ -0,0 +1,18 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-identifiers-static-semantics-early-errors
+description: >
+  `await` is not a valid BindingIdentifier for AsyncGeneratorExpressions.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function* await() { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-binding-identifier-arguments-strict.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-binding-identifier-arguments-strict.js
new file mode 100644
index 0000000000..7f9c53b5ce
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-binding-identifier-arguments-strict.js
@@ -0,0 +1,21 @@
+// |reftest| error:SyntaxError
+'use strict';
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-identifiers-static-semantics-early-errors
+description: >
+  If the source code matching this production is strict code, it is a
+  Syntax Error if BindingIdentifier is the IdentifierName arguments.
+negative:
+  phase: parse
+  type: SyntaxError
+flags: [onlyStrict]
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function* arguments() { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-binding-identifier-eval-strict.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-binding-identifier-eval-strict.js
new file mode 100644
index 0000000000..45a8922d7a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-binding-identifier-eval-strict.js
@@ -0,0 +1,21 @@
+// |reftest| error:SyntaxError
+'use strict';
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-identifiers-static-semantics-early-errors
+description: >
+  If the source code matching this production is strict code, it is a
+  Syntax Error if BindingIdentifier is the IdentifierName eval.
+negative:
+  phase: parse
+  type: SyntaxError
+flags: [onlyStrict]
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function* eval() { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-body-contains-super-call.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-body-contains-super-call.js
new file mode 100644
index 0000000000..b074cbc7dd
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-body-contains-super-call.js
@@ -0,0 +1,18 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-async-generator-function-definitions-static-semantics-early-errors
+description: >
+  It is a syntax error if AsyncGeneratorBody contains SuperCall is true.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*() { super(); });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-body-contains-super-property.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-body-contains-super-property.js
new file mode 100644
index 0000000000..a62022973e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-body-contains-super-property.js
@@ -0,0 +1,18 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-async-generator-function-definitions-static-semantics-early-errors
+description: >
+  It is a syntax error if AsyncGeneratorBody contains SuperProperty is true.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*() { super.prop; });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-eval-in-formal-parameters-strict.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-eval-in-formal-parameters-strict.js
new file mode 100644
index 0000000000..cd5284a157
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-eval-in-formal-parameters-strict.js
@@ -0,0 +1,20 @@
+// |reftest| error:SyntaxError
+'use strict';
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-strict-mode-of-ecmascript
+description: >
+  It is a SyntaxError if FormalParameters contains eval in strict mode.
+negative:
+  phase: parse
+  type: SyntaxError
+flags: [onlyStrict]
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*(eval) { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-body-duplicate-const.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-body-duplicate-const.js
new file mode 100644
index 0000000000..9be10e9601
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-body-duplicate-const.js
@@ -0,0 +1,22 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-async-generator-function-definitions-static-semantics-early-errors
+description: >
+  It is a SyntaxError if BoundNames of FormalParameters also occurs in the
+  LexicallyDeclaredNames of AsyncFunctionBody
+info: |
+  It is a Syntax Error if any element of the BoundNames of FormalParameters
+  also occurs in the LexicallyDeclaredNames of GeneratorBody.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*(a) { const a = 0; });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-body-duplicate-let.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-body-duplicate-let.js
new file mode 100644
index 0000000000..aea4309f8e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-body-duplicate-let.js
@@ -0,0 +1,19 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-async-generator-function-definitions-static-semantics-early-errors
+description: >
+  It is a SyntaxError if BoundNames of FormalParameters also occurs in the
+  LexicallyDeclaredNames of AsyncFunctionBody
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*(a) { let a; });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-await-expr.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-await-expr.js
new file mode 100644
index 0000000000..5a6677d8e8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-await-expr.js
@@ -0,0 +1,18 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-async-generator-function-definitions-static-semantics-early-errors
+description: >
+  It is a Syntax Error if FormalParameters Contains AwaitExpression is true.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*(x = await 1) { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-await.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-await.js
new file mode 100644
index 0000000000..9bf880d200
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-await.js
@@ -0,0 +1,19 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-identifiers-static-semantics-early-errors
+description: >
+  `await` is a reserved keyword within async generator function bodies and may
+  not be used as the binding identifier of a parameter.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*(await) { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-super-call.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-super-call.js
new file mode 100644
index 0000000000..07801e74eb
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-super-call.js
@@ -0,0 +1,18 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-async-generator-function-definitions-static-semantics-early-errors
+description: >
+  It is a syntax error if FormalParameters contains SuperCall is true.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*(a = super()) { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-super-property.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-super-property.js
new file mode 100644
index 0000000000..344914d8d6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-super-property.js
@@ -0,0 +1,18 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-async-generator-function-definitions-static-semantics-early-errors
+description: >
+  It is a syntax error if FormalParameters contains SuperProperty is true.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*(a = super.prop) { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-yield-expr.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-yield-expr.js
new file mode 100644
index 0000000000..3e24c30203
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-yield-expr.js
@@ -0,0 +1,18 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-async-generator-function-definitions-static-semantics-early-errors
+description: >
+  It is a Syntax Error if FormalParameters Contains YieldExpression is true.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*(x = yield) { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-yield.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-yield.js
new file mode 100644
index 0000000000..e30271bf70
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-formals-contains-yield.js
@@ -0,0 +1,19 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-identifiers-static-semantics-early-errors
+description: >
+  `yield` is a reserved keyword within async generator function bodies and may
+  not be used as the binding identifier of a parameter.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*(yield) { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-label-name-await.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-label-name-await.js
new file mode 100644
index 0000000000..c19d21c7ce
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-label-name-await.js
@@ -0,0 +1,25 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-identifiers-static-semantics-early-errors
+description: >
+  `await` is a reserved keyword within async generator function bodies and may
+  not be used as a label.
+info: |
+  BindingIdentifier : await
+
+  It is a Syntax Error if this production has an [Await] parameter.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*() {
+  await: 1;
+});
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-label-name-yield.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-label-name-yield.js
new file mode 100644
index 0000000000..3565f700f8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-label-name-yield.js
@@ -0,0 +1,27 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-identifiers-static-semantics-early-errors
+description: >
+  `yield` is a reserved keyword within async generator function bodies and may
+  not be used as a label.
+info: |
+  BindingIdentifier : Identifier
+  LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has an [Await] parameter and
+    StringValue of Identifier is "await".
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*() {
+  yield: 1;
+});
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-not-simple-assignment-target.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-not-simple-assignment-target.js
new file mode 100644
index 0000000000..7f49ef1285
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-not-simple-assignment-target.js
@@ -0,0 +1,18 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: prod-LeftHandSideExpression
+description: >
+  Async generator function expressions are not a simple assignment target.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*() { } = 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-yield-as-function-binding-identifier.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-yield-as-function-binding-identifier.js
new file mode 100644
index 0000000000..36a3a63894
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-yield-as-function-binding-identifier.js
@@ -0,0 +1,18 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-async-generator-function-definitions-static-semantics-early-errors
+description: >
+  `yield` is not a valid BindingIdentifier for AsyncGeneratorExpressions.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function* yield() { });
diff --git a/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-yield-star-after-newline.js b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-yield-star-after-newline.js
new file mode 100644
index 0000000000..6867a3aa5b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/early-errors-expression-yield-star-after-newline.js
@@ -0,0 +1,21 @@
+// |reftest| error:SyntaxError
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-generator-function-definitions
+description: >
+  A newline may not precede the `*` token in a `yield` expression.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+(async function*() {
+  yield
+  * 1;
+});
diff --git a/js/src/tests/test262/language/expressions/async-generator/escaped-async.js b/js/src/tests/test262/language/expressions/async-generator/escaped-async.js
new file mode 100644
index 0000000000..6d0692ea29
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/escaped-async.js
@@ -0,0 +1,25 @@
+// |reftest| error:SyntaxError
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-grammar-notation
+description: >
+  The `async` contextual keyword must not contain Unicode escape sequences.
+info: |
+  Terminal symbols are shown
+  in fixed width font, both in the productions of the grammars and throughout this
+  specification whenever the text directly refers to such a terminal symbol. These
+  are to appear in a script exactly as written. All terminal symbol code points
+  specified in this way are to be understood as the appropriate Unicode code points
+  from the Basic Latin range, as opposed to any similar-looking code points from
+  other Unicode ranges.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+void \u0061sync function* f(){};
diff --git a/js/src/tests/test262/language/expressions/async-generator/eval-body-proto-realm.js b/js/src/tests/test262/language/expressions/async-generator/eval-body-proto-realm.js
new file mode 100644
index 0000000000..1c48e3b768
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/eval-body-proto-realm.js
@@ -0,0 +1,54 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-asyncgenerator-definitions-evaluatebody
+description: >
+  Default [[Prototype]] value derived from realm of the async generator function.
+info: |
+  Runtime Semantics: EvaluateBody
+
+  ...
+  2. Let generator be ? OrdinaryCreateFromConstructor(functionObject, "%AsyncGeneratorPrototype%", « ... »).
+  3. Perform ! AsyncGeneratorStart(generator, FunctionBody).
+  4. Return Completion { [[Type]]: return, [[Value]]: generator, [[Target]]: empty }.
+
+  OrdinaryCreateFromConstructor ( constructor, intrinsicDefaultProto [ , internalSlotsList ] )
+
+  ...
+  2. Let proto be ? GetPrototypeFromConstructor(constructor, intrinsicDefaultProto).
+  3. Return ObjectCreate(proto, internalSlotsList).
+
+  GetPrototypeFromConstructor ( constructor, intrinsicDefaultProto )
+
+  ...
+  3. Let proto be ? Get(constructor, 'prototype').
+  4. If Type(proto) is not Object, then
+    a. Let realm be ? GetFunctionRealm(constructor).
+    b. Set proto to realm's intrinsic object named intrinsicDefaultProto.
+  5. Return proto.
+features: [async-iteration, cross-realm, Symbol]
+---*/
+
+var other = $262.createRealm().global;
+var fn = other.eval('(0, async function* () {})');
+var AsyncGeneratorPrototype = Object.getPrototypeOf(fn.prototype);
+
+fn.prototype = undefined;
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is undefined');
+
+fn.prototype = null;
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is null');
+
+fn.prototype = true;
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is a Boolean');
+
+fn.prototype = 'str';
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is a String');
+
+fn.prototype = Symbol();
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is a Symbol');
+
+fn.prototype = 0;
+assert.sameValue(Object.getPrototypeOf(fn()), AsyncGeneratorPrototype, 'fn.prototype is a Number');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/eval-var-scope-syntax-err.js b/js/src/tests/test262/language/expressions/async-generator/eval-var-scope-syntax-err.js
new file mode 100644
index 0000000000..d157cd3e4b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/eval-var-scope-syntax-err.js
@@ -0,0 +1,40 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/eval-var-scope-syntax-err.case
+// - src/function-forms/error-no-strict/async-gen-func-expr.template
+/*---
+description: sloppy direct eval in params introduces var (async generator function expression in sloppy code)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated, noStrict]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    
+    Runtime Semantics: IteratorBindingInitialization
+    FormalParameter : BindingElement
+
+    1. Return the result of performing IteratorBindingInitialization for BindingElement with arguments iteratorRecord and environment.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*(a = eval("var a = 42")) {
+  
+  callCount = callCount + 1;
+};
+
+assert.throws(SyntaxError, function() {
+  f();
+});
+assert.sameValue(callCount, 0, 'generator function body not evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/expression-await-as-yield-operand.js b/js/src/tests/test262/language/expressions/async-generator/expression-await-as-yield-operand.js
new file mode 100644
index 0000000000..ece1fe83c9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/expression-await-as-yield-operand.js
@@ -0,0 +1,26 @@
+// |reftest| async
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-generator-function-definitions
+description: >
+  AwaitExpressions are valid operands to yield expressions.
+flags: [async]
+features: [async-iteration]
+---*/
+
+var iter = (async function*() {
+  yield await "a";
+})();
+
+iter.next().then(function(result) {
+  assert.sameValue(result.value, "a", 'First result `value`');
+  assert.sameValue(result.done, false, 'First result `done` flag');
+}).then(undefined, $DONE);
+
+iter.next().then(function(result) {
+  assert.sameValue(result.value, undefined, 'Second result `value`');
+  assert.sameValue(result.done, true, 'Second result `done` flag');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/expression-await-promise-as-yield-operand.js b/js/src/tests/test262/language/expressions/async-generator/expression-await-promise-as-yield-operand.js
new file mode 100644
index 0000000000..385b014d44
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/expression-await-promise-as-yield-operand.js
@@ -0,0 +1,28 @@
+// |reftest| async
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-generator-function-definitions
+description: >
+  AwaitExpressions are valid operands to yield expressions.
+flags: [async]
+features: [async-iteration]
+---*/
+
+var iter = (async function*() {
+  yield await new Promise(function(resolve) {
+    resolve("a");
+  });
+})();
+
+iter.next().then(function(result) {
+  assert.sameValue(result.value, "a", 'First result `value`');
+  assert.sameValue(result.done, false, 'First result `done` flag');
+}).then(undefined, $DONE);
+
+iter.next().then(function(result) {
+  assert.sameValue(result.value, undefined, 'Second result `value`');
+  assert.sameValue(result.done, true, 'Second result `done` flag');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/expression-await-thenable-as-yield-operand.js b/js/src/tests/test262/language/expressions/async-generator/expression-await-thenable-as-yield-operand.js
new file mode 100644
index 0000000000..37877d4333
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/expression-await-thenable-as-yield-operand.js
@@ -0,0 +1,32 @@
+// |reftest| async
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-generator-function-definitions
+description: >
+  AwaitExpressions are valid operands to yield expressions.
+flags: [async]
+features: [async-iteration]
+---*/
+
+var thenable = {
+  then: function(resolve, reject) {
+    resolve("a");
+  }
+};
+
+var iter = (async function*() {
+  yield await thenable;
+})();
+
+iter.next().then(function(result) {
+  assert.sameValue(result.value, "a", 'First result `value`');
+  assert.sameValue(result.done, false, 'First result `done` flag');
+}).then(undefined, $DONE);
+
+iter.next().then(function(result) {
+  assert.sameValue(result.value, undefined, 'Second result `value`');
+  assert.sameValue(result.done, true, 'Second result `done` flag');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/expression-yield-as-operand.js b/js/src/tests/test262/language/expressions/async-generator/expression-yield-as-operand.js
new file mode 100644
index 0000000000..d64aba1715
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/expression-yield-as-operand.js
@@ -0,0 +1,33 @@
+// |reftest| async
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-generator-function-definitions
+description: >
+  `yield` expressions may be used as the right-hand-side of other `yield`
+  expressions.
+flags: [async]
+features: [async-iteration]
+---*/
+
+var g = async function*() {
+  yield yield 1;
+};
+
+var iter = g();
+iter.next().then(function(result) {
+  assert.sameValue(result.value, 1, 'First result `value`');
+  assert.sameValue(result.done, false, 'First result `done` flag');
+}).then(undefined, $DONE);
+
+iter.next().then(function(result) {
+  assert.sameValue(result.value, undefined, 'Second result `value`');
+  assert.sameValue(result.done, false, 'Second result `done` flag');
+}).then(undefined, $DONE);
+
+iter.next().then(function(result) {
+  assert.sameValue(result.value, undefined, 'Third result `value`');
+  assert.sameValue(result.done, true, 'Thid result `done` flag');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/expression-yield-as-statement.js b/js/src/tests/test262/language/expressions/async-generator/expression-yield-as-statement.js
new file mode 100644
index 0000000000..9cff52a2af
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/expression-yield-as-statement.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-generator-function-definitions
+description: >
+  `yield` is a valid statement within async generator function bodies.
+flags: [async]
+features: [async-iteration]
+---*/
+
+var g1 = async function*() { yield; };
+var g2 = async function*() { yield 1; };
+
+var iter1 = g1();
+iter1.next().then(function(result) {
+  assert.sameValue(
+    result.value, undefined, "Without right-hand-side: first result `value`");
+  assert.sameValue(
+    result.done, false, "Without right-hand-side: first result `done` flag");
+}).then(undefined, $DONE);
+iter1.next().then(function(result) {
+  assert.sameValue(
+    result.value, undefined, "Without right-hand-side: second result `value`");
+  assert.sameValue(
+    result.done, true, "Without right-hand-side: second result `done` flag");
+}).then(undefined, $DONE);
+
+var iter2 = g2();
+iter2.next().then(function(result) {
+  assert.sameValue(
+    result.value, 1, "With right-hand-side: first result `value`");
+  assert.sameValue(
+    result.done, false, "With right-hand-side: first result `done` flag");
+}).then(undefined, $DONE);
+iter2.next().then(function(result) {
+  assert.sameValue(
+    result.value, undefined, "With right-hand-side: second result `value`");
+  assert.sameValue(
+    result.done, true, "With right-hand-side: second result `done` flag");
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/expression-yield-newline.js b/js/src/tests/test262/language/expressions/async-generator/expression-yield-newline.js
new file mode 100644
index 0000000000..541f1a862c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/expression-yield-newline.js
@@ -0,0 +1,28 @@
+// |reftest| async
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-generator-function-definitions
+description: >
+  Newlines terminate `yield` expressions.
+flags: [async]
+features: [async-iteration]
+---*/
+
+var g = async function*() {
+  yield
+  1;
+};
+
+var iter = g();
+iter.next().then(function(result) {
+  assert.sameValue(result.value, undefined, 'First result `value`');
+  assert.sameValue(result.done, false, 'First result `done` flag');
+}).then(undefined, $DONE);
+
+iter.next().then(function(result) {
+  assert.sameValue(result.value, undefined, 'Second result `value`');
+  assert.sameValue(result.done, true, 'Second result `done` flag');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/expression-yield-star-before-newline.js b/js/src/tests/test262/language/expressions/async-generator/expression-yield-star-before-newline.js
new file mode 100644
index 0000000000..f5511e44cf
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/expression-yield-star-before-newline.js
@@ -0,0 +1,22 @@
+// |reftest| async
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Caitlin Potter <caitp@igalia.com>
+esid: sec-generator-function-definitions
+description: >
+  The right-hand side of a `yield *` expression may appear on a new line.
+flags: [async]
+features: [async-iteration]
+---*/
+
+var g = async function*() {};
+
+(async function*() {
+  yield*
+  g();
+})().next().then(function(result) {
+  assert.sameValue(result.value, undefined);
+  assert.sameValue(result.done, true);
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-func-expr-forbidden-ext-direct-access-prop-arguments.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-func-expr-forbidden-ext-direct-access-prop-arguments.js
new file mode 100644
index 0000000000..3695816892
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-func-expr-forbidden-ext-direct-access-prop-arguments.js
@@ -0,0 +1,39 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/forbidden-ext-direct-access-prop-arguments.case
+// - src/function-forms/forbidden-extensions/bullet-one/async-gen-func-expr.template
+/*---
+description: Forbidden extension, f.arguments (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    ECMAScript function objects defined using syntactic constructors in strict mode code must
+    not be created with own properties named "caller" or "arguments". Such own properties also
+    must not be created for function objects defined using an ArrowFunction, MethodDefinition,
+    GeneratorDeclaration, GeneratorExpression, AsyncGeneratorDeclaration, AsyncGeneratorExpression,
+    ClassDeclaration, ClassExpression, AsyncFunctionDeclaration, AsyncFunctionExpression, or
+    AsyncArrowFunction regardless of whether the definition is contained in strict mode code.
+    Built-in functions, strict functions created using the Function constructor, generator functions
+    created using the Generator constructor, async functions created using the AsyncFunction
+    constructor, and functions created using the bind method also must not be created with such own
+    properties.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*() {
+  assert.sameValue(f.hasOwnProperty("arguments"), false);
+  callCount++;
+};
+
+f().next()
+  .then(() => {
+    assert.sameValue(callCount, 1, 'function body evaluated');
+  }, $DONE).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-func-expr-forbidden-ext-direct-access-prop-caller.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-func-expr-forbidden-ext-direct-access-prop-caller.js
new file mode 100644
index 0000000000..4baefa87a8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-func-expr-forbidden-ext-direct-access-prop-caller.js
@@ -0,0 +1,39 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/forbidden-ext-direct-access-prop-caller.case
+// - src/function-forms/forbidden-extensions/bullet-one/async-gen-func-expr.template
+/*---
+description: Forbidden extension, o.caller (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    ECMAScript function objects defined using syntactic constructors in strict mode code must
+    not be created with own properties named "caller" or "arguments". Such own properties also
+    must not be created for function objects defined using an ArrowFunction, MethodDefinition,
+    GeneratorDeclaration, GeneratorExpression, AsyncGeneratorDeclaration, AsyncGeneratorExpression,
+    ClassDeclaration, ClassExpression, AsyncFunctionDeclaration, AsyncFunctionExpression, or
+    AsyncArrowFunction regardless of whether the definition is contained in strict mode code.
+    Built-in functions, strict functions created using the Function constructor, generator functions
+    created using the Generator constructor, async functions created using the AsyncFunction
+    constructor, and functions created using the bind method also must not be created with such own
+    properties.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*() {
+  assert.sameValue(f.hasOwnProperty("caller"), false);
+  callCount++;
+};
+
+f().next()
+  .then(() => {
+    assert.sameValue(callCount, 1, 'function body evaluated');
+  }, $DONE).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-named-func-expr-forbidden-ext-direct-access-prop-arguments.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-named-func-expr-forbidden-ext-direct-access-prop-arguments.js
new file mode 100644
index 0000000000..01c75de1b4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-named-func-expr-forbidden-ext-direct-access-prop-arguments.js
@@ -0,0 +1,39 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/forbidden-ext-direct-access-prop-arguments.case
+// - src/function-forms/forbidden-extensions/bullet-one/async-gen-named-func-expr.template
+/*---
+description: Forbidden extension, f.arguments (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+
+    ECMAScript function objects defined using syntactic constructors in strict mode code must
+    not be created with own properties named "caller" or "arguments". Such own properties also
+    must not be created for function objects defined using an ArrowFunction, MethodDefinition,
+    GeneratorDeclaration, GeneratorExpression, AsyncGeneratorDeclaration, AsyncGeneratorExpression,
+    ClassDeclaration, ClassExpression, AsyncFunctionDeclaration, AsyncFunctionExpression, or
+    AsyncArrowFunction regardless of whether the definition is contained in strict mode code.
+    Built-in functions, strict functions created using the Function constructor, generator functions
+    created using the Generator constructor, async functions created using the AsyncFunction
+    constructor, and functions created using the bind method also must not be created with such own
+    properties.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* g() {
+  assert.sameValue(f.hasOwnProperty("arguments"), false);
+  callCount++;
+};
+
+f().next()
+  .then(() => {
+    assert.sameValue(callCount, 1, 'function body evaluated');
+  }, $DONE).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-named-func-expr-forbidden-ext-direct-access-prop-caller.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-named-func-expr-forbidden-ext-direct-access-prop-caller.js
new file mode 100644
index 0000000000..939d7cb830
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/async-gen-named-func-expr-forbidden-ext-direct-access-prop-caller.js
@@ -0,0 +1,39 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/forbidden-ext-direct-access-prop-caller.case
+// - src/function-forms/forbidden-extensions/bullet-one/async-gen-named-func-expr.template
+/*---
+description: Forbidden extension, o.caller (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+
+    ECMAScript function objects defined using syntactic constructors in strict mode code must
+    not be created with own properties named "caller" or "arguments". Such own properties also
+    must not be created for function objects defined using an ArrowFunction, MethodDefinition,
+    GeneratorDeclaration, GeneratorExpression, AsyncGeneratorDeclaration, AsyncGeneratorExpression,
+    ClassDeclaration, ClassExpression, AsyncFunctionDeclaration, AsyncFunctionExpression, or
+    AsyncArrowFunction regardless of whether the definition is contained in strict mode code.
+    Built-in functions, strict functions created using the Function constructor, generator functions
+    created using the Generator constructor, async functions created using the AsyncFunction
+    constructor, and functions created using the bind method also must not be created with such own
+    properties.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* g() {
+  assert.sameValue(f.hasOwnProperty("caller"), false);
+  callCount++;
+};
+
+f().next()
+  .then(() => {
+    assert.sameValue(callCount, 1, 'function body evaluated');
+  }, $DONE).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/browser.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/browser.js
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/shell.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b1/shell.js
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-func-expr-forbidden-ext-indirect-access-own-prop-caller-get.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-func-expr-forbidden-ext-indirect-access-own-prop-caller-get.js
new file mode 100644
index 0000000000..3b1af7907a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-func-expr-forbidden-ext-indirect-access-own-prop-caller-get.js
@@ -0,0 +1,65 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/forbidden-ext-indirect-access-own-prop-caller-get.case
+// - src/function-forms/forbidden-extensions/bullet-two/async-gen-func-expr.template
+/*---
+description: Forbidden extension, o.caller (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    If an implementation extends any function object with an own property named "caller" the value of
+    that property, as observed using [[Get]] or [[GetOwnProperty]], must not be a strict function
+    object. If it is an accessor property, the function that is the value of the property's [[Get]]
+    attribute must never return a strict function when called.
+
+---*/
+var CALLER_OWN_PROPERTY_DOES_NOT_EXIST = Symbol();
+function inner() {
+  // This property may exist, but is forbidden from having a value that is a strict function object
+  return inner.hasOwnProperty("caller")
+    ? inner.caller
+    : CALLER_OWN_PROPERTY_DOES_NOT_EXIST;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*() {
+  "use strict";
+  // This and the following conditional value is set in the test's .case file.
+  // For every test that has a "true" value here, there is a
+  // corresponding test that has a "false" value here.
+  // They are generated from two different case files, which use
+  // the same templates.
+  let descriptor = Object.getOwnPropertyDescriptor(inner, "caller");
+  if (descriptor && descriptor.configurable && true) {
+    Object.defineProperty(inner, "caller", {get(){return 1}});
+  }
+  var result = inner();
+  if (descriptor && descriptor.configurable && true) {
+    assert.sameValue(result, 1, 'If this test defined an own "caller" property on the inner function, then it should be accessible and should return the value it was set to.');
+  }
+  // "CALLER_OWN_PROPERTY_DOES_NOT_EXIST" is from
+  // forbidden-ext-indirect-access-prop-caller.case
+  //
+  // If the function object "inner" has an own property
+  // named "caller", then its value will be returned.
+  //
+  // If the function object "inner" DOES NOT have an
+  // own property named "caller", then the symbol
+  // CALLER_OWN_PROPERTY_DOES_NOT_EXIST will be returned.
+  if (result !== CALLER_OWN_PROPERTY_DOES_NOT_EXIST) {
+    assert.notSameValue(result, f);
+  }
+  callCount++;
+};
+
+f().next()
+  .then(() => {
+    assert.sameValue(callCount, 1, 'function body evaluated');
+  }, $DONE).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-func-expr-forbidden-ext-indirect-access-own-prop-caller-value.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-func-expr-forbidden-ext-indirect-access-own-prop-caller-value.js
new file mode 100644
index 0000000000..60f13fe355
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-func-expr-forbidden-ext-indirect-access-own-prop-caller-value.js
@@ -0,0 +1,65 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/forbidden-ext-indirect-access-own-prop-caller-value.case
+// - src/function-forms/forbidden-extensions/bullet-two/async-gen-func-expr.template
+/*---
+description: Forbidden extension, o.caller (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    If an implementation extends any function object with an own property named "caller" the value of
+    that property, as observed using [[Get]] or [[GetOwnProperty]], must not be a strict function
+    object. If it is an accessor property, the function that is the value of the property's [[Get]]
+    attribute must never return a strict function when called.
+
+---*/
+var CALLER_OWN_PROPERTY_DOES_NOT_EXIST = Symbol();
+function inner() {
+  // This property may exist, but is forbidden from having a value that is a strict function object
+  return inner.hasOwnProperty("caller")
+    ? inner.caller
+    : CALLER_OWN_PROPERTY_DOES_NOT_EXIST;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*() {
+  "use strict";
+  // This and the following conditional value is set in the test's .case file.
+  // For every test that has a "true" value here, there is a
+  // corresponding test that has a "false" value here.
+  // They are generated from two different case files, which use
+  // the same templates.
+  let descriptor = Object.getOwnPropertyDescriptor(inner, "caller");
+  if (descriptor && descriptor.configurable && true) {
+    Object.defineProperty(inner, "caller", {value: 1});
+  }
+  var result = inner();
+  if (descriptor && descriptor.configurable && true) {
+    assert.sameValue(result, 1, 'If this test defined an own "caller" property on the inner function, then it should be accessible and should return the value it was set to.');
+  }
+  // "CALLER_OWN_PROPERTY_DOES_NOT_EXIST" is from
+  // forbidden-ext-indirect-access-prop-caller.case
+  //
+  // If the function object "inner" has an own property
+  // named "caller", then its value will be returned.
+  //
+  // If the function object "inner" DOES NOT have an
+  // own property named "caller", then the symbol
+  // CALLER_OWN_PROPERTY_DOES_NOT_EXIST will be returned.
+  if (result !== CALLER_OWN_PROPERTY_DOES_NOT_EXIST) {
+    assert.notSameValue(result, f);
+  }
+  callCount++;
+};
+
+f().next()
+  .then(() => {
+    assert.sameValue(callCount, 1, 'function body evaluated');
+  }, $DONE).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-func-expr-forbidden-ext-indirect-access-prop-caller.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-func-expr-forbidden-ext-indirect-access-prop-caller.js
new file mode 100644
index 0000000000..e15c292832
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-func-expr-forbidden-ext-indirect-access-prop-caller.js
@@ -0,0 +1,65 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/forbidden-ext-indirect-access-prop-caller.case
+// - src/function-forms/forbidden-extensions/bullet-two/async-gen-func-expr.template
+/*---
+description: Forbidden extension, o.caller (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    If an implementation extends any function object with an own property named "caller" the value of
+    that property, as observed using [[Get]] or [[GetOwnProperty]], must not be a strict function
+    object. If it is an accessor property, the function that is the value of the property's [[Get]]
+    attribute must never return a strict function when called.
+
+---*/
+var CALLER_OWN_PROPERTY_DOES_NOT_EXIST = Symbol();
+function inner() {
+  // This property may exist, but is forbidden from having a value that is a strict function object
+  return inner.hasOwnProperty("caller")
+    ? inner.caller
+    : CALLER_OWN_PROPERTY_DOES_NOT_EXIST;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*() {
+  "use strict";
+  // This and the following conditional value is set in the test's .case file.
+  // For every test that has a "true" value here, there is a
+  // corresponding test that has a "false" value here.
+  // They are generated from two different case files, which use
+  // the same templates.
+  let descriptor = Object.getOwnPropertyDescriptor(inner, "caller");
+  if (descriptor && descriptor.configurable && false) {
+    Object.defineProperty(inner, "caller", {});
+  }
+  var result = inner();
+  if (descriptor && descriptor.configurable && false) {
+    assert.sameValue(result, 1, 'If this test defined an own "caller" property on the inner function, then it should be accessible and should return the value it was set to.');
+  }
+  // "CALLER_OWN_PROPERTY_DOES_NOT_EXIST" is from
+  // forbidden-ext-indirect-access-prop-caller.case
+  //
+  // If the function object "inner" has an own property
+  // named "caller", then its value will be returned.
+  //
+  // If the function object "inner" DOES NOT have an
+  // own property named "caller", then the symbol
+  // CALLER_OWN_PROPERTY_DOES_NOT_EXIST will be returned.
+  if (result !== CALLER_OWN_PROPERTY_DOES_NOT_EXIST) {
+    assert.notSameValue(result, f);
+  }
+  callCount++;
+};
+
+f().next()
+  .then(() => {
+    assert.sameValue(callCount, 1, 'function body evaluated');
+  }, $DONE).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-named-func-expr-forbidden-ext-indirect-access-own-prop-caller-get.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-named-func-expr-forbidden-ext-indirect-access-own-prop-caller-get.js
new file mode 100644
index 0000000000..b033e2d359
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-named-func-expr-forbidden-ext-indirect-access-own-prop-caller-get.js
@@ -0,0 +1,65 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/forbidden-ext-indirect-access-own-prop-caller-get.case
+// - src/function-forms/forbidden-extensions/bullet-two/async-gen-named-func-expr.template
+/*---
+description: Forbidden extension, o.caller (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+
+    If an implementation extends any function object with an own property named "caller" the value of
+    that property, as observed using [[Get]] or [[GetOwnProperty]], must not be a strict function
+    object. If it is an accessor property, the function that is the value of the property's [[Get]]
+    attribute must never return a strict function when called.
+
+---*/
+var CALLER_OWN_PROPERTY_DOES_NOT_EXIST = Symbol();
+function inner() {
+  // This property may exist, but is forbidden from having a value that is a strict function object
+  return inner.hasOwnProperty("caller")
+    ? inner.caller
+    : CALLER_OWN_PROPERTY_DOES_NOT_EXIST;
+}
+
+
+var callCount = 0;
+var f;
+f = async function* g() {
+  "use strict";
+  // This and the following conditional value is set in the test's .case file.
+  // For every test that has a "true" value here, there is a
+  // corresponding test that has a "false" value here.
+  // They are generated from two different case files, which use
+  // the same templates.
+  let descriptor = Object.getOwnPropertyDescriptor(inner, "caller");
+  if (descriptor && descriptor.configurable && true) {
+    Object.defineProperty(inner, "caller", {get(){return 1}});
+  }
+  var result = inner();
+  if (descriptor && descriptor.configurable && true) {
+    assert.sameValue(result, 1, 'If this test defined an own "caller" property on the inner function, then it should be accessible and should return the value it was set to.');
+  }
+  // "CALLER_OWN_PROPERTY_DOES_NOT_EXIST" is from
+  // forbidden-ext-indirect-access-prop-caller.case
+  //
+  // If the function object "inner" has an own property
+  // named "caller", then its value will be returned.
+  //
+  // If the function object "inner" DOES NOT have an
+  // own property named "caller", then the symbol
+  // CALLER_OWN_PROPERTY_DOES_NOT_EXIST will be returned.
+  if (result !== CALLER_OWN_PROPERTY_DOES_NOT_EXIST) {
+    assert.notSameValue(result, f);
+  }
+  callCount++;
+};
+
+f().next()
+  .then(() => {
+    assert.sameValue(callCount, 1, 'function body evaluated');
+  }, $DONE).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-named-func-expr-forbidden-ext-indirect-access-own-prop-caller-value.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-named-func-expr-forbidden-ext-indirect-access-own-prop-caller-value.js
new file mode 100644
index 0000000000..fd99288e11
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-named-func-expr-forbidden-ext-indirect-access-own-prop-caller-value.js
@@ -0,0 +1,65 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/forbidden-ext-indirect-access-own-prop-caller-value.case
+// - src/function-forms/forbidden-extensions/bullet-two/async-gen-named-func-expr.template
+/*---
+description: Forbidden extension, o.caller (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+
+    If an implementation extends any function object with an own property named "caller" the value of
+    that property, as observed using [[Get]] or [[GetOwnProperty]], must not be a strict function
+    object. If it is an accessor property, the function that is the value of the property's [[Get]]
+    attribute must never return a strict function when called.
+
+---*/
+var CALLER_OWN_PROPERTY_DOES_NOT_EXIST = Symbol();
+function inner() {
+  // This property may exist, but is forbidden from having a value that is a strict function object
+  return inner.hasOwnProperty("caller")
+    ? inner.caller
+    : CALLER_OWN_PROPERTY_DOES_NOT_EXIST;
+}
+
+
+var callCount = 0;
+var f;
+f = async function* g() {
+  "use strict";
+  // This and the following conditional value is set in the test's .case file.
+  // For every test that has a "true" value here, there is a
+  // corresponding test that has a "false" value here.
+  // They are generated from two different case files, which use
+  // the same templates.
+  let descriptor = Object.getOwnPropertyDescriptor(inner, "caller");
+  if (descriptor && descriptor.configurable && true) {
+    Object.defineProperty(inner, "caller", {value: 1});
+  }
+  var result = inner();
+  if (descriptor && descriptor.configurable && true) {
+    assert.sameValue(result, 1, 'If this test defined an own "caller" property on the inner function, then it should be accessible and should return the value it was set to.');
+  }
+  // "CALLER_OWN_PROPERTY_DOES_NOT_EXIST" is from
+  // forbidden-ext-indirect-access-prop-caller.case
+  //
+  // If the function object "inner" has an own property
+  // named "caller", then its value will be returned.
+  //
+  // If the function object "inner" DOES NOT have an
+  // own property named "caller", then the symbol
+  // CALLER_OWN_PROPERTY_DOES_NOT_EXIST will be returned.
+  if (result !== CALLER_OWN_PROPERTY_DOES_NOT_EXIST) {
+    assert.notSameValue(result, f);
+  }
+  callCount++;
+};
+
+f().next()
+  .then(() => {
+    assert.sameValue(callCount, 1, 'function body evaluated');
+  }, $DONE).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-named-func-expr-forbidden-ext-indirect-access-prop-caller.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-named-func-expr-forbidden-ext-indirect-access-prop-caller.js
new file mode 100644
index 0000000000..24a7c4f53a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/async-gen-named-func-expr-forbidden-ext-indirect-access-prop-caller.js
@@ -0,0 +1,65 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/forbidden-ext-indirect-access-prop-caller.case
+// - src/function-forms/forbidden-extensions/bullet-two/async-gen-named-func-expr.template
+/*---
+description: Forbidden extension, o.caller (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+
+    If an implementation extends any function object with an own property named "caller" the value of
+    that property, as observed using [[Get]] or [[GetOwnProperty]], must not be a strict function
+    object. If it is an accessor property, the function that is the value of the property's [[Get]]
+    attribute must never return a strict function when called.
+
+---*/
+var CALLER_OWN_PROPERTY_DOES_NOT_EXIST = Symbol();
+function inner() {
+  // This property may exist, but is forbidden from having a value that is a strict function object
+  return inner.hasOwnProperty("caller")
+    ? inner.caller
+    : CALLER_OWN_PROPERTY_DOES_NOT_EXIST;
+}
+
+
+var callCount = 0;
+var f;
+f = async function* g() {
+  "use strict";
+  // This and the following conditional value is set in the test's .case file.
+  // For every test that has a "true" value here, there is a
+  // corresponding test that has a "false" value here.
+  // They are generated from two different case files, which use
+  // the same templates.
+  let descriptor = Object.getOwnPropertyDescriptor(inner, "caller");
+  if (descriptor && descriptor.configurable && false) {
+    Object.defineProperty(inner, "caller", {});
+  }
+  var result = inner();
+  if (descriptor && descriptor.configurable && false) {
+    assert.sameValue(result, 1, 'If this test defined an own "caller" property on the inner function, then it should be accessible and should return the value it was set to.');
+  }
+  // "CALLER_OWN_PROPERTY_DOES_NOT_EXIST" is from
+  // forbidden-ext-indirect-access-prop-caller.case
+  //
+  // If the function object "inner" has an own property
+  // named "caller", then its value will be returned.
+  //
+  // If the function object "inner" DOES NOT have an
+  // own property named "caller", then the symbol
+  // CALLER_OWN_PROPERTY_DOES_NOT_EXIST will be returned.
+  if (result !== CALLER_OWN_PROPERTY_DOES_NOT_EXIST) {
+    assert.notSameValue(result, f);
+  }
+  callCount++;
+};
+
+f().next()
+  .then(() => {
+    assert.sameValue(callCount, 1, 'function body evaluated');
+  }, $DONE).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/browser.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/browser.js
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/shell.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/b2/shell.js
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/browser.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/browser.js
diff --git a/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/shell.js b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/forbidden-ext/shell.js
diff --git a/js/src/tests/test262/language/expressions/async-generator/generator-created-after-decl-inst.js b/js/src/tests/test262/language/expressions/async-generator/generator-created-after-decl-inst.js
new file mode 100644
index 0000000000..9d74e66534
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/generator-created-after-decl-inst.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2018 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-asyncgenerator-definitions-evaluatebody
+description: >
+    The generator object is created after FunctionDeclarationInstantiation.
+info: |
+    14.5.10 Runtime Semantics: EvaluateBody
+
+    1. Perform ? FunctionDeclarationInstantiation(functionObject, argumentsList).
+    2. Let generator be ? OrdinaryCreateFromConstructor(functionObject, "%AsyncGeneratorPrototype%",
+       « [[AsyncGeneratorState]], [[AsyncGeneratorContext]], [[AsyncGeneratorQueue]] »).
+    3. Perform ! AsyncGeneratorStart(generator, FunctionBody).
+    ...
+
+features: [async-iteration]
+---*/
+
+var g = async function*(a = (g.prototype = null)) {}
+var oldPrototype = g.prototype;
+var it = g();
+
+assert.notSameValue(Object.getPrototypeOf(it), oldPrototype);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/name.js b/js/src/tests/test262/language/expressions/async-generator/name.js
new file mode 100644
index 0000000000..4dfd2d458d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/name.js
@@ -0,0 +1,38 @@
+// Copyright (C) 2019 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-asyncgenerator-definitions-evaluation
+description: Assignment of function `name` attribute
+info: |
+    AsyncGeneratorExpression : async function * ( FormalParameters ) { AsyncGeneratorBody }
+
+    1. Let scope be the LexicalEnvironment of the running execution context.
+    2. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+       AsyncGeneratorBody, scope, "").
+    ...
+    6. Return closure.
+
+    AsyncGeneratorExpression : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+    1. Let scope be the running execution context's LexicalEnvironment.
+    2. Let funcEnv be ! NewDeclarativeEnvironment(scope).
+    3. Let envRec be funcEnv's EnvironmentRecord.
+    4. Let name be StringValue of BindingIdentifier.
+    5. Perform ! envRec.CreateImmutableBinding(name).
+    6. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+       AsyncGeneratorBody, funcEnv, name).
+    ...
+    11. Return closure.
+includes: [propertyHelper.js]
+---*/
+
+verifyProperty(async function*() {}, "name", {
+  value: "", writable: false, enumerable: false, configurable: true
+});
+
+verifyProperty(async function* func() {}, "name", {
+  value: "func", writable: false, enumerable: false, configurable: true
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-array-destructuring-param-strict-body.js b/js/src/tests/test262/language/expressions/async-generator/named-array-destructuring-param-strict-body.js
new file mode 100644
index 0000000000..55d242fd7b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-array-destructuring-param-strict-body.js
@@ -0,0 +1,113 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/array-destructuring-param-strict-body.case
+// - src/function-forms/syntax/async-gen-named-func-expr.template
+/*---
+description: ArrayBindingPattern and Use Strict Directive are not allowed to coexist for the same function. (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [rest-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.4 Static Semantics: IsSimpleParameterList
+
+    BindingElement : BindingPattern
+
+    1. Return false.
+
+    14.1.2 Static Semantics: Early Errors
+
+    FunctionDeclaration : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+    FunctionDeclaration : function ( FormalParameters ) { FunctionBody }
+    FunctionExpression : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.2.1 Static Semantics: Early Errors
+
+    ArrowFunction : ArrowParameters => ConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of ConciseBody is true and
+      IsSimpleParameterList of ArrowParameters is false.
+
+    14.3.1 Static Semantics: Early Errors
+
+    MethodDefinition : PropertyName ( UniqueFormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    MethodDefinition : set PropertyName ( PropertySetParameterList ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of PropertySetParameterList is false.
+
+    14.4.1 Static Semantics: Early Errors
+
+    GeneratorMethod : * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    GeneratorDeclaration : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+    GeneratorDeclaration : function * ( FormalParameters ) { GeneratorBody }
+    GeneratorExpression : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    14.5.1 Static Semantics: Early Errors
+
+    AsyncGeneratorMethod : async * PropertyName ( UniqueFormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncGeneratorDeclaration : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorDeclaration : async function * ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorExpression : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.7.1 Static Semantics: Early Errors
+
+    AsyncMethod : async PropertyName ( UniqueFormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncFunctionDeclaration : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionDeclaration : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.8.1 Static Semantics: Early Errors
+
+    AsyncArrowFunction : CoverCallExpressionAndAsyncArrowHead => AsyncConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncConciseBody is true and
+      IsSimpleParameterList of CoverCallExpressionAndAsyncArrowHead is false.
+
+---*/
+$DONOTEVALUATE();
+
+
+0, async function* g([element]) {
+  "use strict";
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-await-as-binding-identifier-escaped.js b/js/src/tests/test262/language/expressions/async-generator/named-await-as-binding-identifier-escaped.js
new file mode 100644
index 0000000000..4653cf575e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-await-as-binding-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-binding-identifier-escaped.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  var \u0061wait;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-await-as-binding-identifier.js b/js/src/tests/test262/language/expressions/async-generator/named-await-as-binding-identifier.js
new file mode 100644
index 0000000000..cac883210c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-await-as-binding-identifier.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-binding-identifier.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  var await;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-await-as-identifier-reference-escaped.js b/js/src/tests/test262/language/expressions/async-generator/named-await-as-identifier-reference-escaped.js
new file mode 100644
index 0000000000..b4d9f6e00e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-await-as-identifier-reference-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-identifier-reference-escaped.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  void \u0061wait;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-await-as-identifier-reference.js b/js/src/tests/test262/language/expressions/async-generator/named-await-as-identifier-reference.js
new file mode 100644
index 0000000000..ebc00efaae
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-await-as-identifier-reference.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-identifier-reference.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  void await;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-await-as-label-identifier-escaped.js b/js/src/tests/test262/language/expressions/async-generator/named-await-as-label-identifier-escaped.js
new file mode 100644
index 0000000000..e15ea1760c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-await-as-label-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-label-identifier-escaped.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a label identifier. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  \u0061wait: ;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-await-as-label-identifier.js b/js/src/tests/test262/language/expressions/async-generator/named-await-as-label-identifier.js
new file mode 100644
index 0000000000..d189f17d06
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-await-as-label-identifier.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-label-identifier.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a label identifier. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  await: ;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-abrupt.js
new file mode 100644
index 0000000000..d3c1e3b4a2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-abrupt.js
@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-abrupt.case
+// - src/function-forms/error/async-gen-named-func-expr.template
+/*---
+description: Abrupt completion returned by evaluation of initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* g(_ = (function() { throw new Test262Error(); }())) {
+  
+  callCount = callCount + 1;
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+assert.sameValue(callCount, 0, 'generator function body not evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-arg-val-not-undefined.js b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-arg-val-not-undefined.js
new file mode 100644
index 0000000000..9599a09907
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-arg-val-not-undefined.js
@@ -0,0 +1,66 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-arg-val-not-undefined.case
+// - src/function-forms/default/async-gen-named-func-expr.template
+/*---
+description: Use of initializer when argument value is not `undefined` (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    [...]
+    23. Let iteratorRecord be Record {[[Iterator]]:
+        CreateListIterator(argumentsList), [[Done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        a. Perform ? IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+---*/
+var obj = {};
+var falseCount = 0;
+var stringCount = 0;
+var nanCount = 0;
+var zeroCount = 0;
+var nullCount = 0;
+var objCount = 0;
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function* g(aFalse = falseCount +=1, aString = stringCount += 1, aNaN = nanCount += 1, a0 = zeroCount += 1, aNull = nullCount += 1, aObj = objCount +=1) {
+  assert.sameValue(aFalse, false);
+  assert.sameValue(aString, '');
+  assert.sameValue(aNaN, NaN);
+  assert.sameValue(a0, 0);
+  assert.sameValue(aNull, null);
+  assert.sameValue(aObj, obj);
+  callCount = callCount + 1;
+};
+
+ref(false, '', NaN, 0, null, obj).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+assert.sameValue(falseCount, 0, 'initializer not evaluated: false');
+assert.sameValue(stringCount, 0, 'initializer not evaluated: string');
+assert.sameValue(nanCount, 0, 'initializer not evaluated: NaN');
+assert.sameValue(zeroCount, 0, 'initializer not evaluated: 0');
+assert.sameValue(nullCount, 0, 'initializer not evaluated: null');
+assert.sameValue(objCount, 0, 'initializer not evaluated: object');
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-arg-val-undefined.js b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-arg-val-undefined.js
new file mode 100644
index 0000000000..a1822f2d5a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-arg-val-undefined.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-arg-val-undefined.case
+// - src/function-forms/default/async-gen-named-func-expr.template
+/*---
+description: Use of initializer when argument value is `undefined` (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    [...]
+    23. Let iteratorRecord be Record {[[Iterator]]:
+        CreateListIterator(argumentsList), [[Done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        a. Perform ? IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+---*/
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function* g(fromLiteral = 23, fromExpr = 45, fromHole = 99) {
+  assert.sameValue(fromLiteral, 23);
+  assert.sameValue(fromExpr, 45);
+  assert.sameValue(fromHole, 99);
+  callCount = callCount + 1;
+};
+
+ref(undefined, void 0).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-duplicates.js b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-duplicates.js
new file mode 100644
index 0000000000..9fd77d7680
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-duplicates.js
@@ -0,0 +1,42 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-duplicates.case
+// - src/function-forms/syntax/async-gen-named-func-expr.template
+/*---
+description: It is a Syntax Error if BoundNames of FormalParameters contains any duplicate elements. (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    14.1.2 Static Semantics: Early Errors
+
+    StrictFormalParameters : FormalParameters
+
+    - It is a Syntax Error if BoundNames of FormalParameters contains any
+      duplicate elements.
+
+    FormalParameters : FormalParameterList
+
+    - It is a Syntax Error if IsSimpleParameterList of FormalParameterList is
+      false and BoundNames of FormalParameterList contains any duplicate
+      elements.
+
+---*/
+$DONOTEVALUATE();
+
+
+0, async function* g(x = 0, x) {
+  
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-ref-later.js b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-ref-later.js
new file mode 100644
index 0000000000..a57df156aa
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-ref-later.js
@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-ref-later.case
+// - src/function-forms/error/async-gen-named-func-expr.template
+/*---
+description: Referencing a parameter that occurs later in the ParameterList (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+var x = 0;
+
+
+var callCount = 0;
+var f;
+f = async function* g(x = y, y) {
+  
+  callCount = callCount + 1;
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+assert.sameValue(callCount, 0, 'generator function body not evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-ref-prior.js b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-ref-prior.js
new file mode 100644
index 0000000000..6b23c62f38
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-ref-prior.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-ref-prior.case
+// - src/function-forms/default/async-gen-named-func-expr.template
+/*---
+description: Referencing a parameter that occurs earlier in the ParameterList (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+var x = 0;
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function* g(x, y = x, z = y) {
+  assert.sameValue(x, 3, 'first argument value');
+  assert.sameValue(y, 3, 'second argument value');
+  assert.sameValue(z, 3, 'third argument value');
+  callCount = callCount + 1;
+};
+
+ref(3).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-ref-self.js b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-ref-self.js
new file mode 100644
index 0000000000..06abd430c8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-ref-self.js
@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-ref-self.case
+// - src/function-forms/error/async-gen-named-func-expr.template
+/*---
+description: Referencing a parameter from within its own initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+var x = 0;
+
+
+var callCount = 0;
+var f;
+f = async function* g(x = x) {
+  
+  callCount = callCount + 1;
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+assert.sameValue(callCount, 0, 'generator function body not evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-rest.js b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-rest.js
new file mode 100644
index 0000000000..67e8ee7e84
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-rest.js
@@ -0,0 +1,46 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-rest.case
+// - src/function-forms/syntax/async-gen-named-func-expr.template
+/*---
+description: RestParameter does not support an initializer (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    14.1 Function Definitions
+
+    Syntax
+
+    FunctionRestParameter[Yield] :
+
+      BindingRestElement[?Yield]
+
+    13.3.3 Destructuring Binding Patterns
+
+    Syntax
+
+    BindingRestElement[Yield] :
+
+      ...BindingIdentifier[?Yield]
+      ...BindingPattern[?Yield]
+
+---*/
+$DONOTEVALUATE();
+
+
+0, async function* g(...x = []) {
+  
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-trailing-comma.js b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-trailing-comma.js
new file mode 100644
index 0000000000..7697a9613b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-dflt-params-trailing-comma.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-trailing-comma.case
+// - src/function-forms/default/async-gen-named-func-expr.template
+/*---
+description: A trailing comma should not increase the respective length, using default parameters (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] : FormalParameterList[?Yield, ?Await] ,
+---*/
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function* g(a, b = 39,) {
+  assert.sameValue(a, 42);
+  assert.sameValue(b, 39);
+  callCount = callCount + 1;
+};
+
+ref(42, undefined, 1).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+assert.sameValue(ref.length, 1, 'length is properly set');
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-eval-var-scope-syntax-err.js b/js/src/tests/test262/language/expressions/async-generator/named-eval-var-scope-syntax-err.js
new file mode 100644
index 0000000000..1f80e5ff9d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-eval-var-scope-syntax-err.js
@@ -0,0 +1,40 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/eval-var-scope-syntax-err.case
+// - src/function-forms/error-no-strict/async-gen-named-func-expr.template
+/*---
+description: sloppy direct eval in params introduces var (async generator named function expression in sloppy code)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [default-parameters, async-iteration]
+flags: [generated, noStrict]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    
+    Runtime Semantics: IteratorBindingInitialization
+    FormalParameter : BindingElement
+
+    1. Return the result of performing IteratorBindingInitialization for BindingElement with arguments iteratorRecord and environment.
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function* g(a = eval("var a = 42")) {
+  
+  callCount = callCount + 1;
+};
+
+assert.throws(SyntaxError, function() {
+  f();
+});
+assert.sameValue(callCount, 0, 'generator function body not evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-no-strict-reassign-fn-name-in-body-in-arrow.js b/js/src/tests/test262/language/expressions/async-generator/named-no-strict-reassign-fn-name-in-body-in-arrow.js
new file mode 100644
index 0000000000..27c70d438a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-no-strict-reassign-fn-name-in-body-in-arrow.js
@@ -0,0 +1,31 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/reassign-fn-name-in-body-in-arrow.case
+// - src/function-forms/expr-named/async-gen-func-expr-named-no-strict.template
+/*---
+description: Reassignment of function name is silently ignored in non-strict mode code. (async generator named function expression in non-strict mode code)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async, noStrict]
+includes: [asyncHelpers.js]
+info: |
+    AsyncGeneratorExpression :
+        async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+---*/
+
+// increment callCount in case "body"
+let callCount = 0;
+let ref = async function * BindingIdentifier() {
+  callCount++;
+  (() => {
+    BindingIdentifier = 1;
+  })();
+  return BindingIdentifier;
+};
+
+asyncTest(async () => {
+  assert.sameValue((await (await ref()).next()).value, ref);
+  assert.sameValue(callCount, 1, 'function invoked exactly once');
+});
+
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-no-strict-reassign-fn-name-in-body-in-eval.js b/js/src/tests/test262/language/expressions/async-generator/named-no-strict-reassign-fn-name-in-body-in-eval.js
new file mode 100644
index 0000000000..f707a29d64
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-no-strict-reassign-fn-name-in-body-in-eval.js
@@ -0,0 +1,29 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/reassign-fn-name-in-body-in-eval.case
+// - src/function-forms/expr-named/async-gen-func-expr-named-no-strict.template
+/*---
+description: Reassignment of function name is silently ignored in non-strict mode code. (async generator named function expression in non-strict mode code)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async, noStrict]
+includes: [asyncHelpers.js]
+info: |
+    AsyncGeneratorExpression :
+        async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+---*/
+
+// increment callCount in case "body"
+let callCount = 0;
+let ref = async function * BindingIdentifier() {
+  callCount++;
+  eval("BindingIdentifier = 1");
+  return BindingIdentifier;
+};
+
+asyncTest(async () => {
+  assert.sameValue((await (await ref()).next()).value, ref);
+  assert.sameValue(callCount, 1, 'function invoked exactly once');
+});
+
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-no-strict-reassign-fn-name-in-body.js b/js/src/tests/test262/language/expressions/async-generator/named-no-strict-reassign-fn-name-in-body.js
new file mode 100644
index 0000000000..2d5733f65a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-no-strict-reassign-fn-name-in-body.js
@@ -0,0 +1,29 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/reassign-fn-name-in-body.case
+// - src/function-forms/expr-named/async-gen-func-expr-named-no-strict.template
+/*---
+description: Reassignment of function name is silently ignored in non-strict mode code. (async generator named function expression in non-strict mode code)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async, noStrict]
+includes: [asyncHelpers.js]
+info: |
+    AsyncGeneratorExpression :
+        async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+---*/
+
+// increment callCount in case "body"
+let callCount = 0;
+let ref = async function * BindingIdentifier() {
+  callCount++;
+  BindingIdentifier = 1;
+  return BindingIdentifier;
+};
+
+asyncTest(async () => {
+  assert.sameValue((await (await ref()).next()).value, ref);
+  assert.sameValue(callCount, 1, 'function invoked exactly once');
+});
+
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-object-destructuring-param-strict-body.js b/js/src/tests/test262/language/expressions/async-generator/named-object-destructuring-param-strict-body.js
new file mode 100644
index 0000000000..1b6d5ef9dd
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-object-destructuring-param-strict-body.js
@@ -0,0 +1,113 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/object-destructuring-param-strict-body.case
+// - src/function-forms/syntax/async-gen-named-func-expr.template
+/*---
+description: ObjectBindingPattern and Use Strict Directive are not allowed to coexist for the same function. (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [rest-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    13.3.3.4 Static Semantics: IsSimpleParameterList
+
+    BindingElement : BindingPattern
+
+    1. Return false.
+
+    14.1.2 Static Semantics: Early Errors
+
+    FunctionDeclaration : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+    FunctionDeclaration : function ( FormalParameters ) { FunctionBody }
+    FunctionExpression : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.2.1 Static Semantics: Early Errors
+
+    ArrowFunction : ArrowParameters => ConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of ConciseBody is true and
+      IsSimpleParameterList of ArrowParameters is false.
+
+    14.3.1 Static Semantics: Early Errors
+
+    MethodDefinition : PropertyName ( UniqueFormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    MethodDefinition : set PropertyName ( PropertySetParameterList ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of PropertySetParameterList is false.
+
+    14.4.1 Static Semantics: Early Errors
+
+    GeneratorMethod : * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    GeneratorDeclaration : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+    GeneratorDeclaration : function * ( FormalParameters ) { GeneratorBody }
+    GeneratorExpression : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    14.5.1 Static Semantics: Early Errors
+
+    AsyncGeneratorMethod : async * PropertyName ( UniqueFormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncGeneratorDeclaration : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorDeclaration : async function * ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorExpression : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.7.1 Static Semantics: Early Errors
+
+    AsyncMethod : async PropertyName ( UniqueFormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncFunctionDeclaration : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionDeclaration : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.8.1 Static Semantics: Early Errors
+
+    AsyncArrowFunction : CoverCallExpressionAndAsyncArrowHead => AsyncConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncConciseBody is true and
+      IsSimpleParameterList of CoverCallExpressionAndAsyncArrowHead is false.
+
+---*/
+$DONOTEVALUATE();
+
+
+0, async function* g({property}) {
+  "use strict";
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-params-trailing-comma-multiple.js b/js/src/tests/test262/language/expressions/async-generator/named-params-trailing-comma-multiple.js
new file mode 100644
index 0000000000..2206c44438
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-params-trailing-comma-multiple.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/params-trailing-comma-multiple.case
+// - src/function-forms/default/async-gen-named-func-expr.template
+/*---
+description: A trailing comma should not increase the respective length, using multiple parameters (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] : FormalParameterList[?Yield, ?Await] ,
+---*/
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function* g(a, b,) {
+  assert.sameValue(a, 42);
+  assert.sameValue(b, 39);
+  callCount = callCount + 1;
+};
+
+ref(42, 39, 1).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+assert.sameValue(ref.length, 2, 'length is properly set');
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-params-trailing-comma-single.js b/js/src/tests/test262/language/expressions/async-generator/named-params-trailing-comma-single.js
new file mode 100644
index 0000000000..30f73b4433
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-params-trailing-comma-single.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/params-trailing-comma-single.case
+// - src/function-forms/default/async-gen-named-func-expr.template
+/*---
+description: A trailing comma should not increase the respective length, using a single parameter (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] : FormalParameterList[?Yield, ?Await] ,
+---*/
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function* g(a,) {
+  assert.sameValue(a, 42);
+  callCount = callCount + 1;
+};
+
+ref(42, 39).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+assert.sameValue(ref.length, 1, 'length is properly set');
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-rest-param-strict-body.js b/js/src/tests/test262/language/expressions/async-generator/named-rest-param-strict-body.js
new file mode 100644
index 0000000000..11675d2870
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-rest-param-strict-body.js
@@ -0,0 +1,113 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/rest-param-strict-body.case
+// - src/function-forms/syntax/async-gen-named-func-expr.template
+/*---
+description: RestParameter and Use Strict Directive are not allowed to coexist for the same function. (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [rest-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    14.1.13 Static Semantics: IsSimpleParameterList
+
+    FormalParameters : FormalParameterList , FunctionRestParameter
+
+    1. Return false.
+
+    14.1.2 Static Semantics: Early Errors
+
+    FunctionDeclaration : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+    FunctionDeclaration : function ( FormalParameters ) { FunctionBody }
+    FunctionExpression : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.2.1 Static Semantics: Early Errors
+
+    ArrowFunction : ArrowParameters => ConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of ConciseBody is true and
+      IsSimpleParameterList of ArrowParameters is false.
+
+    14.3.1 Static Semantics: Early Errors
+
+    MethodDefinition : PropertyName ( UniqueFormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    MethodDefinition : set PropertyName ( PropertySetParameterList ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of PropertySetParameterList is false.
+
+    14.4.1 Static Semantics: Early Errors
+
+    GeneratorMethod : * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    GeneratorDeclaration : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+    GeneratorDeclaration : function * ( FormalParameters ) { GeneratorBody }
+    GeneratorExpression : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    14.5.1 Static Semantics: Early Errors
+
+    AsyncGeneratorMethod : async * PropertyName ( UniqueFormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncGeneratorDeclaration : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorDeclaration : async function * ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorExpression : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.7.1 Static Semantics: Early Errors
+
+    AsyncMethod : async PropertyName ( UniqueFormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncFunctionDeclaration : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionDeclaration : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.8.1 Static Semantics: Early Errors
+
+    AsyncArrowFunction : CoverCallExpressionAndAsyncArrowHead => AsyncConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncConciseBody is true and
+      IsSimpleParameterList of CoverCallExpressionAndAsyncArrowHead is false.
+
+---*/
+$DONOTEVALUATE();
+
+
+0, async function* g(a,...rest) {
+  "use strict";
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-rest-params-trailing-comma-early-error.js b/js/src/tests/test262/language/expressions/async-generator/named-rest-params-trailing-comma-early-error.js
new file mode 100644
index 0000000000..1c760b6354
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-rest-params-trailing-comma-early-error.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/rest-params-trailing-comma-early-error.case
+// - src/function-forms/syntax/async-gen-named-func-expr.template
+/*---
+description: It's a syntax error if a FunctionRestParameter is followed by a trailing comma (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] :
+        [empty]
+        FunctionRestParameter[?Yield, ?Await]
+        FormalParameterList[?Yield, ?Await]
+        FormalParameterList[?Yield, ?Await] ,
+        FormalParameterList[?Yield, ?Await] , FunctionRestParameter[?Yield, ?Await]
+---*/
+$DONOTEVALUATE();
+
+
+0, async function* g(...a,) {
+  
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-strict-error-reassign-fn-name-in-body-in-arrow-strict.js b/js/src/tests/test262/language/expressions/async-generator/named-strict-error-reassign-fn-name-in-body-in-arrow-strict.js
new file mode 100644
index 0000000000..edadb9d94a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-strict-error-reassign-fn-name-in-body-in-arrow-strict.js
@@ -0,0 +1,39 @@
+// |reftest| async
+'use strict';
+// This file was procedurally generated from the following sources:
+// - src/function-forms/reassign-fn-name-in-body-in-arrow.case
+// - src/function-forms/expr-named/async-gen-func-expr-named-strict-error.template
+/*---
+description: Reassignment of function name is silently ignored in non-strict mode code. (async generator named function expression in strict mode code)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async, onlyStrict]
+includes: [asyncHelpers.js]
+info: |
+    AsyncGeneratorExpression :
+        async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+---*/
+
+// increment callCount in case "body"
+let callCount = 0;
+let ref = async function * BindingIdentifier() {
+  callCount++;
+  (() => {
+    BindingIdentifier = 1;
+  })();
+  return BindingIdentifier;
+};
+
+asyncTest(async () => {
+  let catchCount = 0;
+  try {
+    (await (await ref()).next()).value
+  } catch (error) {
+    catchCount++;
+    assert(error instanceof TypeError);
+  }
+  assert.sameValue(catchCount, 1);
+  assert.sameValue(callCount, 1);
+});
+
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-strict-error-reassign-fn-name-in-body-in-eval-strict.js b/js/src/tests/test262/language/expressions/async-generator/named-strict-error-reassign-fn-name-in-body-in-eval-strict.js
new file mode 100644
index 0000000000..f59feecf43
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-strict-error-reassign-fn-name-in-body-in-eval-strict.js
@@ -0,0 +1,37 @@
+// |reftest| async
+'use strict';
+// This file was procedurally generated from the following sources:
+// - src/function-forms/reassign-fn-name-in-body-in-eval.case
+// - src/function-forms/expr-named/async-gen-func-expr-named-strict-error.template
+/*---
+description: Reassignment of function name is silently ignored in non-strict mode code. (async generator named function expression in strict mode code)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async, onlyStrict]
+includes: [asyncHelpers.js]
+info: |
+    AsyncGeneratorExpression :
+        async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+---*/
+
+// increment callCount in case "body"
+let callCount = 0;
+let ref = async function * BindingIdentifier() {
+  callCount++;
+  eval("BindingIdentifier = 1");
+  return BindingIdentifier;
+};
+
+asyncTest(async () => {
+  let catchCount = 0;
+  try {
+    (await (await ref()).next()).value
+  } catch (error) {
+    catchCount++;
+    assert(error instanceof TypeError);
+  }
+  assert.sameValue(catchCount, 1);
+  assert.sameValue(callCount, 1);
+});
+
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-strict-error-reassign-fn-name-in-body-strict.js b/js/src/tests/test262/language/expressions/async-generator/named-strict-error-reassign-fn-name-in-body-strict.js
new file mode 100644
index 0000000000..0a2df195c8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-strict-error-reassign-fn-name-in-body-strict.js
@@ -0,0 +1,37 @@
+// |reftest| async
+'use strict';
+// This file was procedurally generated from the following sources:
+// - src/function-forms/reassign-fn-name-in-body.case
+// - src/function-forms/expr-named/async-gen-func-expr-named-strict-error.template
+/*---
+description: Reassignment of function name is silently ignored in non-strict mode code. (async generator named function expression in strict mode code)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async, onlyStrict]
+includes: [asyncHelpers.js]
+info: |
+    AsyncGeneratorExpression :
+        async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+---*/
+
+// increment callCount in case "body"
+let callCount = 0;
+let ref = async function * BindingIdentifier() {
+  callCount++;
+  BindingIdentifier = 1;
+  return BindingIdentifier;
+};
+
+asyncTest(async () => {
+  let catchCount = 0;
+  try {
+    (await (await ref()).next()).value
+  } catch (error) {
+    catchCount++;
+    assert(error instanceof TypeError);
+  }
+  assert.sameValue(catchCount, 1);
+  assert.sameValue(callCount, 1);
+});
+
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-unscopables-with-in-nested-fn.js b/js/src/tests/test262/language/expressions/async-generator/named-unscopables-with-in-nested-fn.js
new file mode 100644
index 0000000000..f32c2a08de
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-unscopables-with-in-nested-fn.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/unscopables-with-in-nested-fn.case
+// - src/function-forms/default/async-gen-named-func-expr.template
+/*---
+description: Symbol.unscopables behavior across scope boundaries (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [globalThis, Symbol.unscopables, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    ...
+    Let envRec be lex's EnvironmentRecord.
+    Let exists be ? envRec.HasBinding(name).
+
+    HasBinding
+
+    ...
+    If the withEnvironment flag of envRec is false, return true.
+    Let unscopables be ? Get(bindings, @@unscopables).
+    If Type(unscopables) is Object, then
+       Let blocked be ToBoolean(? Get(unscopables, N)).
+       If blocked is true, return false.
+
+    (The `with` Statement) Runtime Semantics: Evaluation
+
+    ...
+    Set the withEnvironment flag of newEnv’s EnvironmentRecord to true.
+    ...
+
+---*/
+let count = 0;
+var v = 1;
+globalThis[Symbol.unscopables] = {
+  v: true,
+};
+
+{
+  count++;
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function* g(x) {
+  (function() {
+    count++;
+    with (globalThis) {
+      count++;
+      assert.sameValue(v, 1, 'The value of `v` is 1');
+    }
+  })();
+  (function() {
+    count++;
+    var v = x;
+    with (globalThis) {
+      count++;
+      assert.sameValue(v, 10, 'The value of `v` is 10');
+      v = 20;
+    }
+    assert.sameValue(v, 20, 'The value of `v` is 20');
+    assert.sameValue(globalThis.v, 1, 'The value of globalThis.v is 1');
+  })();
+  assert.sameValue(v, 1, 'The value of `v` is 1');
+  assert.sameValue(globalThis.v, 1, 'The value of globalThis.v is 1');
+  callCount = callCount + 1;
+};
+
+ref(10).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+  count++;
+}
+assert.sameValue(count, 6, 'The value of `count` is 6');
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-unscopables-with.js b/js/src/tests/test262/language/expressions/async-generator/named-unscopables-with.js
new file mode 100644
index 0000000000..1656b3cbc6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-unscopables-with.js
@@ -0,0 +1,77 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/unscopables-with.case
+// - src/function-forms/default/async-gen-named-func-expr.template
+/*---
+description: Symbol.unscopables behavior across scope boundaries (async generator named function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [globalThis, Symbol.unscopables, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        7. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, funcEnv, strict).
+        [...]
+
+
+    ...
+    Let envRec be lex's EnvironmentRecord.
+    Let exists be ? envRec.HasBinding(name).
+
+    HasBinding
+
+    ...
+    If the withEnvironment flag of envRec is false, return true.
+    Let unscopables be ? Get(bindings, @@unscopables).
+    If Type(unscopables) is Object, then
+       Let blocked be ToBoolean(? Get(unscopables, N)).
+       If blocked is true, return false.
+
+    (The `with` Statement) Runtime Semantics: Evaluation
+
+    ...
+    Set the withEnvironment flag of newEnv’s EnvironmentRecord to true.
+    ...
+
+---*/
+let count = 0;
+var v = 1;
+globalThis[Symbol.unscopables] = {
+  v: true,
+};
+
+{
+  count++;
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function* g(x) {
+  count++;
+  with (globalThis) {
+    count++;
+    assert.sameValue(v, undefined, 'The value of `v` is expected to equal `undefined`');
+  }
+  count++;
+  var v = x;
+  with (globalThis) {
+    count++;
+    assert.sameValue(v, 10, 'The value of `v` is 10');
+    v = 20;
+  }
+  assert.sameValue(v, 20, 'The value of `v` is 20');
+  assert.sameValue(globalThis.v, 1, 'The value of globalThis.v is 1');
+  callCount = callCount + 1;
+};
+
+ref(10).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+  count++;
+}
+assert.sameValue(count, 6, 'The value of `count` is 6');
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-as-binding-identifier-escaped.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-binding-identifier-escaped.js
new file mode 100644
index 0000000000..bc6d428325
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-binding-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-binding-identifier-escaped.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  var yi\u0065ld;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-as-binding-identifier.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-binding-identifier.js
new file mode 100644
index 0000000000..7c1f9011cc
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-binding-identifier.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-binding-identifier.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  var yield;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-as-identifier-reference-escaped.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-identifier-reference-escaped.js
new file mode 100644
index 0000000000..a91e7d984d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-identifier-reference-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-identifier-reference-escaped.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  void yi\u0065ld;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-as-identifier-reference.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-identifier-reference.js
new file mode 100644
index 0000000000..9e03c21bca
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-identifier-reference.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-identifier-reference.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  void yield;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-as-label-identifier-escaped.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-label-identifier-escaped.js
new file mode 100644
index 0000000000..77e30f2030
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-label-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-label-identifier-escaped.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a label identifier. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  yi\u0065ld: ;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-as-label-identifier.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-label-identifier.js
new file mode 100644
index 0000000000..b4acf9c3b1
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-as-label-identifier.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-label-identifier.case
+// - src/async-generators/syntax/async-expression-named.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a label identifier. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *g() {
+  yield: ;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-non-strict.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-non-strict.js
new file mode 100644
index 0000000000..ac8b2ffa0e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-non-strict.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-identifier-non-strict.case
+// - src/async-generators/non-strict/async-expression-named.template
+/*---
+description: Use of yield as a valid identifier in a function body inside a generator body in non strict mode (Async generator named expression - valid for non-strict only cases)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  return (function(arg) {
+      var yield = arg + 1;
+      return yield;
+    }(yield))
+};
+
+var iter = gen();
+
+var item = iter.next();
+
+item.then(({ done, value }) => {
+  assert.sameValue(done, false);
+  assert.sameValue(value, undefined);
+});
+
+item = iter.next(42);
+
+item.then(({ done, value }) => {
+  assert.sameValue(done, true);
+  assert.sameValue(value, 43);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-spread-non-strict.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-spread-non-strict.js
new file mode 100644
index 0000000000..89894af883
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-spread-non-strict.js
@@ -0,0 +1,64 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-identifier-spread-non-strict.case
+// - src/async-generators/non-strict/async-expression-named.template
+/*---
+description: Mixed use of object spread and yield as a valid identifier in a function body inside a generator body in non strict mode (Async generator named expression - valid for non-strict only cases)
+esid: prod-AsyncGeneratorExpression
+features: [object-spread, Symbol, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Spread Properties
+
+    PropertyDefinition[Yield]:
+      (...)
+      ...AssignmentExpression[In, ?Yield]
+
+---*/
+var s = Symbol('s');
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield {
+       ...yield yield,
+       ...(function(arg) {
+          var yield = arg;
+          return {...yield};
+       }(yield)),
+       ...yield,
+    }
+};
+
+var iter = gen();
+
+var iter = gen();
+
+iter.next();
+iter.next();
+iter.next({ x: 10, a: 0, b: 0, [s]: 1 });
+iter.next({ y: 20, a: 1, b: 1, [s]: 42 });
+var item = iter.next({ z: 30, b: 2 });
+
+item.then(({ done, value }) => {
+  assert.sameValue(done, false);
+  assert.sameValue(value.x, 10);
+  assert.sameValue(value.y, 20);
+  assert.sameValue(value.z, 30);
+  assert.sameValue(value.a, 1);
+  assert.sameValue(value.b, 2);
+  assert.sameValue(value[s], 42);
+  assert.sameValue(Object.keys(value).length, 5);
+  assert(Object.prototype.hasOwnProperty.call(value, s), "s is an own property");
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-spread-strict-strict.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-spread-strict-strict.js
new file mode 100644
index 0000000000..1a05d4e18c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-spread-strict-strict.js
@@ -0,0 +1,48 @@
+// |reftest| error:SyntaxError
+'use strict';
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-identifier-spread-strict.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: It's an early error if the AssignmentExpression is a function body with yield as an identifier in strict mode. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [object-spread, async-iteration]
+flags: [generated, onlyStrict]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Spread Properties
+
+    PropertyDefinition[Yield]:
+      (...)
+      ...AssignmentExpression[In, ?Yield]
+
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  return {
+       ...(function() {
+          var yield;
+          throw new Test262Error();
+       }()),
+    }
+};
+
+var iter = gen();
+
+
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-strict-strict.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-strict-strict.js
new file mode 100644
index 0000000000..d621ad6e86
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-identifier-strict-strict.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+'use strict';
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-identifier-strict.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: It's an early error if the generator body has another function body with yield as an identifier in strict mode. (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, onlyStrict]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  (function() {
+      var yield;
+      throw new Test262Error();
+    }())
+};
+
+var iter = gen();
+
+
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-catch.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-catch.js
new file mode 100644
index 0000000000..4bdac14bff
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-catch.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-catch.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: yield Promise.reject(value) is treated as throw value (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield Promise.reject(error);
+  yield "unreachable";
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}).catch(rejectValue => {
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+});
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-for-await-of-async-iterator.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-for-await-of-async-iterator.js
new file mode 100644
index 0000000000..0a842022b9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-for-await-of-async-iterator.js
@@ -0,0 +1,50 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-for-await-of-async-iterator.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: yield * [Promise.reject(value)] is treated as throw value (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+async function * readFile() {
+  yield Promise.reject(error);
+  yield "unreachable";
+}
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  for await (let line of readFile()) {
+    yield line;
+  }
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}, rejectValue => {
+
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-for-await-of-sync-iterator.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-for-await-of-sync-iterator.js
new file mode 100644
index 0000000000..ff27edf171
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-for-await-of-sync-iterator.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-for-await-of-sync-iterator.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: yield Promise.reject(value) in for-await-of is treated as throw value (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+let iterable = [
+  Promise.reject(error),
+  "unreachable"
+];
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  for await (let value of iterable) {
+    yield value;
+  }
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}, rejectValue => {
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-yield-star-async-iterator.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-yield-star-async-iterator.js
new file mode 100644
index 0000000000..b1acb22941
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-yield-star-async-iterator.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-yield-star-async-iterator.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: yield * (async iterator) is treated as throw value (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+async function * readFile() {
+  yield Promise.reject(error);
+  yield "unreachable";
+}
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield * readFile();
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}, rejectValue => {
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+}, $DONE).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-yield-star-sync-iterator.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-yield-star-sync-iterator.js
new file mode 100644
index 0000000000..615c0251b4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next-yield-star-sync-iterator.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-yield-star-sync-iterator.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: yield * (async iterator) is treated as throw value (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+let iterable = [
+  Promise.reject(error),
+  "unreachable"
+];
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield * iterable;
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}, rejectValue => {
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next.js
new file mode 100644
index 0000000000..85ab17c6cd
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-promise-reject-next.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: yield Promise.reject(value) is treated as throw value (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield Promise.reject(error);
+  yield "unreachable";
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}, rejectValue => {
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-spread-arr-multiple.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-spread-arr-multiple.js
new file mode 100644
index 0000000000..ddc969ef1e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-spread-arr-multiple.js
@@ -0,0 +1,50 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-spread-arr-multiple.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Use yield value in a array spread position (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+includes: [compareArray.js]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Array Initializer
+
+    SpreadElement[Yield, Await]:
+      ...AssignmentExpression[+In, ?Yield, ?Await]
+
+---*/
+var arr = ['a', 'b', 'c'];
+var item;
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield [...yield yield];
+};
+
+var iter = gen();
+
+iter.next(false);
+item = iter.next(['a', 'b', 'c']);
+
+item.then(({ done, value }) => {
+  item = iter.next(value);
+
+  item.then(({ done, value }) => {
+    assert.compareArray(value, arr);
+    assert.sameValue(done, false);
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-spread-arr-single.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-spread-arr-single.js
new file mode 100644
index 0000000000..52db92dd16
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-spread-arr-single.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-spread-arr-single.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Use yield value in a array spread position (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Array Initializer
+
+    SpreadElement[Yield, Await]:
+      ...AssignmentExpression[+In, ?Yield, ?Await]
+
+---*/
+var arr = ['a', 'b', 'c'];
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield [...yield];
+};
+
+var iter = gen();
+
+iter.next(false);
+var item = iter.next(arr);
+
+item.then(({ done, value }) => {
+  assert.notSameValue(value, arr, 'value is a new array');
+  assert(Array.isArray(value), 'value is an Array exotic object');
+  assert.sameValue(value.length, 3)
+  assert.sameValue(value[0], 'a');
+  assert.sameValue(value[1], 'b');
+  assert.sameValue(value[2], 'c');
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-spread-obj.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-spread-obj.js
new file mode 100644
index 0000000000..3ebc8fa656
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-spread-obj.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-spread-obj.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Use yield value in a object spread position (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [object-spread, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Spread Properties
+
+    PropertyDefinition[Yield]:
+      (...)
+      ...AssignmentExpression[In, ?Yield]
+
+---*/
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield {
+      ...yield,
+      y: 1,
+      ...yield yield,
+    };
+};
+
+var iter = gen();
+
+iter.next();
+iter.next({ x: 42 });
+iter.next({ x: 'lol' });
+var item = iter.next({ y: 39 });
+
+item.then(({ done, value }) => {
+  assert.sameValue(value.x, 42);
+  assert.sameValue(value.y, 39);
+  assert.sameValue(Object.keys(value).length, 2);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-async-next.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-async-next.js
new file mode 100644
index 0000000000..904c856d7f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-async-next.js
@@ -0,0 +1,219 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-async-next.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Execution order for yield* with async iterator and next() (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    
+---*/
+var log = [];
+var obj = {
+  get [Symbol.iterator]() {
+    log.push({ name: "get [Symbol.iterator]" });
+  },
+  get [Symbol.asyncIterator]() {
+    log.push({
+      name: "get [Symbol.asyncIterator]",
+      thisValue: this
+    });
+    return function() {
+      log.push({
+        name: "call [Symbol.asyncIterator]",
+        thisValue: this,
+        args: [...arguments]
+      });
+      var nextCount = 0;
+      return {
+        name: "asyncIterator",
+        get next() {
+          log.push({
+            name: "get next",
+            thisValue: this
+          });
+          return function() {
+            log.push({
+              name: "call next",
+              thisValue: this,
+              args: [...arguments]
+            });
+
+            nextCount++;
+            if (nextCount == 1) {
+              return {
+                name: "next-promise-1",
+                get then() {
+                  log.push({
+                    name: "get next then (1)",
+                    thisValue: this
+                  });
+                  return function(resolve) {
+                    log.push({
+                      name: "call next then (1)",
+                      thisValue: this,
+                      args: [...arguments]
+                    });
+
+                    resolve({
+                      name: "next-result-1",
+                      get value() {
+                        log.push({
+                          name: "get next value (1)",
+                          thisValue: this
+                        });
+                        return "next-value-1";
+                      },
+                      get done() {
+                        log.push({
+                          name: "get next done (1)",
+                          thisValue: this
+                        });
+                        return false;
+                      }
+                    });
+                  };
+                }
+              };
+            }
+
+            return {
+              name: "next-promise-2",
+              get then() {
+                log.push({
+                  name: "get next then (2)",
+                  thisValue: this
+                });
+                return function(resolve) {
+                  log.push({
+                    name: "call next then (2)",
+                    thisValue: this,
+                    args: [...arguments]
+                  });
+
+                  resolve({
+                    name: "next-result-2",
+                    get value() {
+                      log.push({
+                        name: "get next value (2)",
+                        thisValue: this
+                      });
+                      return "next-value-2";
+                    },
+                    get done() {
+                      log.push({
+                        name: "get next done (2)",
+                        thisValue: this
+                      });
+                      return true;
+                    }
+                  });
+                };
+              }
+            };
+          };
+        }
+      };
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    var v = yield* obj;
+    log.push({
+      name: "after yield*",
+      value: v
+    });
+    return "return-value";
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next("next-arg-1").then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get [Symbol.asyncIterator]");
+  assert.sameValue(log[1].thisValue, obj, "get [Symbol.asyncIterator] thisValue");
+
+  assert.sameValue(log[2].name, "call [Symbol.asyncIterator]");
+  assert.sameValue(log[2].thisValue, obj, "[Symbol.asyncIterator] thisValue");
+  assert.sameValue(log[2].args.length, 0, "[Symbol.asyncIterator] args.length");
+
+  assert.sameValue(log[3].name, "get next");
+  assert.sameValue(log[3].thisValue.name, "asyncIterator", "get next thisValue");
+
+  assert.sameValue(log[4].name, "call next");
+  assert.sameValue(log[4].thisValue.name, "asyncIterator", "next thisValue");
+  assert.sameValue(log[4].args.length, 1, "next args.length");
+  assert.sameValue(log[4].args[0], undefined, "next args[0]");
+
+  assert.sameValue(log[5].name, "get next then (1)");
+  assert.sameValue(log[5].thisValue.name, "next-promise-1", "get next then thisValue");
+
+  assert.sameValue(log[6].name, "call next then (1)");
+  assert.sameValue(log[6].thisValue.name, "next-promise-1", "next then thisValue");
+  assert.sameValue(log[6].args.length, 2, "next then args.length");
+  assert.sameValue(typeof log[6].args[0], "function", "next then args[0]");
+  assert.sameValue(typeof log[6].args[1], "function", "next then args[1]");
+
+  assert.sameValue(log[7].name, "get next done (1)");
+  assert.sameValue(log[7].thisValue.name, "next-result-1", "get next done thisValue");
+
+  assert.sameValue(log[8].name, "get next value (1)");
+  assert.sameValue(log[8].thisValue.name, "next-result-1", "get next value thisValue");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 9, "log.length");
+
+  iter.next("next-arg-2").then(v => {
+    assert.sameValue(log[9].name, "call next");
+    assert.sameValue(log[9].thisValue.name, "asyncIterator", "next thisValue");
+    assert.sameValue(log[9].args.length, 1, "next args.length");
+    assert.sameValue(log[9].args[0], "next-arg-2", "next args[0]");
+
+    assert.sameValue(log[10].name, "get next then (2)");
+    assert.sameValue(log[10].thisValue.name, "next-promise-2", "get next then thisValue");
+
+    assert.sameValue(log[11].name, "call next then (2)");
+    assert.sameValue(log[11].thisValue.name, "next-promise-2", "next then thisValue");
+    assert.sameValue(log[11].args.length, 2, "next then args.length");
+    assert.sameValue(typeof log[11].args[0], "function", "next then args[0]");
+    assert.sameValue(typeof log[11].args[1], "function", "next then args[1]");
+
+    assert.sameValue(log[12].name, "get next done (2)");
+    assert.sameValue(log[12].thisValue.name, "next-result-2", "get next done thisValue");
+
+    assert.sameValue(log[13].name, "get next value (2)");
+    assert.sameValue(log[13].thisValue.name, "next-result-2", "get next value thisValue");
+
+    assert.sameValue(log[14].name, "after yield*");
+    assert.sameValue(log[14].value, "next-value-2");
+
+    assert.sameValue(v.value, "return-value");
+    assert.sameValue(v.done, true);
+
+    assert.sameValue(log.length, 15, "log.length");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-async-return.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-async-return.js
new file mode 100644
index 0000000000..4c56c20d31
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-async-return.js
@@ -0,0 +1,235 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-async-return.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: execution order for yield* with async iterator and return() (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      c. Else,
+        i. Assert: received.[[Type]] is return.
+        ii. Let return be ? GetMethod(iterator, "return").
+        iii. If return is undefined, return Completion(received).
+        iv. Let innerReturnResult be ? Call(return, iterator, « received.[[Value]] »).
+        v. If generatorKind is async, then set innerReturnResult to ? Await(innerReturnResult).
+        ...
+        vii. Let done be ? IteratorComplete(innerReturnResult).
+        viii. If done is true, then
+             1. Let value be ? IteratorValue(innerReturnResult).
+             2. If generatorKind is async, then set value to ? Await(value).
+             3. Return Completion{[[Type]]: return, [[Value]]: value, [[Target]]: empty}.
+        ix. If generatorKind is async, then let received be AsyncGeneratorYield(? IteratorValue(innerResult)).
+        ...
+
+    AsyncGeneratorYield ( value )
+    ...
+    8. Return ! AsyncGeneratorResolve(generator, value, false).
+    ...
+
+---*/
+var log = [];
+var obj = {
+  [Symbol.asyncIterator]() {
+    var returnCount = 0;
+    return {
+      name: 'asyncIterator',
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get return() {
+        log.push({
+          name: "get return",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call return",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          returnCount++;
+          if (returnCount == 1) {
+            return {
+              name: "return-promise-1",
+              get then() {
+                log.push({
+                  name: "get return then (1)",
+                  thisValue: this
+                });
+                return function(resolve) {
+                  log.push({
+                    name: "call return then (1)",
+                    thisValue: this,
+                    args: [...arguments]
+                  });
+
+                  resolve({
+                    name: "return-result-1",
+                    get value() {
+                      log.push({
+                        name: "get return value (1)",
+                        thisValue: this
+                      });
+                      return "return-value-1";
+                    },
+                    get done() {
+                      log.push({
+                        name: "get return done (1)",
+                        thisValue: this
+                      });
+                      return false;
+                    }
+                  });
+                };
+              }
+            };
+          }
+
+          return {
+            name: "return-promise-2",
+            get then() {
+              log.push({
+                name: "get return then (2)",
+                thisValue: this
+              });
+              return function(resolve) {
+                log.push({
+                  name: "call return then (2)",
+                  thisValue: this,
+                  args: [...arguments]
+                });
+
+                resolve({
+                  name: "return-result-2",
+                  get value() {
+                    log.push({
+                      name: "get return value (2)",
+                      thisValue: this
+                    });
+                    return "return-value-2";
+                  },
+                  get done() {
+                    log.push({
+                      name: "get return done (2)",
+                      thisValue: this
+                    });
+                    return true;
+                  }
+                });
+              };
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    yield* obj;
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.return("return-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get return");
+    assert.sameValue(log[2].thisValue.name, "asyncIterator", "get return thisValue");
+
+    assert.sameValue(log[3].name, "call return");
+    assert.sameValue(log[3].thisValue.name, "asyncIterator", "return thisValue");
+    assert.sameValue(log[3].args.length, 1, "return args.length");
+    assert.sameValue(log[3].args[0], "return-arg-1", "return args[0]");
+
+    assert.sameValue(log[4].name, "get return then (1)");
+    assert.sameValue(log[4].thisValue.name, "return-promise-1", "get return then thisValue");
+
+    assert.sameValue(log[5].name, "call return then (1)");
+    assert.sameValue(log[5].thisValue.name, "return-promise-1", "return then thisValue");
+    assert.sameValue(log[5].args.length, 2, "return then args.length");
+    assert.sameValue(typeof log[5].args[0], "function", "return then args[0]");
+    assert.sameValue(typeof log[5].args[1], "function", "return then args[1]");
+
+    assert.sameValue(log[6].name, "get return done (1)");
+    assert.sameValue(log[6].thisValue.name, "return-result-1", "get return done thisValue");
+
+    assert.sameValue(log[7].name, "get return value (1)");
+    assert.sameValue(log[7].thisValue.name, "return-result-1", "get return value thisValue");
+
+    assert.sameValue(v.value, "return-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 8, "log.length");
+
+    iter.return("return-arg-2").then(v => {
+      assert.sameValue(log[8].name, "get return");
+      assert.sameValue(log[8].thisValue.name, "asyncIterator", "get return thisValue");
+
+      assert.sameValue(log[9].name, "call return");
+      assert.sameValue(log[9].thisValue.name, "asyncIterator", "return thisValue");
+      assert.sameValue(log[9].args.length, 1, "return args.length");
+      assert.sameValue(log[9].args[0], "return-arg-2", "return args[0]");
+
+      assert.sameValue(log[10].name, "get return then (2)");
+      assert.sameValue(log[10].thisValue.name, "return-promise-2", "get return then thisValue");
+
+      assert.sameValue(log[11].name, "call return then (2)");
+      assert.sameValue(log[11].thisValue.name, "return-promise-2", "return then thisValue");
+      assert.sameValue(log[11].args.length, 2, "return then args.length");
+      assert.sameValue(typeof log[11].args[0], "function", "return then args[0]");
+      assert.sameValue(typeof log[11].args[1], "function", "return then args[1]");
+
+      assert.sameValue(log[12].name, "get return done (2)");
+      assert.sameValue(log[12].thisValue.name, "return-result-2", "get return done thisValue");
+
+      assert.sameValue(log[13].name, "get return value (2)");
+      assert.sameValue(log[13].thisValue.name, "return-result-2", "get return value thisValue");
+
+      assert.sameValue(v.value, "return-value-2");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 14, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-async-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-async-throw.js
new file mode 100644
index 0000000000..87d3da4090
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-async-throw.js
@@ -0,0 +1,243 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-async-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: execution order for yield* with async iterator and throw() (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      b. Else if received.[[Type]] is throw, then
+        i. Let throw be ? GetMethod(iterator, "throw").
+        ii. If throw is not undefined, then
+          1. Let innerResult be ? Call(throw, iterator, « received.[[Value]] »).
+          2. If generatorKind is async, then set innerResult to ? Await(innerResult).
+          ...
+          5. Let done be ? IteratorComplete(innerResult).
+          6. If done is true, then
+            a. Let resultValue be Return ? IteratorValue(innerResult).
+            b. If generatorKind is async, then set resultValue to ? Await(resultValue).
+            c. Return resultValue.
+          7. If generatorKind is async, then let received be AsyncGeneratorYield(? IteratorValue(innerResult)).
+      ...
+
+    AsyncGeneratorYield ( value )
+
+    ...
+    8. Return ! AsyncGeneratorResolve(generator, value, false).
+    ...
+
+---*/
+var log = [];
+var obj = {
+  [Symbol.asyncIterator]() {
+    var throwCount = 0;
+    return {
+      name: "asyncIterator",
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get throw() {
+        log.push({
+          name: "get throw",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call throw",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          throwCount++;
+          if (throwCount == 1) {
+            return {
+              name: "throw-promise-1",
+              get then() {
+                log.push({
+                  name: "get throw then (1)",
+                  thisValue: this
+                });
+                return function(resolve) {
+                  log.push({
+                    name: "call throw then (1)",
+                    thisValue: this,
+                    args: [...arguments]
+                  });
+
+                  resolve({
+                    name: "throw-result-1",
+                    get value() {
+                      log.push({
+                        name: "get throw value (1)",
+                        thisValue: this
+                      });
+                      return "throw-value-1";
+                    },
+                    get done() {
+                      log.push({
+                        name: "get throw done (1)",
+                        thisValue: this
+                      });
+                      return false;
+                    }
+                  });
+                };
+              }
+            };
+          }
+
+          return {
+            name: "throw-promise-2",
+            get then() {
+              log.push({
+                name: "get throw then (2)",
+                thisValue: this
+              });
+              return function(resolve) {
+                log.push({
+                  name: "call throw then (2)",
+                  thisValue: this,
+                  args: [...arguments]
+                });
+
+                resolve({
+                  name: "throw-result-2",
+                  get value() {
+                    log.push({
+                      name: "get throw value (2)",
+                      thisValue: this
+                    });
+                    return "throw-value-2";
+                  },
+                  get done() {
+                    log.push({
+                      name: "get throw done (2)",
+                      thisValue: this
+                    });
+                    return true;
+                  }
+                });
+              };
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    var v = yield* obj;
+    log.push({
+      name: "after yield*",
+      value: v
+    });
+    return "return-value";
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.throw("throw-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get throw");
+    assert.sameValue(log[2].thisValue.name, "asyncIterator", "get throw thisValue");
+
+    assert.sameValue(log[3].name, "call throw");
+    assert.sameValue(log[3].thisValue.name, "asyncIterator", "throw thisValue");
+    assert.sameValue(log[3].args.length, 1, "throw args.length");
+    assert.sameValue(log[3].args[0], "throw-arg-1", "throw args[0]");
+
+    assert.sameValue(log[4].name, "get throw then (1)");
+    assert.sameValue(log[4].thisValue.name, "throw-promise-1", "get throw thisValue");
+
+    assert.sameValue(log[5].name, "call throw then (1)");
+    assert.sameValue(log[5].thisValue.name, "throw-promise-1", "throw thisValue");
+    assert.sameValue(log[5].args.length, 2, "throw then args.length");
+    assert.sameValue(typeof log[5].args[0], "function", "throw then args[0]");
+    assert.sameValue(typeof log[5].args[1], "function", "throw then args[1]");
+
+    assert.sameValue(log[6].name, "get throw done (1)");
+    assert.sameValue(log[6].thisValue.name, "throw-result-1", "get throw done thisValue");
+
+    assert.sameValue(log[7].name, "get throw value (1)");
+    assert.sameValue(log[7].thisValue.name, "throw-result-1", "get throw value thisValue");
+
+    assert.sameValue(v.value, "throw-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 8, "log.length");
+
+    iter.throw("throw-arg-2").then(v => {
+      assert.sameValue(log[8].name, "get throw");
+      assert.sameValue(log[8].thisValue.name, "asyncIterator", "get throw thisValue");
+
+      assert.sameValue(log[9].name, "call throw");
+      assert.sameValue(log[9].thisValue.name, "asyncIterator", "throw thisValue");
+      assert.sameValue(log[9].args.length, 1, "throw args.length");
+      assert.sameValue(log[9].args[0], "throw-arg-2", "throw args[0]");
+
+      assert.sameValue(log[10].name, "get throw then (2)");
+      assert.sameValue(log[10].thisValue.name, "throw-promise-2", "get throw thisValue");
+
+      assert.sameValue(log[11].name, "call throw then (2)");
+      assert.sameValue(log[11].thisValue.name, "throw-promise-2", "throw thisValue");
+      assert.sameValue(log[11].args.length, 2, "throw then args.length");
+      assert.sameValue(typeof log[11].args[0], "function", "throw then args[0]");
+      assert.sameValue(typeof log[11].args[1], "function", "throw then args[1]");
+
+      assert.sameValue(log[12].name, "get throw done (2)");
+      assert.sameValue(log[12].thisValue.name, "throw-result-2", "get throw done thisValue");
+
+      assert.sameValue(log[13].name, "get throw value (2)");
+      assert.sameValue(log[13].thisValue.name, "throw-result-2", "get throw value thisValue");
+
+      assert.sameValue(log[14].name, "after yield*");
+      assert.sameValue(log[14].value, "throw-value-2");
+
+      assert.sameValue(v.value, "return-value");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 15, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-expr-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-expr-abrupt.js
new file mode 100644
index 0000000000..4a28cca3db
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-expr-abrupt.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-expr-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Abrupt completion while getting yield* operand (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    ...
+
+---*/
+var obj = {};
+var abrupt = function() {
+  throw obj;
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* abrupt();
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, obj, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-get-abrupt.js
new file mode 100644
index 0000000000..2d0300fa3c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-get-abrupt.js
@@ -0,0 +1,74 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-get-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Abrupt completion while getting [Symbol.asyncIterator] (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  get [Symbol.asyncIterator]() {
+    throw reason;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-boolean-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-boolean-throw.js
new file mode 100644
index 0000000000..931d2763b7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-boolean-throw.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-not-callable-boolean-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (boolean) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    3. If func is either undefined or null, return undefined.
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]: false
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-number-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-number-throw.js
new file mode 100644
index 0000000000..087a62f01e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-number-throw.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-not-callable-number-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (number) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    3. If func is either undefined or null, return undefined.
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]: 0
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-object-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-object-throw.js
new file mode 100644
index 0000000000..d8dc7764a7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-object-throw.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-not-callable-object-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (object) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    3. If func is either undefined or null, return undefined.
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]: {}
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-string-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-string-throw.js
new file mode 100644
index 0000000000..162bbdd077
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-string-throw.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-not-callable-string-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (string) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    3. If func is either undefined or null, return undefined.
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]: ''
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-symbol-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-symbol-throw.js
new file mode 100644
index 0000000000..239b0de71b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-not-callable-symbol-throw.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-not-callable-symbol-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (symbol) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    3. If func is either undefined or null, return undefined.
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]: Symbol.asyncIterator
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-null-sync-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-null-sync-get-abrupt.js
new file mode 100644
index 0000000000..d65a282855
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-null-sync-get-abrupt.js
@@ -0,0 +1,79 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-null-sync-get-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Abrupt completion while getting @@iterator after null @@asyncIterator (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+
+---*/
+var calls = 0;
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw reason;
+  },
+  get [Symbol.asyncIterator]() {
+    calls += 1;
+    return null;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, 'reject reason');
+  assert.sameValue(calls, 1);
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-abrupt.js
new file mode 100644
index 0000000000..d210513355
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-abrupt.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Abrupt completion while calling [Symbol.asyncIterator] (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    throw reason;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-boolean-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-boolean-throw.js
new file mode 100644
index 0000000000..1cd251b3b9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-boolean-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-boolean-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - boolean (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return true;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-null-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-null-throw.js
new file mode 100644
index 0000000000..fd65d73653
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-null-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-null-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - null (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return null;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-number-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-number-throw.js
new file mode 100644
index 0000000000..2eb11f2b2a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-number-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-number-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - number (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return 42;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-string-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-string-throw.js
new file mode 100644
index 0000000000..76cfafb451
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-string-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-string-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - string (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return '42';
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-symbol-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-symbol-throw.js
new file mode 100644
index 0000000000..8ea4928706
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-symbol-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-symbol-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - symbol (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return Symbol.asyncIterator;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-undefined-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-undefined-throw.js
new file mode 100644
index 0000000000..5ab7266b49
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-returns-undefined-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-undefined-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - undefined (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return undefined;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-undefined-sync-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-undefined-sync-get-abrupt.js
new file mode 100644
index 0000000000..25c3966324
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-async-undefined-sync-get-abrupt.js
@@ -0,0 +1,79 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-undefined-sync-get-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Abrupt completion while getting @@iterator after undefined @@asyncIterator (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+
+---*/
+var calls = 0;
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw reason;
+  },
+  get [Symbol.asyncIterator]() {
+    calls += 1;
+    return undefined;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, 'reject reason');
+  assert.sameValue(calls, 1);
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-get-abrupt.js
new file mode 100644
index 0000000000..efcfbbf402
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-get-abrupt.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-get-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Abrupt completion while getting [Symbol.iterator] (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw reason;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-boolean-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-boolean-throw.js
new file mode 100644
index 0000000000..48a010d224
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-boolean-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-not-callable-boolean-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (boolean) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]: false
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-number-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-number-throw.js
new file mode 100644
index 0000000000..f987249e10
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-number-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-not-callable-number-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (number) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]: 0
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-object-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-object-throw.js
new file mode 100644
index 0000000000..a35d12ecb7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-object-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-not-callable-object-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (object) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]: {}
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-string-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-string-throw.js
new file mode 100644
index 0000000000..fb7056aeb0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-string-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-not-callable-string-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (string) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]: ''
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-symbol-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-symbol-throw.js
new file mode 100644
index 0000000000..4aac649946
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-not-callable-symbol-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-not-callable-symbol-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (symbol) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]: Symbol.iterator
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-abrupt.js
new file mode 100644
index 0000000000..9052274aaf
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-abrupt.js
@@ -0,0 +1,67 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Abrupt completion while calling [Symbol.iterator] (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  [Symbol.iterator]() {
+    throw reason;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-boolean-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-boolean-throw.js
new file mode 100644
index 0000000000..e4ca23f728
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-boolean-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-boolean-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.iterator]() - boolean (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return true;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-null-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-null-throw.js
new file mode 100644
index 0000000000..f6c22f9aeb
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-null-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-null-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.iterator]() - null (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return null;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-number-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-number-throw.js
new file mode 100644
index 0000000000..e9777aa6f4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-number-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-number-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.iterator]() - number (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return 0;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-string-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-string-throw.js
new file mode 100644
index 0000000000..c58d7874f2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-string-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-string-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.iterator]() - string (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return '';
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-symbol-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-symbol-throw.js
new file mode 100644
index 0000000000..fea53d164b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-symbol-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-symbol-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.iterator]() - symbol (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return Symbol.iterator;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-undefined-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-undefined-throw.js
new file mode 100644
index 0000000000..5c11a72ea0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-getiter-sync-returns-undefined-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-undefined-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Non object returned by [Symbol.iterator]() - undefined (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return undefined;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-call-done-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-call-done-get-abrupt.js
new file mode 100644
index 0000000000..0f111bb149
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-call-done-get-abrupt.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-call-done-get-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Abrupt completion while getting done (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        ...
+        v. Let done be ? IteratorComplete(innerResult).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          get done() {
+            throw reason;
+          }
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-call-returns-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-call-returns-abrupt.js
new file mode 100644
index 0000000000..87744633df
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-call-returns-abrupt.js
@@ -0,0 +1,65 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-call-returns-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Abrupt completion while calling next (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        throw reason;
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-call-value-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-call-value-get-abrupt.js
new file mode 100644
index 0000000000..ffc74aec9b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-call-value-get-abrupt.js
@@ -0,0 +1,75 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-call-value-get-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Abrupt completion while getting value (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        ...
+        vi. If done is true, then
+           1. Return ? IteratorValue(innerResult).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          done: true,
+          get value() {
+            throw reason;
+          }
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-get-abrupt.js
new file mode 100644
index 0000000000..e731e31103
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-get-abrupt.js
@@ -0,0 +1,65 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-get-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Abrupt completion while getting next (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      get next() {
+        throw reason;
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-non-object-ignores-then.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-non-object-ignores-then.js
new file mode 100644
index 0000000000..0051905a6b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-non-object-ignores-then.js
@@ -0,0 +1,85 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-non-object-ignores-then.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: If next() value is not-object, do not access respective then property (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+
+---*/
+Number.prototype.then = function() {
+  throw new Test262Error('Number#then should not be used');
+};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return 42;
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, 'TypeError');
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-boolean-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-boolean-throw.js
new file mode 100644
index 0000000000..64076a393c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-boolean-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-boolean-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Not-callable next value in a yield star position - boolean (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: true
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-null-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-null-throw.js
new file mode 100644
index 0000000000..f31869aca3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-null-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-null-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Not-callable next value in a yield star position - null (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: null
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-number-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-number-throw.js
new file mode 100644
index 0000000000..b94fad4ed0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-number-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-number-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Not-callable next value in a yield star position - number (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: 42
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-object-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-object-throw.js
new file mode 100644
index 0000000000..3dbcfe3777
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-object-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-object-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Not-callable next value in a yield star position - object (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: {}
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-string-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-string-throw.js
new file mode 100644
index 0000000000..2374798265
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-string-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-string-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Not-callable next value in a yield star position - string (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: ''
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-symbol-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-symbol-throw.js
new file mode 100644
index 0000000000..a93dbe7353
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-symbol-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-symbol-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Not-callable next value in a yield star position - symbol (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: Symbol('oi')
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-undefined-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-undefined-throw.js
new file mode 100644
index 0000000000..78bd90aa14
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-not-callable-undefined-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-undefined-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Not-callable next value in a yield star position - undefined (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: undefined
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-get-abrupt.js
new file mode 100644
index 0000000000..ceb021d277
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-get-abrupt.js
@@ -0,0 +1,89 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-get-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Return abrupt after getting next().then (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    8. Let then be Get(resolution, "then").
+    ...
+    10. Get thenAction be then.[[Value]].
+    ...
+    12. Perform EnqueueJob("PromiseJobs", PromiseResolveThenableJob, « promise,
+        resolution, thenAction »).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          get then() {
+            throw reason;
+          }
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, 'reject reason');
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-boolean-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-boolean-fulfillpromise.js
new file mode 100644
index 0000000000..d077cceb47
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-boolean-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-boolean-fulfillpromise.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: FulfillPromise if next().then is not-callable (boolean) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: true,
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-null-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-null-fulfillpromise.js
new file mode 100644
index 0000000000..a05a88a2a1
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-null-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-null-fulfillpromise.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: FulfillPromise if next().then is not-callable (null) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: null,
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-number-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-number-fulfillpromise.js
new file mode 100644
index 0000000000..dc2cfde595
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-number-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-number-fulfillpromise.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: FulfillPromise if next().then is not-callable (number) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: 39,
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-object-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-object-fulfillpromise.js
new file mode 100644
index 0000000000..9437c9fe3e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-object-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-object-fulfillpromise.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: FulfillPromise if next().then is not-callable (object) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: {},
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-string-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-string-fulfillpromise.js
new file mode 100644
index 0000000000..160cb63722
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-string-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-string-fulfillpromise.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: FulfillPromise if next().then is not-callable (string) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: '',
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-symbol-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-symbol-fulfillpromise.js
new file mode 100644
index 0000000000..8d2a6446d2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-symbol-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-symbol-fulfillpromise.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: FulfillPromise if next().then is not-callable (symbol) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: Symbol('oi'),
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-undefined-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-undefined-fulfillpromise.js
new file mode 100644
index 0000000000..43c41e8349
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-non-callable-undefined-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-undefined-fulfillpromise.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: FulfillPromise if next().then is not-callable (undefined) (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: undefined,
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-returns-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-returns-abrupt.js
new file mode 100644
index 0000000000..405bc63761
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-next-then-returns-abrupt.js
@@ -0,0 +1,89 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-returns-abrupt.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: Return abrupt after calling next().then (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    8. Let then be Get(resolution, "then").
+    ...
+    10. Get thenAction be then.[[Value]].
+    ...
+    12. Perform EnqueueJob("PromiseJobs", PromiseResolveThenableJob, « promise,
+        resolution, thenAction »).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then() {
+            throw reason;
+          }
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, 'reject reason');
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-sync-next.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-sync-next.js
new file mode 100644
index 0000000000..f8e09c51be
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-sync-next.js
@@ -0,0 +1,222 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-sync-next.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: execution order for yield* with sync iterator and next() (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    5. Let received be NormalCompletion(undefined).
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        i. Let innerResult be ? IteratorNext(iterator, received.[[Value]]).
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        ...
+        v. Let done be ? IteratorComplete(innerResult).
+        vi. If done is true, then
+           1. Return ? IteratorValue(innerResult).
+        vii. Let received be GeneratorYield(innerResult).
+      ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    %AsyncFromSyncIteratorPrototype%.next ( value )
+
+    ...
+    5. Let nextResult be IteratorNext(syncIterator, value).
+    ...
+    7. Let nextValue be IteratorValue(nextResult).
+    ...
+    9. Let nextDone be IteratorComplete(nextResult).
+    ...
+    12. Perform ! Call(valueWrapperCapability.[[Resolve]], undefined,
+        « nextValue »).
+    ...
+    14. Set onFulfilled.[[Done]] to nextDone.
+    15. Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]],
+        onFulfilled, undefined, promiseCapability).
+    ...
+
+    Async Iterator Value Unwrap Functions
+
+    1. Return ! CreateIterResultObject(value, F.[[Done]]).
+
+---*/
+var log = [];
+var obj = {
+  get [Symbol.iterator]() {
+    log.push({
+      name: "get [Symbol.iterator]",
+      thisValue: this
+    });
+    return function() {
+      log.push({
+        name: "call [Symbol.iterator]",
+        thisValue: this,
+        args: [...arguments]
+      });
+      var nextCount = 0;
+      return {
+        name: "syncIterator",
+        get next() {
+          log.push({
+            name: "get next",
+            thisValue: this
+          });
+          return function() {
+            log.push({
+              name: "call next",
+              thisValue: this,
+              args: [...arguments]
+            });
+
+            nextCount++;
+            if (nextCount == 1) {
+              return {
+                name: "next-result-1",
+                get value() {
+                  log.push({
+                    name: "get next value (1)",
+                    thisValue: this
+                  });
+                  return "next-value-1";
+                },
+                get done() {
+                  log.push({
+                    name: "get next done (1)",
+                    thisValue: this
+                  });
+                  return false;
+                }
+              };
+            }
+
+            return {
+              name: "next-result-2",
+              get value() {
+                log.push({
+                  name: "get next value (2)",
+                  thisValue: this
+                });
+                return "next-value-2";
+              },
+              get done() {
+                log.push({
+                  name: "get next done (2)",
+                  thisValue: this
+                });
+                return true;
+              }
+            };
+          };
+        }
+      };
+    };
+  },
+  get [Symbol.asyncIterator]() {
+    log.push({ name: "get [Symbol.asyncIterator]" });
+    return null;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    var v = yield* obj;
+    log.push({
+      name: "after yield*",
+      value: v
+    });
+    return "return-value";
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next("next-arg-1").then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get [Symbol.asyncIterator]");
+
+  assert.sameValue(log[2].name, "get [Symbol.iterator]");
+  assert.sameValue(log[2].thisValue, obj, "get [Symbol.iterator] thisValue");
+
+  assert.sameValue(log[3].name, "call [Symbol.iterator]");
+  assert.sameValue(log[3].thisValue, obj, "[Symbol.iterator] thisValue");
+  assert.sameValue(log[3].args.length, 0, "[Symbol.iterator] args.length");
+
+  assert.sameValue(log[4].name, "get next");
+  assert.sameValue(log[4].thisValue.name, "syncIterator", "get next thisValue");
+
+  assert.sameValue(log[5].name, "call next");
+  assert.sameValue(log[5].thisValue.name, "syncIterator", "next thisValue");
+  assert.sameValue(log[5].args.length, 1, "next args.length");
+  assert.sameValue(log[5].args[0], undefined, "next args[0]");
+
+  assert.sameValue(log[6].name, "get next done (1)");
+  assert.sameValue(log[6].thisValue.name, "next-result-1", "get next done thisValue");
+
+  assert.sameValue(log[7].name, "get next value (1)");
+  assert.sameValue(log[7].thisValue.name, "next-result-1", "get next value thisValue");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 8, "log.length");
+
+  iter.next("next-arg-2").then(v => {
+    assert.sameValue(log[8].name, "call next");
+    assert.sameValue(log[8].thisValue.name, "syncIterator", "next thisValue");
+    assert.sameValue(log[8].args.length, 1, "next args.length");
+    assert.sameValue(log[8].args[0], "next-arg-2", "next args[0]");
+
+    assert.sameValue(log[9].name, "get next done (2)");
+    assert.sameValue(log[9].thisValue.name, "next-result-2", "get next done thisValue");
+
+    assert.sameValue(log[10].name, "get next value (2)");
+    assert.sameValue(log[10].thisValue.name, "next-result-2", "get next value thisValue");
+
+    assert.sameValue(log[11].name, "after yield*");
+    assert.sameValue(log[11].value, "next-value-2");
+
+    assert.sameValue(v.value, "return-value");
+    assert.sameValue(v.done, true);
+
+    assert.sameValue(log.length, 12, "log.length");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-sync-return.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-sync-return.js
new file mode 100644
index 0000000000..55f649a41c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-sync-return.js
@@ -0,0 +1,197 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-sync-return.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: execution order for yield* with sync iterator and return() (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      c. Else,
+        i. Assert: received.[[Type]] is return.
+        ii. Let return be ? GetMethod(iterator, "return").
+        iii. If return is undefined, return Completion(received).
+        iv. Let innerReturnResult be ? Call(return, iterator,
+            « received.[[Value]] »).
+        v. If generatorKind is async, then set innerReturnResult to
+           ? Await(innerReturnResult).
+        ...
+        vii. Let done be ? IteratorComplete(innerReturnResult).
+        viii. If done is true, then
+             1. Let value be ? IteratorValue(innerReturnResult).
+             2. Return Completion{[[Type]]: return, [[Value]]: value,
+                [[Target]]: empty}.
+        ix. Let received be GeneratorYield(innerResult).
+
+    %AsyncFromSyncIteratorPrototype%.return ( value )
+
+    5. Let return be GetMethod(syncIterator, "return").
+    ...
+    ...
+    8. Let returnResult be Call(return, syncIterator, « value »).
+    ...
+    11. Let returnValue be IteratorValue(returnResult).
+    ..
+    13. Let returnDone be IteratorComplete(returnResult).
+    ...
+    16. Perform ! Call(valueWrapperCapability.[[Resolve]], undefined, « returnValue »).
+    ...
+    18. Set onFulfilled.[[Done]] to returnDone.
+    19. Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]],
+        onFulfilled, undefined, promiseCapability).
+    ...
+
+---*/
+var log = [];
+var obj = {
+  [Symbol.iterator]() {
+    var returnCount = 0;
+    return {
+      name: "syncIterator",
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get return() {
+        log.push({
+          name: "get return",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call return",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          returnCount++;
+          if (returnCount == 1) {
+            return {
+              name: "return-result-1",
+              get value() {
+                log.push({
+                  name: "get return value (1)",
+                  thisValue: this
+                });
+                return "return-value-1";
+              },
+              get done() {
+                log.push({
+                  name: "get return done (1)",
+                  thisValue: this
+                });
+                return false;
+              }
+            };
+          }
+
+          return {
+            name: "return-result-2",
+            get value() {
+              log.push({
+                name: "get return value (2)",
+                thisValue: this
+              });
+              return "return-value-2";
+            },
+            get done() {
+              log.push({
+                name: "get return done (2)",
+                thisValue: this
+              });
+              return true;
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    yield* obj;
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.return("return-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get return");
+    assert.sameValue(log[2].thisValue.name, "syncIterator", "get return thisValue");
+
+    assert.sameValue(log[3].name, "call return");
+    assert.sameValue(log[3].thisValue.name, "syncIterator", "return thisValue");
+    assert.sameValue(log[3].args.length, 1, "return args.length");
+    assert.sameValue(log[3].args[0], "return-arg-1", "return args[0]");
+
+    assert.sameValue(log[4].name, "get return done (1)");
+    assert.sameValue(log[4].thisValue.name, "return-result-1", "get return done thisValue");
+
+    assert.sameValue(log[5].name, "get return value (1)");
+    assert.sameValue(log[5].thisValue.name, "return-result-1", "get return value thisValue");
+
+    assert.sameValue(v.value, "return-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 6, "log.length");
+
+    iter.return().then(v => {
+      assert.sameValue(log[6].name, "get return");
+      assert.sameValue(log[6].thisValue.name, "syncIterator", "get return thisValue");
+
+      assert.sameValue(log[7].name, "call return");
+      assert.sameValue(log[7].thisValue.name, "syncIterator", "get return thisValue");
+      assert.sameValue(log[7].args.length, 1, "return args.length");
+      assert.sameValue(log[7].args[0], undefined, "return args[0]");
+
+      assert.sameValue(log[8].name, "get return done (2)");
+      assert.sameValue(log[8].thisValue.name, "return-result-2", "get return done thisValue");
+
+      assert.sameValue(log[9].name, "get return value (2)");
+      assert.sameValue(log[9].thisValue.name, "return-result-2", "get return value thisValue");
+
+      assert.sameValue(v.value, "return-value-2");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 10, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/named-yield-star-sync-throw.js b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-sync-throw.js
new file mode 100644
index 0000000000..431199311e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/named-yield-star-sync-throw.js
@@ -0,0 +1,203 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-sync-throw.case
+// - src/async-generators/default/async-expression-named.template
+/*---
+description: execution order for yield* with sync iterator and throw() (Named async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      b. Else if received.[[Type]] is throw, then
+        i. Let throw be ? GetMethod(iterator, "throw").
+        ii. If throw is not undefined, then
+          1. Let innerResult be ? Call(throw, iterator, « received.[[Value]] »).
+          2. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+          ...
+          5. Let done be ? IteratorComplete(innerResult).
+          6. If done is true, then
+            a. Return ? IteratorValue(innerResult).
+          7. Let received be GeneratorYield(innerResult).
+      ...
+
+    %AsyncFromSyncIteratorPrototype%.throw ( value )
+
+    ...
+    5. Let throw be GetMethod(syncIterator, "throw").
+    ...
+    8. Let throwResult be Call(throw, syncIterator, « value »).
+    ...
+    11. Let throwValue be IteratorValue(throwResult).
+    ...
+    13. Let throwDone be IteratorComplete(throwResult).
+    ...
+    16. Perform ! Call(valueWrapperCapability.[[Resolve]], undefined,
+        « throwValue »).
+    ...
+    18. Set onFulfilled.[[Done]] to throwDone.
+    19. Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]],
+        onFulfilled, undefined, promiseCapability).
+    ...
+
+---*/
+var log = [];
+var obj = {
+  [Symbol.iterator]() {
+    var throwCount = 0;
+    return {
+      name: "syncIterator",
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get throw() {
+        log.push({
+          name: "get throw",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call throw",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          throwCount++;
+          if (throwCount == 1) {
+            return {
+              name: "throw-result-1",
+              get value() {
+                log.push({
+                  name: "get throw value (1)",
+                  thisValue: this
+                });
+                return "throw-value-1";
+              },
+              get done() {
+                log.push({
+                  name: "get throw done (1)",
+                  thisValue: this
+                });
+                return false;
+              }
+            };
+          }
+
+          return {
+            name: "throw-result-2",
+            get value() {
+              log.push({
+                name: "get throw value (2)",
+                thisValue: this
+              });
+              return "throw-value-2";
+            },
+            get done() {
+              log.push({
+                name: "get throw done (2)",
+                thisValue: this
+              });
+              return true;
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *g() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    var v = yield* obj;
+    log.push({
+      name: "after yield*",
+      value: v
+    });
+    return "return-value";
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.throw("throw-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get throw");
+    assert.sameValue(log[2].thisValue.name, "syncIterator", "get throw thisValue");
+
+    assert.sameValue(log[3].name, "call throw");
+    assert.sameValue(log[3].thisValue.name, "syncIterator", "throw thisValue");
+    assert.sameValue(log[3].args.length, 1, "throw args.length");
+    assert.sameValue(log[3].args[0], "throw-arg-1", "throw args[0]");
+
+    assert.sameValue(log[4].name, "get throw done (1)");
+    assert.sameValue(log[4].thisValue.name, "throw-result-1", "get throw done thisValue");
+
+    assert.sameValue(log[5].name, "get throw value (1)");
+    assert.sameValue(log[5].thisValue.name, "throw-result-1", "get throw value thisValue");
+
+    assert.sameValue(v.value, "throw-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 6, "log.length");
+
+    iter.throw().then(v => {
+      assert.sameValue(log[6].name, "get throw");
+      assert.sameValue(log[6].thisValue.name, "syncIterator", "get throw thisValue");
+
+      assert.sameValue(log[7].name, "call throw");
+      assert.sameValue(log[7].thisValue.name, "syncIterator", "throw thisValue");
+      assert.sameValue(log[7].args.length, 1, "throw args.length");
+      assert.sameValue(log[7].args[0], undefined, "throw args[0]");
+
+      assert.sameValue(log[8].name, "get throw done (2)");
+      assert.sameValue(log[8].thisValue.name, "throw-result-2", "get throw done thisValue");
+
+      assert.sameValue(log[9].name, "get throw value (2)");
+      assert.sameValue(log[9].thisValue.name, "throw-result-2", "get throw value thisValue");
+
+      assert.sameValue(log[10].name, "after yield*");
+      assert.sameValue(log[10].value, "throw-value-2");
+
+      assert.sameValue(v.value, "return-value");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 11, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/object-destructuring-param-strict-body.js b/js/src/tests/test262/language/expressions/async-generator/object-destructuring-param-strict-body.js
new file mode 100644
index 0000000000..98ffca1da1
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/object-destructuring-param-strict-body.js
@@ -0,0 +1,113 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/object-destructuring-param-strict-body.case
+// - src/function-forms/syntax/async-gen-func-expr.template
+/*---
+description: ObjectBindingPattern and Use Strict Directive are not allowed to coexist for the same function. (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [rest-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.4 Static Semantics: IsSimpleParameterList
+
+    BindingElement : BindingPattern
+
+    1. Return false.
+
+    14.1.2 Static Semantics: Early Errors
+
+    FunctionDeclaration : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+    FunctionDeclaration : function ( FormalParameters ) { FunctionBody }
+    FunctionExpression : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.2.1 Static Semantics: Early Errors
+
+    ArrowFunction : ArrowParameters => ConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of ConciseBody is true and
+      IsSimpleParameterList of ArrowParameters is false.
+
+    14.3.1 Static Semantics: Early Errors
+
+    MethodDefinition : PropertyName ( UniqueFormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    MethodDefinition : set PropertyName ( PropertySetParameterList ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of PropertySetParameterList is false.
+
+    14.4.1 Static Semantics: Early Errors
+
+    GeneratorMethod : * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    GeneratorDeclaration : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+    GeneratorDeclaration : function * ( FormalParameters ) { GeneratorBody }
+    GeneratorExpression : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    14.5.1 Static Semantics: Early Errors
+
+    AsyncGeneratorMethod : async * PropertyName ( UniqueFormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncGeneratorDeclaration : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorDeclaration : async function * ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorExpression : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.7.1 Static Semantics: Early Errors
+
+    AsyncMethod : async PropertyName ( UniqueFormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncFunctionDeclaration : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionDeclaration : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.8.1 Static Semantics: Early Errors
+
+    AsyncArrowFunction : CoverCallExpressionAndAsyncArrowHead => AsyncConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncConciseBody is true and
+      IsSimpleParameterList of CoverCallExpressionAndAsyncArrowHead is false.
+
+---*/
+$DONOTEVALUATE();
+
+
+0, async function*({property}) {
+  "use strict";
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/params-trailing-comma-multiple.js b/js/src/tests/test262/language/expressions/async-generator/params-trailing-comma-multiple.js
new file mode 100644
index 0000000000..4420b0920c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/params-trailing-comma-multiple.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/params-trailing-comma-multiple.case
+// - src/function-forms/default/async-gen-func-expr.template
+/*---
+description: A trailing comma should not increase the respective length, using multiple parameters (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] : FormalParameterList[?Yield, ?Await] ,
+---*/
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function*(a, b,) {
+  assert.sameValue(a, 42);
+  assert.sameValue(b, 39);
+  callCount = callCount + 1;
+};
+
+ref(42, 39, 1).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+assert.sameValue(ref.length, 2, 'length is properly set');
diff --git a/js/src/tests/test262/language/expressions/async-generator/params-trailing-comma-single.js b/js/src/tests/test262/language/expressions/async-generator/params-trailing-comma-single.js
new file mode 100644
index 0000000000..9b6b8e373c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/params-trailing-comma-single.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/params-trailing-comma-single.case
+// - src/function-forms/default/async-gen-func-expr.template
+/*---
+description: A trailing comma should not increase the respective length, using a single parameter (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] : FormalParameterList[?Yield, ?Await] ,
+---*/
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function*(a,) {
+  assert.sameValue(a, 42);
+  callCount = callCount + 1;
+};
+
+ref(42, 39).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+assert.sameValue(ref.length, 1, 'length is properly set');
diff --git a/js/src/tests/test262/language/expressions/async-generator/rest-param-strict-body.js b/js/src/tests/test262/language/expressions/async-generator/rest-param-strict-body.js
new file mode 100644
index 0000000000..e65fd4f7c6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/rest-param-strict-body.js
@@ -0,0 +1,113 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/rest-param-strict-body.case
+// - src/function-forms/syntax/async-gen-func-expr.template
+/*---
+description: RestParameter and Use Strict Directive are not allowed to coexist for the same function. (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [rest-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    14.1.13 Static Semantics: IsSimpleParameterList
+
+    FormalParameters : FormalParameterList , FunctionRestParameter
+
+    1. Return false.
+
+    14.1.2 Static Semantics: Early Errors
+
+    FunctionDeclaration : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+    FunctionDeclaration : function ( FormalParameters ) { FunctionBody }
+    FunctionExpression : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.2.1 Static Semantics: Early Errors
+
+    ArrowFunction : ArrowParameters => ConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of ConciseBody is true and
+      IsSimpleParameterList of ArrowParameters is false.
+
+    14.3.1 Static Semantics: Early Errors
+
+    MethodDefinition : PropertyName ( UniqueFormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    MethodDefinition : set PropertyName ( PropertySetParameterList ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of PropertySetParameterList is false.
+
+    14.4.1 Static Semantics: Early Errors
+
+    GeneratorMethod : * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    GeneratorDeclaration : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+    GeneratorDeclaration : function * ( FormalParameters ) { GeneratorBody }
+    GeneratorExpression : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    14.5.1 Static Semantics: Early Errors
+
+    AsyncGeneratorMethod : async * PropertyName ( UniqueFormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncGeneratorDeclaration : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorDeclaration : async function * ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorExpression : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.7.1 Static Semantics: Early Errors
+
+    AsyncMethod : async PropertyName ( UniqueFormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncFunctionDeclaration : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionDeclaration : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.8.1 Static Semantics: Early Errors
+
+    AsyncArrowFunction : CoverCallExpressionAndAsyncArrowHead => AsyncConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncConciseBody is true and
+      IsSimpleParameterList of CoverCallExpressionAndAsyncArrowHead is false.
+
+---*/
+$DONOTEVALUATE();
+
+
+0, async function*(a,...rest) {
+  "use strict";
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/rest-params-trailing-comma-early-error.js b/js/src/tests/test262/language/expressions/async-generator/rest-params-trailing-comma-early-error.js
new file mode 100644
index 0000000000..d0ab701557
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/rest-params-trailing-comma-early-error.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/rest-params-trailing-comma-early-error.case
+// - src/function-forms/syntax/async-gen-func-expr.template
+/*---
+description: It's a syntax error if a FunctionRestParameter is followed by a trailing comma (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] :
+        [empty]
+        FunctionRestParameter[?Yield, ?Await]
+        FormalParameterList[?Yield, ?Await]
+        FormalParameterList[?Yield, ?Await] ,
+        FormalParameterList[?Yield, ?Await] , FunctionRestParameter[?Yield, ?Await]
+---*/
+$DONOTEVALUATE();
+
+
+0, async function*(...a,) {
+  
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/shell.js b/js/src/tests/test262/language/expressions/async-generator/shell.js
new file mode 100644
index 0000000000..cf5a381e81
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/shell.js
@@ -0,0 +1,137 @@
+// GENERATED, DO NOT EDIT
+// file: asyncHelpers.js
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+description: |
+    A collection of assertion and wrapper functions for testing asynchronous built-ins.
+defines: [asyncTest]
+---*/
+
+function asyncTest(testFunc) {
+  if (!Object.hasOwn(globalThis, "$DONE")) {
+    throw new Test262Error("asyncTest called without async flag");
+  }
+  if (typeof testFunc !== "function") {
+    $DONE(new Test262Error("asyncTest called with non-function argument"));
+    return;
+  }
+  try {
+    testFunc().then(
+      function () {
+        $DONE();
+      },
+      function (error) {
+        $DONE(error);
+      }
+    );
+  } catch (syncError) {
+    $DONE(syncError);
+  }
+}
+
+assert.throwsAsync = async function (expectedErrorConstructor, func, message) {
+  var innerThenable;
+  if (message === undefined) {
+    message = "";
+  } else {
+    message += " ";
+  }
+  if (typeof func === "function") {
+    try {
+      innerThenable = func();
+      if (
+        innerThenable === null ||
+        typeof innerThenable !== "object" ||
+        typeof innerThenable.then !== "function"
+      ) {
+        message +=
+          "Expected to obtain an inner promise that would reject with a" +
+          expectedErrorConstructor.name +
+          " but result was not a thenable";
+        throw new Test262Error(message);
+      }
+    } catch (thrown) {
+      message +=
+        "Expected a " +
+        expectedErrorConstructor.name +
+        " to be thrown asynchronously but an exception was thrown synchronously while obtaining the inner promise";
+      throw new Test262Error(message);
+    }
+  } else {
+    message +=
+      "assert.throwsAsync called with an argument that is not a function";
+    throw new Test262Error(message);
+  }
+
+  try {
+    return innerThenable.then(
+      function () {
+        message +=
+          "Expected a " +
+          expectedErrorConstructor.name +
+          " to be thrown asynchronously but no exception was thrown at all";
+        throw new Test262Error(message);
+      },
+      function (thrown) {
+        var expectedName, actualName;
+        if (typeof thrown !== "object" || thrown === null) {
+          message += "Thrown value was not an object!";
+          throw new Test262Error(message);
+        } else if (thrown.constructor !== expectedErrorConstructor) {
+          expectedName = expectedErrorConstructor.name;
+          actualName = thrown.constructor.name;
+          if (expectedName === actualName) {
+            message +=
+              "Expected a " +
+              expectedName +
+              " but got a different error constructor with the same name";
+          } else {
+            message +=
+              "Expected a " + expectedName + " but got a " + actualName;
+          }
+          throw new Test262Error(message);
+        }
+      }
+    );
+  } catch (thrown) {
+    if (typeof thrown !== "object" || thrown === null) {
+      message +=
+        "Expected a " +
+        expectedErrorConstructor.name +
+        " to be thrown asynchronously but innerThenable synchronously threw a value that was not an object ";
+    } else {
+      message +=
+        "Expected a " +
+        expectedErrorConstructor.name +
+        " to be thrown asynchronously but a " +
+        thrown.constructor.name +
+        " was thrown synchronously";
+    }
+    throw new Test262Error(message);
+  }
+};
+
+// file: isConstructor.js
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: |
+    Test if a given function is a constructor function.
+defines: [isConstructor]
+features: [Reflect.construct]
+---*/
+
+function isConstructor(f) {
+    if (typeof f !== "function") {
+      throw new Test262Error("isConstructor invoked with a non-function value");
+    }
+
+    try {
+        Reflect.construct(function(){}, [], f);
+    } catch (e) {
+        return false;
+    }
+    return true;
+}
diff --git a/js/src/tests/test262/language/expressions/async-generator/unscopables-with-in-nested-fn.js b/js/src/tests/test262/language/expressions/async-generator/unscopables-with-in-nested-fn.js
new file mode 100644
index 0000000000..fb34ee1120
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/unscopables-with-in-nested-fn.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/unscopables-with-in-nested-fn.case
+// - src/function-forms/default/async-gen-func-expr.template
+/*---
+description: Symbol.unscopables behavior across scope boundaries (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [globalThis, Symbol.unscopables, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    ...
+    Let envRec be lex's EnvironmentRecord.
+    Let exists be ? envRec.HasBinding(name).
+
+    HasBinding
+
+    ...
+    If the withEnvironment flag of envRec is false, return true.
+    Let unscopables be ? Get(bindings, @@unscopables).
+    If Type(unscopables) is Object, then
+       Let blocked be ToBoolean(? Get(unscopables, N)).
+       If blocked is true, return false.
+
+    (The `with` Statement) Runtime Semantics: Evaluation
+
+    ...
+    Set the withEnvironment flag of newEnv’s EnvironmentRecord to true.
+    ...
+
+---*/
+let count = 0;
+var v = 1;
+globalThis[Symbol.unscopables] = {
+  v: true,
+};
+
+{
+  count++;
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function*(x) {
+  (function() {
+    count++;
+    with (globalThis) {
+      count++;
+      assert.sameValue(v, 1, 'The value of `v` is 1');
+    }
+  })();
+  (function() {
+    count++;
+    var v = x;
+    with (globalThis) {
+      count++;
+      assert.sameValue(v, 10, 'The value of `v` is 10');
+      v = 20;
+    }
+    assert.sameValue(v, 20, 'The value of `v` is 20');
+    assert.sameValue(globalThis.v, 1, 'The value of globalThis.v is 1');
+  })();
+  assert.sameValue(v, 1, 'The value of `v` is 1');
+  assert.sameValue(globalThis.v, 1, 'The value of globalThis.v is 1');
+  callCount = callCount + 1;
+};
+
+ref(10).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+  count++;
+}
+assert.sameValue(count, 6, 'The value of `count` is 6');
diff --git a/js/src/tests/test262/language/expressions/async-generator/unscopables-with.js b/js/src/tests/test262/language/expressions/async-generator/unscopables-with.js
new file mode 100644
index 0000000000..c81b74fc1d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/unscopables-with.js
@@ -0,0 +1,77 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/unscopables-with.case
+// - src/function-forms/default/async-gen-func-expr.template
+/*---
+description: Symbol.unscopables behavior across scope boundaries (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [globalThis, Symbol.unscopables, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    ...
+    Let envRec be lex's EnvironmentRecord.
+    Let exists be ? envRec.HasBinding(name).
+
+    HasBinding
+
+    ...
+    If the withEnvironment flag of envRec is false, return true.
+    Let unscopables be ? Get(bindings, @@unscopables).
+    If Type(unscopables) is Object, then
+       Let blocked be ToBoolean(? Get(unscopables, N)).
+       If blocked is true, return false.
+
+    (The `with` Statement) Runtime Semantics: Evaluation
+
+    ...
+    Set the withEnvironment flag of newEnv’s EnvironmentRecord to true.
+    ...
+
+---*/
+let count = 0;
+var v = 1;
+globalThis[Symbol.unscopables] = {
+  v: true,
+};
+
+{
+  count++;
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+var ref;
+ref = async function*(x) {
+  count++;
+  with (globalThis) {
+    count++;
+    assert.sameValue(v, undefined, 'The value of `v` is expected to equal `undefined`');
+  }
+  count++;
+  var v = x;
+  with (globalThis) {
+    count++;
+    assert.sameValue(v, 10, 'The value of `v` is 10');
+    v = 20;
+  }
+  assert.sameValue(v, 20, 'The value of `v` is 20');
+  assert.sameValue(globalThis.v, 1, 'The value of globalThis.v is 1');
+  callCount = callCount + 1;
+};
+
+ref(10).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+  count++;
+}
+assert.sameValue(count, 6, 'The value of `count` is 6');
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-as-binding-identifier-escaped.js b/js/src/tests/test262/language/expressions/async-generator/yield-as-binding-identifier-escaped.js
new file mode 100644
index 0000000000..1b7a3d5c70
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-as-binding-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-binding-identifier-escaped.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  var yi\u0065ld;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-as-binding-identifier.js b/js/src/tests/test262/language/expressions/async-generator/yield-as-binding-identifier.js
new file mode 100644
index 0000000000..b83d30181e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-as-binding-identifier.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-binding-identifier.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  var yield;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-as-identifier-reference-escaped.js b/js/src/tests/test262/language/expressions/async-generator/yield-as-identifier-reference-escaped.js
new file mode 100644
index 0000000000..f03c691dce
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-as-identifier-reference-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-identifier-reference-escaped.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  void yi\u0065ld;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-as-identifier-reference.js b/js/src/tests/test262/language/expressions/async-generator/yield-as-identifier-reference.js
new file mode 100644
index 0000000000..3db9c366ce
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-as-identifier-reference.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-identifier-reference.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  void yield;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-as-label-identifier-escaped.js b/js/src/tests/test262/language/expressions/async-generator/yield-as-label-identifier-escaped.js
new file mode 100644
index 0000000000..918c83ca7c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-as-label-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-label-identifier-escaped.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a label identifier. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  yi\u0065ld: ;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-as-label-identifier.js b/js/src/tests/test262/language/expressions/async-generator/yield-as-label-identifier.js
new file mode 100644
index 0000000000..581fd97828
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-as-label-identifier.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-label-identifier.case
+// - src/async-generators/syntax/async-expression.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a label identifier. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+var gen = async function *() {
+  yield: ;
+};
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-identifier-non-strict.js b/js/src/tests/test262/language/expressions/async-generator/yield-identifier-non-strict.js
new file mode 100644
index 0000000000..6109ef68dd
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-identifier-non-strict.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-identifier-non-strict.case
+// - src/async-generators/non-strict/async-expression.template
+/*---
+description: Use of yield as a valid identifier in a function body inside a generator body in non strict mode (Async generator expression - valid for non-strict only cases)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  return (function(arg) {
+      var yield = arg + 1;
+      return yield;
+    }(yield))
+};
+
+var iter = gen();
+
+var item = iter.next();
+
+item.then(({ done, value }) => {
+  assert.sameValue(done, false);
+  assert.sameValue(value, undefined);
+});
+
+item = iter.next(42);
+
+item.then(({ done, value }) => {
+  assert.sameValue(done, true);
+  assert.sameValue(value, 43);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-identifier-spread-non-strict.js b/js/src/tests/test262/language/expressions/async-generator/yield-identifier-spread-non-strict.js
new file mode 100644
index 0000000000..07db53e691
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-identifier-spread-non-strict.js
@@ -0,0 +1,64 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-identifier-spread-non-strict.case
+// - src/async-generators/non-strict/async-expression.template
+/*---
+description: Mixed use of object spread and yield as a valid identifier in a function body inside a generator body in non strict mode (Async generator expression - valid for non-strict only cases)
+esid: prod-AsyncGeneratorExpression
+features: [object-spread, Symbol, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Spread Properties
+
+    PropertyDefinition[Yield]:
+      (...)
+      ...AssignmentExpression[In, ?Yield]
+
+---*/
+var s = Symbol('s');
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield {
+       ...yield yield,
+       ...(function(arg) {
+          var yield = arg;
+          return {...yield};
+       }(yield)),
+       ...yield,
+    }
+};
+
+var iter = gen();
+
+var iter = gen();
+
+iter.next();
+iter.next();
+iter.next({ x: 10, a: 0, b: 0, [s]: 1 });
+iter.next({ y: 20, a: 1, b: 1, [s]: 42 });
+var item = iter.next({ z: 30, b: 2 });
+
+item.then(({ done, value }) => {
+  assert.sameValue(done, false);
+  assert.sameValue(value.x, 10);
+  assert.sameValue(value.y, 20);
+  assert.sameValue(value.z, 30);
+  assert.sameValue(value.a, 1);
+  assert.sameValue(value.b, 2);
+  assert.sameValue(value[s], 42);
+  assert.sameValue(Object.keys(value).length, 5);
+  assert(Object.prototype.hasOwnProperty.call(value, s), "s is an own property");
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-identifier-spread-strict-strict.js b/js/src/tests/test262/language/expressions/async-generator/yield-identifier-spread-strict-strict.js
new file mode 100644
index 0000000000..80d10cb584
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-identifier-spread-strict-strict.js
@@ -0,0 +1,48 @@
+// |reftest| error:SyntaxError
+'use strict';
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-identifier-spread-strict.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: It's an early error if the AssignmentExpression is a function body with yield as an identifier in strict mode. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [object-spread, async-iteration]
+flags: [generated, onlyStrict]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Spread Properties
+
+    PropertyDefinition[Yield]:
+      (...)
+      ...AssignmentExpression[In, ?Yield]
+
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  return {
+       ...(function() {
+          var yield;
+          throw new Test262Error();
+       }()),
+    }
+};
+
+var iter = gen();
+
+
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-identifier-strict-strict.js b/js/src/tests/test262/language/expressions/async-generator/yield-identifier-strict-strict.js
new file mode 100644
index 0000000000..619b331edf
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-identifier-strict-strict.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+'use strict';
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-identifier-strict.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: It's an early error if the generator body has another function body with yield as an identifier in strict mode. (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, onlyStrict]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  (function() {
+      var yield;
+      throw new Test262Error();
+    }())
+};
+
+var iter = gen();
+
+
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-catch.js b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-catch.js
new file mode 100644
index 0000000000..c6bc275429
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-catch.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-catch.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: yield Promise.reject(value) is treated as throw value (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield Promise.reject(error);
+  yield "unreachable";
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}).catch(rejectValue => {
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+});
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-for-await-of-async-iterator.js b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-for-await-of-async-iterator.js
new file mode 100644
index 0000000000..b52d02c782
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-for-await-of-async-iterator.js
@@ -0,0 +1,50 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-for-await-of-async-iterator.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: yield * [Promise.reject(value)] is treated as throw value (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+async function * readFile() {
+  yield Promise.reject(error);
+  yield "unreachable";
+}
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  for await (let line of readFile()) {
+    yield line;
+  }
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}, rejectValue => {
+
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-for-await-of-sync-iterator.js b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-for-await-of-sync-iterator.js
new file mode 100644
index 0000000000..63c5e9d729
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-for-await-of-sync-iterator.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-for-await-of-sync-iterator.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: yield Promise.reject(value) in for-await-of is treated as throw value (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+let iterable = [
+  Promise.reject(error),
+  "unreachable"
+];
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  for await (let value of iterable) {
+    yield value;
+  }
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}, rejectValue => {
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-yield-star-async-iterator.js b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-yield-star-async-iterator.js
new file mode 100644
index 0000000000..56dbf03163
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-yield-star-async-iterator.js
@@ -0,0 +1,48 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-yield-star-async-iterator.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: yield * (async iterator) is treated as throw value (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+async function * readFile() {
+  yield Promise.reject(error);
+  yield "unreachable";
+}
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield * readFile();
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}, rejectValue => {
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+}, $DONE).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-yield-star-sync-iterator.js b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-yield-star-sync-iterator.js
new file mode 100644
index 0000000000..4894df5495
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next-yield-star-sync-iterator.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-yield-star-sync-iterator.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: yield * (async iterator) is treated as throw value (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+let iterable = [
+  Promise.reject(error),
+  "unreachable"
+];
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield * iterable;
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}, rejectValue => {
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next.js b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next.js
new file mode 100644
index 0000000000..0d1b1e641e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-promise-reject-next.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: yield Promise.reject(value) is treated as throw value (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield Promise.reject(error);
+  yield "unreachable";
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}, rejectValue => {
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-spread-arr-multiple.js b/js/src/tests/test262/language/expressions/async-generator/yield-spread-arr-multiple.js
new file mode 100644
index 0000000000..4dbf565258
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-spread-arr-multiple.js
@@ -0,0 +1,50 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-spread-arr-multiple.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Use yield value in a array spread position (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+includes: [compareArray.js]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Array Initializer
+
+    SpreadElement[Yield, Await]:
+      ...AssignmentExpression[+In, ?Yield, ?Await]
+
+---*/
+var arr = ['a', 'b', 'c'];
+var item;
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield [...yield yield];
+};
+
+var iter = gen();
+
+iter.next(false);
+item = iter.next(['a', 'b', 'c']);
+
+item.then(({ done, value }) => {
+  item = iter.next(value);
+
+  item.then(({ done, value }) => {
+    assert.compareArray(value, arr);
+    assert.sameValue(done, false);
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-spread-arr-single.js b/js/src/tests/test262/language/expressions/async-generator/yield-spread-arr-single.js
new file mode 100644
index 0000000000..fbec5ea757
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-spread-arr-single.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-spread-arr-single.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Use yield value in a array spread position (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Array Initializer
+
+    SpreadElement[Yield, Await]:
+      ...AssignmentExpression[+In, ?Yield, ?Await]
+
+---*/
+var arr = ['a', 'b', 'c'];
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield [...yield];
+};
+
+var iter = gen();
+
+iter.next(false);
+var item = iter.next(arr);
+
+item.then(({ done, value }) => {
+  assert.notSameValue(value, arr, 'value is a new array');
+  assert(Array.isArray(value), 'value is an Array exotic object');
+  assert.sameValue(value.length, 3)
+  assert.sameValue(value[0], 'a');
+  assert.sameValue(value[1], 'b');
+  assert.sameValue(value[2], 'c');
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-spread-obj.js b/js/src/tests/test262/language/expressions/async-generator/yield-spread-obj.js
new file mode 100644
index 0000000000..d397a95d38
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-spread-obj.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-spread-obj.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Use yield value in a object spread position (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [object-spread, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Spread Properties
+
+    PropertyDefinition[Yield]:
+      (...)
+      ...AssignmentExpression[In, ?Yield]
+
+---*/
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield {
+      ...yield,
+      y: 1,
+      ...yield yield,
+    };
+};
+
+var iter = gen();
+
+iter.next();
+iter.next({ x: 42 });
+iter.next({ x: 'lol' });
+var item = iter.next({ y: 39 });
+
+item.then(({ done, value }) => {
+  assert.sameValue(value.x, 42);
+  assert.sameValue(value.y, 39);
+  assert.sameValue(Object.keys(value).length, 2);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-async-next.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-async-next.js
new file mode 100644
index 0000000000..320a642ab0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-async-next.js
@@ -0,0 +1,219 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-async-next.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Execution order for yield* with async iterator and next() (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    
+---*/
+var log = [];
+var obj = {
+  get [Symbol.iterator]() {
+    log.push({ name: "get [Symbol.iterator]" });
+  },
+  get [Symbol.asyncIterator]() {
+    log.push({
+      name: "get [Symbol.asyncIterator]",
+      thisValue: this
+    });
+    return function() {
+      log.push({
+        name: "call [Symbol.asyncIterator]",
+        thisValue: this,
+        args: [...arguments]
+      });
+      var nextCount = 0;
+      return {
+        name: "asyncIterator",
+        get next() {
+          log.push({
+            name: "get next",
+            thisValue: this
+          });
+          return function() {
+            log.push({
+              name: "call next",
+              thisValue: this,
+              args: [...arguments]
+            });
+
+            nextCount++;
+            if (nextCount == 1) {
+              return {
+                name: "next-promise-1",
+                get then() {
+                  log.push({
+                    name: "get next then (1)",
+                    thisValue: this
+                  });
+                  return function(resolve) {
+                    log.push({
+                      name: "call next then (1)",
+                      thisValue: this,
+                      args: [...arguments]
+                    });
+
+                    resolve({
+                      name: "next-result-1",
+                      get value() {
+                        log.push({
+                          name: "get next value (1)",
+                          thisValue: this
+                        });
+                        return "next-value-1";
+                      },
+                      get done() {
+                        log.push({
+                          name: "get next done (1)",
+                          thisValue: this
+                        });
+                        return false;
+                      }
+                    });
+                  };
+                }
+              };
+            }
+
+            return {
+              name: "next-promise-2",
+              get then() {
+                log.push({
+                  name: "get next then (2)",
+                  thisValue: this
+                });
+                return function(resolve) {
+                  log.push({
+                    name: "call next then (2)",
+                    thisValue: this,
+                    args: [...arguments]
+                  });
+
+                  resolve({
+                    name: "next-result-2",
+                    get value() {
+                      log.push({
+                        name: "get next value (2)",
+                        thisValue: this
+                      });
+                      return "next-value-2";
+                    },
+                    get done() {
+                      log.push({
+                        name: "get next done (2)",
+                        thisValue: this
+                      });
+                      return true;
+                    }
+                  });
+                };
+              }
+            };
+          };
+        }
+      };
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    var v = yield* obj;
+    log.push({
+      name: "after yield*",
+      value: v
+    });
+    return "return-value";
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next("next-arg-1").then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get [Symbol.asyncIterator]");
+  assert.sameValue(log[1].thisValue, obj, "get [Symbol.asyncIterator] thisValue");
+
+  assert.sameValue(log[2].name, "call [Symbol.asyncIterator]");
+  assert.sameValue(log[2].thisValue, obj, "[Symbol.asyncIterator] thisValue");
+  assert.sameValue(log[2].args.length, 0, "[Symbol.asyncIterator] args.length");
+
+  assert.sameValue(log[3].name, "get next");
+  assert.sameValue(log[3].thisValue.name, "asyncIterator", "get next thisValue");
+
+  assert.sameValue(log[4].name, "call next");
+  assert.sameValue(log[4].thisValue.name, "asyncIterator", "next thisValue");
+  assert.sameValue(log[4].args.length, 1, "next args.length");
+  assert.sameValue(log[4].args[0], undefined, "next args[0]");
+
+  assert.sameValue(log[5].name, "get next then (1)");
+  assert.sameValue(log[5].thisValue.name, "next-promise-1", "get next then thisValue");
+
+  assert.sameValue(log[6].name, "call next then (1)");
+  assert.sameValue(log[6].thisValue.name, "next-promise-1", "next then thisValue");
+  assert.sameValue(log[6].args.length, 2, "next then args.length");
+  assert.sameValue(typeof log[6].args[0], "function", "next then args[0]");
+  assert.sameValue(typeof log[6].args[1], "function", "next then args[1]");
+
+  assert.sameValue(log[7].name, "get next done (1)");
+  assert.sameValue(log[7].thisValue.name, "next-result-1", "get next done thisValue");
+
+  assert.sameValue(log[8].name, "get next value (1)");
+  assert.sameValue(log[8].thisValue.name, "next-result-1", "get next value thisValue");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 9, "log.length");
+
+  iter.next("next-arg-2").then(v => {
+    assert.sameValue(log[9].name, "call next");
+    assert.sameValue(log[9].thisValue.name, "asyncIterator", "next thisValue");
+    assert.sameValue(log[9].args.length, 1, "next args.length");
+    assert.sameValue(log[9].args[0], "next-arg-2", "next args[0]");
+
+    assert.sameValue(log[10].name, "get next then (2)");
+    assert.sameValue(log[10].thisValue.name, "next-promise-2", "get next then thisValue");
+
+    assert.sameValue(log[11].name, "call next then (2)");
+    assert.sameValue(log[11].thisValue.name, "next-promise-2", "next then thisValue");
+    assert.sameValue(log[11].args.length, 2, "next then args.length");
+    assert.sameValue(typeof log[11].args[0], "function", "next then args[0]");
+    assert.sameValue(typeof log[11].args[1], "function", "next then args[1]");
+
+    assert.sameValue(log[12].name, "get next done (2)");
+    assert.sameValue(log[12].thisValue.name, "next-result-2", "get next done thisValue");
+
+    assert.sameValue(log[13].name, "get next value (2)");
+    assert.sameValue(log[13].thisValue.name, "next-result-2", "get next value thisValue");
+
+    assert.sameValue(log[14].name, "after yield*");
+    assert.sameValue(log[14].value, "next-value-2");
+
+    assert.sameValue(v.value, "return-value");
+    assert.sameValue(v.done, true);
+
+    assert.sameValue(log.length, 15, "log.length");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-async-return.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-async-return.js
new file mode 100644
index 0000000000..f3ffe4fc85
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-async-return.js
@@ -0,0 +1,235 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-async-return.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: execution order for yield* with async iterator and return() (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      c. Else,
+        i. Assert: received.[[Type]] is return.
+        ii. Let return be ? GetMethod(iterator, "return").
+        iii. If return is undefined, return Completion(received).
+        iv. Let innerReturnResult be ? Call(return, iterator, « received.[[Value]] »).
+        v. If generatorKind is async, then set innerReturnResult to ? Await(innerReturnResult).
+        ...
+        vii. Let done be ? IteratorComplete(innerReturnResult).
+        viii. If done is true, then
+             1. Let value be ? IteratorValue(innerReturnResult).
+             2. If generatorKind is async, then set value to ? Await(value).
+             3. Return Completion{[[Type]]: return, [[Value]]: value, [[Target]]: empty}.
+        ix. If generatorKind is async, then let received be AsyncGeneratorYield(? IteratorValue(innerResult)).
+        ...
+
+    AsyncGeneratorYield ( value )
+    ...
+    8. Return ! AsyncGeneratorResolve(generator, value, false).
+    ...
+
+---*/
+var log = [];
+var obj = {
+  [Symbol.asyncIterator]() {
+    var returnCount = 0;
+    return {
+      name: 'asyncIterator',
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get return() {
+        log.push({
+          name: "get return",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call return",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          returnCount++;
+          if (returnCount == 1) {
+            return {
+              name: "return-promise-1",
+              get then() {
+                log.push({
+                  name: "get return then (1)",
+                  thisValue: this
+                });
+                return function(resolve) {
+                  log.push({
+                    name: "call return then (1)",
+                    thisValue: this,
+                    args: [...arguments]
+                  });
+
+                  resolve({
+                    name: "return-result-1",
+                    get value() {
+                      log.push({
+                        name: "get return value (1)",
+                        thisValue: this
+                      });
+                      return "return-value-1";
+                    },
+                    get done() {
+                      log.push({
+                        name: "get return done (1)",
+                        thisValue: this
+                      });
+                      return false;
+                    }
+                  });
+                };
+              }
+            };
+          }
+
+          return {
+            name: "return-promise-2",
+            get then() {
+              log.push({
+                name: "get return then (2)",
+                thisValue: this
+              });
+              return function(resolve) {
+                log.push({
+                  name: "call return then (2)",
+                  thisValue: this,
+                  args: [...arguments]
+                });
+
+                resolve({
+                  name: "return-result-2",
+                  get value() {
+                    log.push({
+                      name: "get return value (2)",
+                      thisValue: this
+                    });
+                    return "return-value-2";
+                  },
+                  get done() {
+                    log.push({
+                      name: "get return done (2)",
+                      thisValue: this
+                    });
+                    return true;
+                  }
+                });
+              };
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    yield* obj;
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.return("return-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get return");
+    assert.sameValue(log[2].thisValue.name, "asyncIterator", "get return thisValue");
+
+    assert.sameValue(log[3].name, "call return");
+    assert.sameValue(log[3].thisValue.name, "asyncIterator", "return thisValue");
+    assert.sameValue(log[3].args.length, 1, "return args.length");
+    assert.sameValue(log[3].args[0], "return-arg-1", "return args[0]");
+
+    assert.sameValue(log[4].name, "get return then (1)");
+    assert.sameValue(log[4].thisValue.name, "return-promise-1", "get return then thisValue");
+
+    assert.sameValue(log[5].name, "call return then (1)");
+    assert.sameValue(log[5].thisValue.name, "return-promise-1", "return then thisValue");
+    assert.sameValue(log[5].args.length, 2, "return then args.length");
+    assert.sameValue(typeof log[5].args[0], "function", "return then args[0]");
+    assert.sameValue(typeof log[5].args[1], "function", "return then args[1]");
+
+    assert.sameValue(log[6].name, "get return done (1)");
+    assert.sameValue(log[6].thisValue.name, "return-result-1", "get return done thisValue");
+
+    assert.sameValue(log[7].name, "get return value (1)");
+    assert.sameValue(log[7].thisValue.name, "return-result-1", "get return value thisValue");
+
+    assert.sameValue(v.value, "return-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 8, "log.length");
+
+    iter.return("return-arg-2").then(v => {
+      assert.sameValue(log[8].name, "get return");
+      assert.sameValue(log[8].thisValue.name, "asyncIterator", "get return thisValue");
+
+      assert.sameValue(log[9].name, "call return");
+      assert.sameValue(log[9].thisValue.name, "asyncIterator", "return thisValue");
+      assert.sameValue(log[9].args.length, 1, "return args.length");
+      assert.sameValue(log[9].args[0], "return-arg-2", "return args[0]");
+
+      assert.sameValue(log[10].name, "get return then (2)");
+      assert.sameValue(log[10].thisValue.name, "return-promise-2", "get return then thisValue");
+
+      assert.sameValue(log[11].name, "call return then (2)");
+      assert.sameValue(log[11].thisValue.name, "return-promise-2", "return then thisValue");
+      assert.sameValue(log[11].args.length, 2, "return then args.length");
+      assert.sameValue(typeof log[11].args[0], "function", "return then args[0]");
+      assert.sameValue(typeof log[11].args[1], "function", "return then args[1]");
+
+      assert.sameValue(log[12].name, "get return done (2)");
+      assert.sameValue(log[12].thisValue.name, "return-result-2", "get return done thisValue");
+
+      assert.sameValue(log[13].name, "get return value (2)");
+      assert.sameValue(log[13].thisValue.name, "return-result-2", "get return value thisValue");
+
+      assert.sameValue(v.value, "return-value-2");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 14, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-async-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-async-throw.js
new file mode 100644
index 0000000000..aa6321eec2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-async-throw.js
@@ -0,0 +1,243 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-async-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: execution order for yield* with async iterator and throw() (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      b. Else if received.[[Type]] is throw, then
+        i. Let throw be ? GetMethod(iterator, "throw").
+        ii. If throw is not undefined, then
+          1. Let innerResult be ? Call(throw, iterator, « received.[[Value]] »).
+          2. If generatorKind is async, then set innerResult to ? Await(innerResult).
+          ...
+          5. Let done be ? IteratorComplete(innerResult).
+          6. If done is true, then
+            a. Let resultValue be Return ? IteratorValue(innerResult).
+            b. If generatorKind is async, then set resultValue to ? Await(resultValue).
+            c. Return resultValue.
+          7. If generatorKind is async, then let received be AsyncGeneratorYield(? IteratorValue(innerResult)).
+      ...
+
+    AsyncGeneratorYield ( value )
+
+    ...
+    8. Return ! AsyncGeneratorResolve(generator, value, false).
+    ...
+
+---*/
+var log = [];
+var obj = {
+  [Symbol.asyncIterator]() {
+    var throwCount = 0;
+    return {
+      name: "asyncIterator",
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get throw() {
+        log.push({
+          name: "get throw",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call throw",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          throwCount++;
+          if (throwCount == 1) {
+            return {
+              name: "throw-promise-1",
+              get then() {
+                log.push({
+                  name: "get throw then (1)",
+                  thisValue: this
+                });
+                return function(resolve) {
+                  log.push({
+                    name: "call throw then (1)",
+                    thisValue: this,
+                    args: [...arguments]
+                  });
+
+                  resolve({
+                    name: "throw-result-1",
+                    get value() {
+                      log.push({
+                        name: "get throw value (1)",
+                        thisValue: this
+                      });
+                      return "throw-value-1";
+                    },
+                    get done() {
+                      log.push({
+                        name: "get throw done (1)",
+                        thisValue: this
+                      });
+                      return false;
+                    }
+                  });
+                };
+              }
+            };
+          }
+
+          return {
+            name: "throw-promise-2",
+            get then() {
+              log.push({
+                name: "get throw then (2)",
+                thisValue: this
+              });
+              return function(resolve) {
+                log.push({
+                  name: "call throw then (2)",
+                  thisValue: this,
+                  args: [...arguments]
+                });
+
+                resolve({
+                  name: "throw-result-2",
+                  get value() {
+                    log.push({
+                      name: "get throw value (2)",
+                      thisValue: this
+                    });
+                    return "throw-value-2";
+                  },
+                  get done() {
+                    log.push({
+                      name: "get throw done (2)",
+                      thisValue: this
+                    });
+                    return true;
+                  }
+                });
+              };
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    var v = yield* obj;
+    log.push({
+      name: "after yield*",
+      value: v
+    });
+    return "return-value";
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.throw("throw-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get throw");
+    assert.sameValue(log[2].thisValue.name, "asyncIterator", "get throw thisValue");
+
+    assert.sameValue(log[3].name, "call throw");
+    assert.sameValue(log[3].thisValue.name, "asyncIterator", "throw thisValue");
+    assert.sameValue(log[3].args.length, 1, "throw args.length");
+    assert.sameValue(log[3].args[0], "throw-arg-1", "throw args[0]");
+
+    assert.sameValue(log[4].name, "get throw then (1)");
+    assert.sameValue(log[4].thisValue.name, "throw-promise-1", "get throw thisValue");
+
+    assert.sameValue(log[5].name, "call throw then (1)");
+    assert.sameValue(log[5].thisValue.name, "throw-promise-1", "throw thisValue");
+    assert.sameValue(log[5].args.length, 2, "throw then args.length");
+    assert.sameValue(typeof log[5].args[0], "function", "throw then args[0]");
+    assert.sameValue(typeof log[5].args[1], "function", "throw then args[1]");
+
+    assert.sameValue(log[6].name, "get throw done (1)");
+    assert.sameValue(log[6].thisValue.name, "throw-result-1", "get throw done thisValue");
+
+    assert.sameValue(log[7].name, "get throw value (1)");
+    assert.sameValue(log[7].thisValue.name, "throw-result-1", "get throw value thisValue");
+
+    assert.sameValue(v.value, "throw-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 8, "log.length");
+
+    iter.throw("throw-arg-2").then(v => {
+      assert.sameValue(log[8].name, "get throw");
+      assert.sameValue(log[8].thisValue.name, "asyncIterator", "get throw thisValue");
+
+      assert.sameValue(log[9].name, "call throw");
+      assert.sameValue(log[9].thisValue.name, "asyncIterator", "throw thisValue");
+      assert.sameValue(log[9].args.length, 1, "throw args.length");
+      assert.sameValue(log[9].args[0], "throw-arg-2", "throw args[0]");
+
+      assert.sameValue(log[10].name, "get throw then (2)");
+      assert.sameValue(log[10].thisValue.name, "throw-promise-2", "get throw thisValue");
+
+      assert.sameValue(log[11].name, "call throw then (2)");
+      assert.sameValue(log[11].thisValue.name, "throw-promise-2", "throw thisValue");
+      assert.sameValue(log[11].args.length, 2, "throw then args.length");
+      assert.sameValue(typeof log[11].args[0], "function", "throw then args[0]");
+      assert.sameValue(typeof log[11].args[1], "function", "throw then args[1]");
+
+      assert.sameValue(log[12].name, "get throw done (2)");
+      assert.sameValue(log[12].thisValue.name, "throw-result-2", "get throw done thisValue");
+
+      assert.sameValue(log[13].name, "get throw value (2)");
+      assert.sameValue(log[13].thisValue.name, "throw-result-2", "get throw value thisValue");
+
+      assert.sameValue(log[14].name, "after yield*");
+      assert.sameValue(log[14].value, "throw-value-2");
+
+      assert.sameValue(v.value, "return-value");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 15, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-expr-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-expr-abrupt.js
new file mode 100644
index 0000000000..a0ea9df5f0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-expr-abrupt.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-expr-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Abrupt completion while getting yield* operand (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    ...
+
+---*/
+var obj = {};
+var abrupt = function() {
+  throw obj;
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* abrupt();
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, obj, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-get-abrupt.js
new file mode 100644
index 0000000000..680e212d9b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-get-abrupt.js
@@ -0,0 +1,74 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-get-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Abrupt completion while getting [Symbol.asyncIterator] (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  get [Symbol.asyncIterator]() {
+    throw reason;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-boolean-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-boolean-throw.js
new file mode 100644
index 0000000000..91b1890579
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-boolean-throw.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-not-callable-boolean-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (boolean) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    3. If func is either undefined or null, return undefined.
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]: false
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-number-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-number-throw.js
new file mode 100644
index 0000000000..c9085eccde
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-number-throw.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-not-callable-number-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (number) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    3. If func is either undefined or null, return undefined.
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]: 0
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-object-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-object-throw.js
new file mode 100644
index 0000000000..87b20d1267
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-object-throw.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-not-callable-object-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (object) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    3. If func is either undefined or null, return undefined.
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]: {}
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-string-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-string-throw.js
new file mode 100644
index 0000000000..8cea57851b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-string-throw.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-not-callable-string-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (string) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    3. If func is either undefined or null, return undefined.
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]: ''
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-symbol-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-symbol-throw.js
new file mode 100644
index 0000000000..90088427c3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-not-callable-symbol-throw.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-not-callable-symbol-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (symbol) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    3. If func is either undefined or null, return undefined.
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]: Symbol.asyncIterator
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-null-sync-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-null-sync-get-abrupt.js
new file mode 100644
index 0000000000..9815973073
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-null-sync-get-abrupt.js
@@ -0,0 +1,79 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-null-sync-get-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Abrupt completion while getting @@iterator after null @@asyncIterator (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+
+---*/
+var calls = 0;
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw reason;
+  },
+  get [Symbol.asyncIterator]() {
+    calls += 1;
+    return null;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, 'reject reason');
+  assert.sameValue(calls, 1);
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-return-method-is-null.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-return-method-is-null.js
new file mode 100644
index 0000000000..3442f40923
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-return-method-is-null.js
@@ -0,0 +1,56 @@
+// |reftest| async
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-generator-function-definitions-runtime-semantics-evaluation
+description: >
+  If iterator's "return" method is `null`,
+  received completion is forwarded to the runtime.
+info: |
+  YieldExpression : yield * AssignmentExpression
+
+  [...]
+  7. Repeat,
+    [...]
+    c. Else,
+      i. Assert: received.[[Type]] is return.
+      ii. Let return be ? GetMethod(iterator, "return").
+      iii. If return is undefined, then
+        [...]
+        2. Return Completion(received).
+
+  GetMethod ( V, P )
+
+  [...]
+  2. Let func be ? GetV(V, P).
+  3. If func is either undefined or null, return undefined.
+features: [Symbol.asyncIterator, async-iteration]
+flags: [async]
+---*/
+
+var returnGets = 0;
+var asyncIterable = {
+  [Symbol.asyncIterator]: function() {
+    return this;
+  },
+  next: function() {
+    return {value: 1, done: false};
+  },
+  get return() {
+    returnGets += 1;
+    return null;
+  },
+};
+
+async function* asyncGenerator() {
+  yield* asyncIterable;
+}
+
+var asyncIterator = asyncGenerator();
+asyncIterator.next().then(function() {
+  return asyncIterator.return(2).then(function(result) {
+    assert.sameValue(result.value, 2);
+    assert.sameValue(result.done, true);
+    assert.sameValue(returnGets, 1);
+  });
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-abrupt.js
new file mode 100644
index 0000000000..3375e618d8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-abrupt.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Abrupt completion while calling [Symbol.asyncIterator] (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    throw reason;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-boolean-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-boolean-throw.js
new file mode 100644
index 0000000000..e56a3da991
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-boolean-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-boolean-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - boolean (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return true;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-null-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-null-throw.js
new file mode 100644
index 0000000000..45a5ee2896
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-null-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-null-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - null (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return null;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-number-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-number-throw.js
new file mode 100644
index 0000000000..51ce6dc606
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-number-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-number-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - number (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return 42;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-string-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-string-throw.js
new file mode 100644
index 0000000000..14930e0820
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-string-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-string-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - string (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return '42';
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-symbol-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-symbol-throw.js
new file mode 100644
index 0000000000..3c507a4c0c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-symbol-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-symbol-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - symbol (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return Symbol.asyncIterator;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-undefined-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-undefined-throw.js
new file mode 100644
index 0000000000..9172c549ba
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-returns-undefined-throw.js
@@ -0,0 +1,70 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-returns-undefined-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - undefined (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+    ...
+    6. Let iterator be ? Call(method, obj).
+    7. If Type(iterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return undefined;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-throw-method-is-null.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-throw-method-is-null.js
new file mode 100644
index 0000000000..d913b05c5d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-throw-method-is-null.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-generator-function-definitions-runtime-semantics-evaluation
+description: >
+  If iterator's "throw" method is `null`,
+  AsyncIteratorClose is called before rising TypeError.
+info: |
+  YieldExpression : yield * AssignmentExpression
+
+  [...]
+  7. Repeat,
+    [...]
+    b. Else if received.[[Type]] is throw, then
+      i. Let throw be ? GetMethod(iterator, "throw").
+      ii. If throw is not undefined, then
+        [...]
+      iii. Else,
+        [...]
+        3. If generatorKind is async, perform ? AsyncIteratorClose(iteratorRecord, closeCompletion).
+        [...]
+        6. Throw a TypeError exception.
+
+  GetMethod ( V, P )
+
+  [...]
+  2. Let func be ? GetV(V, P).
+  3. If func is either undefined or null, return undefined.
+
+  AsyncIteratorClose ( iteratorRecord, completion )
+
+  [...]
+  4. Let innerResult be GetMethod(iterator, "return").
+  5. If innerResult.[[Type]] is normal, then
+    a. Let return be innerResult.[[Value]].
+    b. If return is undefined, return Completion(completion).
+features: [Symbol.asyncIterator, async-iteration]
+flags: [async]
+---*/
+
+var throwGets = 0;
+var returnGets = 0;
+var asyncIterable = {
+  [Symbol.asyncIterator]: function() {
+    return this;
+  },
+  next: function() {
+    return {value: 1, done: false};
+  },
+  get throw() {
+    throwGets += 1;
+    return null;
+  },
+  get return() {
+    returnGets += 1;
+  },
+};
+
+async function* asyncGenerator() {
+  yield* asyncIterable;
+}
+
+var asyncIterator = asyncGenerator();
+asyncIterator.next().then(function() {
+  return asyncIterator.throw();
+}).then(function(result) {
+  throw new Test262Error("Promise should be rejected, got: " + result.value);
+}, function(err) {
+  assert.sameValue(err.constructor, TypeError);
+  assert.sameValue(throwGets, 1);
+  assert.sameValue(returnGets, 1);
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-undefined-sync-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-undefined-sync-get-abrupt.js
new file mode 100644
index 0000000000..b23681d778
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-async-undefined-sync-get-abrupt.js
@@ -0,0 +1,79 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-async-undefined-sync-get-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Abrupt completion while getting @@iterator after undefined @@asyncIterator (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+
+---*/
+var calls = 0;
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw reason;
+  },
+  get [Symbol.asyncIterator]() {
+    calls += 1;
+    return undefined;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, 'reject reason');
+  assert.sameValue(calls, 1);
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-get-abrupt.js
new file mode 100644
index 0000000000..654bfb3e2f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-get-abrupt.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-get-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Abrupt completion while getting [Symbol.iterator] (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw reason;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-boolean-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-boolean-throw.js
new file mode 100644
index 0000000000..d14d4869c8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-boolean-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-not-callable-boolean-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (boolean) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]: false
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-number-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-number-throw.js
new file mode 100644
index 0000000000..094a4f23e5
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-number-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-not-callable-number-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (number) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]: 0
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-object-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-object-throw.js
new file mode 100644
index 0000000000..6bff6abde4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-object-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-not-callable-object-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (object) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]: {}
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-string-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-string-throw.js
new file mode 100644
index 0000000000..bbf7743722
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-string-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-not-callable-string-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (string) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]: ''
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-symbol-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-symbol-throw.js
new file mode 100644
index 0000000000..dd005edf1f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-not-callable-symbol-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-not-callable-symbol-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (symbol) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+    ...
+
+    GetMethod ( V, P )
+
+    ...
+    2. Let func be ? GetV(V, P).
+    ...
+    4. If IsCallable(func) is false, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]: Symbol.iterator
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-abrupt.js
new file mode 100644
index 0000000000..6dbd5d7c24
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-abrupt.js
@@ -0,0 +1,67 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Abrupt completion while calling [Symbol.iterator] (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  [Symbol.iterator]() {
+    throw reason;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-boolean-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-boolean-throw.js
new file mode 100644
index 0000000000..488e1c77e8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-boolean-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-boolean-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.iterator]() - boolean (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return true;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-null-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-null-throw.js
new file mode 100644
index 0000000000..1d4d0bdfc9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-null-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-null-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.iterator]() - null (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return null;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-number-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-number-throw.js
new file mode 100644
index 0000000000..67753254d5
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-number-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-number-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.iterator]() - number (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return 0;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-string-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-string-throw.js
new file mode 100644
index 0000000000..184d6ecc6d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-string-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-string-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.iterator]() - string (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return '';
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-symbol-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-symbol-throw.js
new file mode 100644
index 0000000000..eaee7c8cf4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-symbol-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-symbol-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.iterator]() - symbol (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return Symbol.iterator;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-undefined-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-undefined-throw.js
new file mode 100644
index 0000000000..21e957e81c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-getiter-sync-returns-undefined-throw.js
@@ -0,0 +1,72 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-getiter-sync-returns-undefined-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Non object returned by [Symbol.iterator]() - undefined (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    CreateAsyncFromSyncIterator(syncIterator)
+
+    1. If Type(syncIterator) is not Object, throw a TypeError exception.
+    ...
+
+---*/
+var obj = {
+  [Symbol.iterator]() {
+    return undefined;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-call-done-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-call-done-get-abrupt.js
new file mode 100644
index 0000000000..f622c3c399
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-call-done-get-abrupt.js
@@ -0,0 +1,73 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-call-done-get-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Abrupt completion while getting done (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        ...
+        v. Let done be ? IteratorComplete(innerResult).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          get done() {
+            throw reason;
+          }
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-call-returns-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-call-returns-abrupt.js
new file mode 100644
index 0000000000..252379d854
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-call-returns-abrupt.js
@@ -0,0 +1,65 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-call-returns-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Abrupt completion while calling next (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        throw reason;
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-call-value-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-call-value-get-abrupt.js
new file mode 100644
index 0000000000..99ac29bdac
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-call-value-get-abrupt.js
@@ -0,0 +1,75 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-call-value-get-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Abrupt completion while getting value (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        ...
+        vi. If done is true, then
+           1. Return ? IteratorValue(innerResult).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          done: true,
+          get value() {
+            throw reason;
+          }
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-get-abrupt.js
new file mode 100644
index 0000000000..5d9a7c5f45
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-get-abrupt.js
@@ -0,0 +1,65 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-get-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Abrupt completion while getting next (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      get next() {
+        throw reason;
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-non-object-ignores-then.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-non-object-ignores-then.js
new file mode 100644
index 0000000000..63eef6716e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-non-object-ignores-then.js
@@ -0,0 +1,85 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-non-object-ignores-then.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: If next() value is not-object, do not access respective then property (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+
+---*/
+Number.prototype.then = function() {
+  throw new Test262Error('Number#then should not be used');
+};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return 42;
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, 'TypeError');
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-boolean-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-boolean-throw.js
new file mode 100644
index 0000000000..20193e3f47
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-boolean-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-boolean-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Not-callable next value in a yield star position - boolean (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: true
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-null-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-null-throw.js
new file mode 100644
index 0000000000..8bf77f19a8
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-null-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-null-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Not-callable next value in a yield star position - null (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: null
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-number-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-number-throw.js
new file mode 100644
index 0000000000..9d9301be19
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-number-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-number-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Not-callable next value in a yield star position - number (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: 42
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-object-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-object-throw.js
new file mode 100644
index 0000000000..cc1572642f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-object-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-object-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Not-callable next value in a yield star position - object (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: {}
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-string-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-string-throw.js
new file mode 100644
index 0000000000..e22a643088
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-string-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-string-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Not-callable next value in a yield star position - string (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: ''
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-symbol-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-symbol-throw.js
new file mode 100644
index 0000000000..4818e841ea
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-symbol-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-symbol-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Not-callable next value in a yield star position - symbol (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: Symbol('oi')
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-undefined-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-undefined-throw.js
new file mode 100644
index 0000000000..012882909b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-not-callable-undefined-throw.js
@@ -0,0 +1,62 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-not-callable-undefined-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Not-callable next value in a yield star position - undefined (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next: undefined
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v.constructor, TypeError, "TypeError");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-get-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-get-abrupt.js
new file mode 100644
index 0000000000..9b17fc3c26
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-get-abrupt.js
@@ -0,0 +1,89 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-get-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Return abrupt after getting next().then (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    8. Let then be Get(resolution, "then").
+    ...
+    10. Get thenAction be then.[[Value]].
+    ...
+    12. Perform EnqueueJob("PromiseJobs", PromiseResolveThenableJob, « promise,
+        resolution, thenAction »).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          get then() {
+            throw reason;
+          }
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, 'reject reason');
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-boolean-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-boolean-fulfillpromise.js
new file mode 100644
index 0000000000..d9ff3991a4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-boolean-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-boolean-fulfillpromise.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: FulfillPromise if next().then is not-callable (boolean) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: true,
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-null-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-null-fulfillpromise.js
new file mode 100644
index 0000000000..d74800050b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-null-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-null-fulfillpromise.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: FulfillPromise if next().then is not-callable (null) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: null,
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-number-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-number-fulfillpromise.js
new file mode 100644
index 0000000000..25b5c37d4a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-number-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-number-fulfillpromise.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: FulfillPromise if next().then is not-callable (number) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: 39,
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-object-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-object-fulfillpromise.js
new file mode 100644
index 0000000000..d6357f39bc
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-object-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-object-fulfillpromise.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: FulfillPromise if next().then is not-callable (object) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: {},
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-string-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-string-fulfillpromise.js
new file mode 100644
index 0000000000..91eb7c35a0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-string-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-string-fulfillpromise.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: FulfillPromise if next().then is not-callable (string) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: '',
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-symbol-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-symbol-fulfillpromise.js
new file mode 100644
index 0000000000..e1377fab5a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-symbol-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-symbol-fulfillpromise.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: FulfillPromise if next().then is not-callable (symbol) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: Symbol('oi'),
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-undefined-fulfillpromise.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-undefined-fulfillpromise.js
new file mode 100644
index 0000000000..6513d7bbce
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-non-callable-undefined-fulfillpromise.js
@@ -0,0 +1,83 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-non-callable-undefined-fulfillpromise.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: FulfillPromise if next().then is not-callable (undefined) (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        iv. If Type(innerResult) is not Object, throw a TypeError exception.
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    7. If Type(resolution) is not Object, then
+      a. Return FulfillPromise(promise, resolution).
+    8. Let then be Get(resolution, "then").
+    ...
+    11. If IsCallable(thenAction) is false, then
+      a. Return FulfillPromise(promise, resolution).
+    ...
+
+---*/
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then: undefined,
+          value: 42,
+          done: false
+        }
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(({ value, done }) => {
+  assert.sameValue(value, 42);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-returns-abrupt.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-returns-abrupt.js
new file mode 100644
index 0000000000..dc842b3e16
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-next-then-returns-abrupt.js
@@ -0,0 +1,89 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-next-then-returns-abrupt.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: Return abrupt after calling next().then (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+    ...
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+    ...
+
+    Await
+
+    ...
+    2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+    3. Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
+    ...
+
+    Promise Resolve Functions
+
+    ...
+    8. Let then be Get(resolution, "then").
+    ...
+    10. Get thenAction be then.[[Value]].
+    ...
+    12. Perform EnqueueJob("PromiseJobs", PromiseResolveThenableJob, « promise,
+        resolution, thenAction »).
+    ...
+
+---*/
+var reason = {};
+var obj = {
+  get [Symbol.iterator]() {
+    throw new Test262Error('it should not get Symbol.iterator');
+  },
+  [Symbol.asyncIterator]() {
+    return {
+      next() {
+        return {
+          then() {
+            throw reason;
+          }
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  yield* obj;
+    throw new Test262Error('abrupt completion closes iter');
+
+};
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, reason, 'reject reason');
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-sync-next.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-sync-next.js
new file mode 100644
index 0000000000..226e16aed7
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-sync-next.js
@@ -0,0 +1,222 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-sync-next.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: execution order for yield* with sync iterator and next() (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    2. Let value be ? GetValue(exprRef).
+    3. Let generatorKind be ! GetGeneratorKind().
+    4. Let iterator be ? GetIterator(value, generatorKind).
+    5. Let received be NormalCompletion(undefined).
+    6. Repeat
+      a. If received.[[Type]] is normal, then
+        i. Let innerResult be ? IteratorNext(iterator, received.[[Value]]).
+        ii. Let innerResult be ? Invoke(iterator, "next",
+            « received.[[Value]] »).
+        iii. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+        ...
+        v. Let done be ? IteratorComplete(innerResult).
+        vi. If done is true, then
+           1. Return ? IteratorValue(innerResult).
+        vii. Let received be GeneratorYield(innerResult).
+      ...
+
+    GetIterator ( obj [ , hint ] )
+
+    ...
+    3. If hint is async,
+      a. Set method to ? GetMethod(obj, @@asyncIterator).
+      b. If method is undefined,
+        i. Let syncMethod be ? GetMethod(obj, @@iterator).
+        ii. Let syncIterator be ? Call(syncMethod, obj).
+        iii. Return ? CreateAsyncFromSyncIterator(syncIterator).
+    ...
+
+    %AsyncFromSyncIteratorPrototype%.next ( value )
+
+    ...
+    5. Let nextResult be IteratorNext(syncIterator, value).
+    ...
+    7. Let nextValue be IteratorValue(nextResult).
+    ...
+    9. Let nextDone be IteratorComplete(nextResult).
+    ...
+    12. Perform ! Call(valueWrapperCapability.[[Resolve]], undefined,
+        « nextValue »).
+    ...
+    14. Set onFulfilled.[[Done]] to nextDone.
+    15. Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]],
+        onFulfilled, undefined, promiseCapability).
+    ...
+
+    Async Iterator Value Unwrap Functions
+
+    1. Return ! CreateIterResultObject(value, F.[[Done]]).
+
+---*/
+var log = [];
+var obj = {
+  get [Symbol.iterator]() {
+    log.push({
+      name: "get [Symbol.iterator]",
+      thisValue: this
+    });
+    return function() {
+      log.push({
+        name: "call [Symbol.iterator]",
+        thisValue: this,
+        args: [...arguments]
+      });
+      var nextCount = 0;
+      return {
+        name: "syncIterator",
+        get next() {
+          log.push({
+            name: "get next",
+            thisValue: this
+          });
+          return function() {
+            log.push({
+              name: "call next",
+              thisValue: this,
+              args: [...arguments]
+            });
+
+            nextCount++;
+            if (nextCount == 1) {
+              return {
+                name: "next-result-1",
+                get value() {
+                  log.push({
+                    name: "get next value (1)",
+                    thisValue: this
+                  });
+                  return "next-value-1";
+                },
+                get done() {
+                  log.push({
+                    name: "get next done (1)",
+                    thisValue: this
+                  });
+                  return false;
+                }
+              };
+            }
+
+            return {
+              name: "next-result-2",
+              get value() {
+                log.push({
+                  name: "get next value (2)",
+                  thisValue: this
+                });
+                return "next-value-2";
+              },
+              get done() {
+                log.push({
+                  name: "get next done (2)",
+                  thisValue: this
+                });
+                return true;
+              }
+            };
+          };
+        }
+      };
+    };
+  },
+  get [Symbol.asyncIterator]() {
+    log.push({ name: "get [Symbol.asyncIterator]" });
+    return null;
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    var v = yield* obj;
+    log.push({
+      name: "after yield*",
+      value: v
+    });
+    return "return-value";
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next("next-arg-1").then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get [Symbol.asyncIterator]");
+
+  assert.sameValue(log[2].name, "get [Symbol.iterator]");
+  assert.sameValue(log[2].thisValue, obj, "get [Symbol.iterator] thisValue");
+
+  assert.sameValue(log[3].name, "call [Symbol.iterator]");
+  assert.sameValue(log[3].thisValue, obj, "[Symbol.iterator] thisValue");
+  assert.sameValue(log[3].args.length, 0, "[Symbol.iterator] args.length");
+
+  assert.sameValue(log[4].name, "get next");
+  assert.sameValue(log[4].thisValue.name, "syncIterator", "get next thisValue");
+
+  assert.sameValue(log[5].name, "call next");
+  assert.sameValue(log[5].thisValue.name, "syncIterator", "next thisValue");
+  assert.sameValue(log[5].args.length, 1, "next args.length");
+  assert.sameValue(log[5].args[0], undefined, "next args[0]");
+
+  assert.sameValue(log[6].name, "get next done (1)");
+  assert.sameValue(log[6].thisValue.name, "next-result-1", "get next done thisValue");
+
+  assert.sameValue(log[7].name, "get next value (1)");
+  assert.sameValue(log[7].thisValue.name, "next-result-1", "get next value thisValue");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 8, "log.length");
+
+  iter.next("next-arg-2").then(v => {
+    assert.sameValue(log[8].name, "call next");
+    assert.sameValue(log[8].thisValue.name, "syncIterator", "next thisValue");
+    assert.sameValue(log[8].args.length, 1, "next args.length");
+    assert.sameValue(log[8].args[0], "next-arg-2", "next args[0]");
+
+    assert.sameValue(log[9].name, "get next done (2)");
+    assert.sameValue(log[9].thisValue.name, "next-result-2", "get next done thisValue");
+
+    assert.sameValue(log[10].name, "get next value (2)");
+    assert.sameValue(log[10].thisValue.name, "next-result-2", "get next value thisValue");
+
+    assert.sameValue(log[11].name, "after yield*");
+    assert.sameValue(log[11].value, "next-value-2");
+
+    assert.sameValue(v.value, "return-value");
+    assert.sameValue(v.done, true);
+
+    assert.sameValue(log.length, 12, "log.length");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-sync-return.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-sync-return.js
new file mode 100644
index 0000000000..d516923f24
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-sync-return.js
@@ -0,0 +1,197 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-sync-return.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: execution order for yield* with sync iterator and return() (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      c. Else,
+        i. Assert: received.[[Type]] is return.
+        ii. Let return be ? GetMethod(iterator, "return").
+        iii. If return is undefined, return Completion(received).
+        iv. Let innerReturnResult be ? Call(return, iterator,
+            « received.[[Value]] »).
+        v. If generatorKind is async, then set innerReturnResult to
+           ? Await(innerReturnResult).
+        ...
+        vii. Let done be ? IteratorComplete(innerReturnResult).
+        viii. If done is true, then
+             1. Let value be ? IteratorValue(innerReturnResult).
+             2. Return Completion{[[Type]]: return, [[Value]]: value,
+                [[Target]]: empty}.
+        ix. Let received be GeneratorYield(innerResult).
+
+    %AsyncFromSyncIteratorPrototype%.return ( value )
+
+    5. Let return be GetMethod(syncIterator, "return").
+    ...
+    ...
+    8. Let returnResult be Call(return, syncIterator, « value »).
+    ...
+    11. Let returnValue be IteratorValue(returnResult).
+    ..
+    13. Let returnDone be IteratorComplete(returnResult).
+    ...
+    16. Perform ! Call(valueWrapperCapability.[[Resolve]], undefined, « returnValue »).
+    ...
+    18. Set onFulfilled.[[Done]] to returnDone.
+    19. Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]],
+        onFulfilled, undefined, promiseCapability).
+    ...
+
+---*/
+var log = [];
+var obj = {
+  [Symbol.iterator]() {
+    var returnCount = 0;
+    return {
+      name: "syncIterator",
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get return() {
+        log.push({
+          name: "get return",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call return",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          returnCount++;
+          if (returnCount == 1) {
+            return {
+              name: "return-result-1",
+              get value() {
+                log.push({
+                  name: "get return value (1)",
+                  thisValue: this
+                });
+                return "return-value-1";
+              },
+              get done() {
+                log.push({
+                  name: "get return done (1)",
+                  thisValue: this
+                });
+                return false;
+              }
+            };
+          }
+
+          return {
+            name: "return-result-2",
+            get value() {
+              log.push({
+                name: "get return value (2)",
+                thisValue: this
+              });
+              return "return-value-2";
+            },
+            get done() {
+              log.push({
+                name: "get return done (2)",
+                thisValue: this
+              });
+              return true;
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    yield* obj;
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.return("return-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get return");
+    assert.sameValue(log[2].thisValue.name, "syncIterator", "get return thisValue");
+
+    assert.sameValue(log[3].name, "call return");
+    assert.sameValue(log[3].thisValue.name, "syncIterator", "return thisValue");
+    assert.sameValue(log[3].args.length, 1, "return args.length");
+    assert.sameValue(log[3].args[0], "return-arg-1", "return args[0]");
+
+    assert.sameValue(log[4].name, "get return done (1)");
+    assert.sameValue(log[4].thisValue.name, "return-result-1", "get return done thisValue");
+
+    assert.sameValue(log[5].name, "get return value (1)");
+    assert.sameValue(log[5].thisValue.name, "return-result-1", "get return value thisValue");
+
+    assert.sameValue(v.value, "return-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 6, "log.length");
+
+    iter.return().then(v => {
+      assert.sameValue(log[6].name, "get return");
+      assert.sameValue(log[6].thisValue.name, "syncIterator", "get return thisValue");
+
+      assert.sameValue(log[7].name, "call return");
+      assert.sameValue(log[7].thisValue.name, "syncIterator", "get return thisValue");
+      assert.sameValue(log[7].args.length, 1, "return args.length");
+      assert.sameValue(log[7].args[0], undefined, "return args[0]");
+
+      assert.sameValue(log[8].name, "get return done (2)");
+      assert.sameValue(log[8].thisValue.name, "return-result-2", "get return done thisValue");
+
+      assert.sameValue(log[9].name, "get return value (2)");
+      assert.sameValue(log[9].thisValue.name, "return-result-2", "get return value thisValue");
+
+      assert.sameValue(v.value, "return-value-2");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 10, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-star-sync-throw.js b/js/src/tests/test262/language/expressions/async-generator/yield-star-sync-throw.js
new file mode 100644
index 0000000000..b84a1ebd79
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-star-sync-throw.js
@@ -0,0 +1,203 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-sync-throw.case
+// - src/async-generators/default/async-expression.template
+/*---
+description: execution order for yield* with sync iterator and throw() (Unnamed async generator expression)
+esid: prod-AsyncGeneratorExpression
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorExpression :
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    ...
+    6. Repeat
+      ...
+      b. Else if received.[[Type]] is throw, then
+        i. Let throw be ? GetMethod(iterator, "throw").
+        ii. If throw is not undefined, then
+          1. Let innerResult be ? Call(throw, iterator, « received.[[Value]] »).
+          2. If generatorKind is async, then set innerResult to
+             ? Await(innerResult).
+          ...
+          5. Let done be ? IteratorComplete(innerResult).
+          6. If done is true, then
+            a. Return ? IteratorValue(innerResult).
+          7. Let received be GeneratorYield(innerResult).
+      ...
+
+    %AsyncFromSyncIteratorPrototype%.throw ( value )
+
+    ...
+    5. Let throw be GetMethod(syncIterator, "throw").
+    ...
+    8. Let throwResult be Call(throw, syncIterator, « value »).
+    ...
+    11. Let throwValue be IteratorValue(throwResult).
+    ...
+    13. Let throwDone be IteratorComplete(throwResult).
+    ...
+    16. Perform ! Call(valueWrapperCapability.[[Resolve]], undefined,
+        « throwValue »).
+    ...
+    18. Set onFulfilled.[[Done]] to throwDone.
+    19. Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]],
+        onFulfilled, undefined, promiseCapability).
+    ...
+
+---*/
+var log = [];
+var obj = {
+  [Symbol.iterator]() {
+    var throwCount = 0;
+    return {
+      name: "syncIterator",
+      get next() {
+        log.push({ name: "get next" });
+        return function() {
+          return {
+            value: "next-value-1",
+            done: false
+          };
+        };
+      },
+      get throw() {
+        log.push({
+          name: "get throw",
+          thisValue: this
+        });
+        return function() {
+          log.push({
+            name: "call throw",
+            thisValue: this,
+            args: [...arguments]
+          });
+
+          throwCount++;
+          if (throwCount == 1) {
+            return {
+              name: "throw-result-1",
+              get value() {
+                log.push({
+                  name: "get throw value (1)",
+                  thisValue: this
+                });
+                return "throw-value-1";
+              },
+              get done() {
+                log.push({
+                  name: "get throw done (1)",
+                  thisValue: this
+                });
+                return false;
+              }
+            };
+          }
+
+          return {
+            name: "throw-result-2",
+            get value() {
+              log.push({
+                name: "get throw value (2)",
+                thisValue: this
+              });
+              return "throw-value-2";
+            },
+            get done() {
+              log.push({
+                name: "get throw done (2)",
+                thisValue: this
+              });
+              return true;
+            }
+          };
+        };
+      }
+    };
+  }
+};
+
+
+
+var callCount = 0;
+
+var gen = async function *() {
+  callCount += 1;
+  log.push({ name: "before yield*" });
+    var v = yield* obj;
+    log.push({
+      name: "after yield*",
+      value: v
+    });
+    return "return-value";
+
+};
+
+var iter = gen();
+
+assert.sameValue(log.length, 0, "log.length");
+
+iter.next().then(v => {
+  assert.sameValue(log[0].name, "before yield*");
+
+  assert.sameValue(log[1].name, "get next");
+
+  assert.sameValue(v.value, "next-value-1");
+  assert.sameValue(v.done, false);
+
+  assert.sameValue(log.length, 2, "log.length");
+
+  iter.throw("throw-arg-1").then(v => {
+    assert.sameValue(log[2].name, "get throw");
+    assert.sameValue(log[2].thisValue.name, "syncIterator", "get throw thisValue");
+
+    assert.sameValue(log[3].name, "call throw");
+    assert.sameValue(log[3].thisValue.name, "syncIterator", "throw thisValue");
+    assert.sameValue(log[3].args.length, 1, "throw args.length");
+    assert.sameValue(log[3].args[0], "throw-arg-1", "throw args[0]");
+
+    assert.sameValue(log[4].name, "get throw done (1)");
+    assert.sameValue(log[4].thisValue.name, "throw-result-1", "get throw done thisValue");
+
+    assert.sameValue(log[5].name, "get throw value (1)");
+    assert.sameValue(log[5].thisValue.name, "throw-result-1", "get throw value thisValue");
+
+    assert.sameValue(v.value, "throw-value-1");
+    assert.sameValue(v.done, false);
+
+    assert.sameValue(log.length, 6, "log.length");
+
+    iter.throw().then(v => {
+      assert.sameValue(log[6].name, "get throw");
+      assert.sameValue(log[6].thisValue.name, "syncIterator", "get throw thisValue");
+
+      assert.sameValue(log[7].name, "call throw");
+      assert.sameValue(log[7].thisValue.name, "syncIterator", "throw thisValue");
+      assert.sameValue(log[7].args.length, 1, "throw args.length");
+      assert.sameValue(log[7].args[0], undefined, "throw args[0]");
+
+      assert.sameValue(log[8].name, "get throw done (2)");
+      assert.sameValue(log[8].thisValue.name, "throw-result-2", "get throw done thisValue");
+
+      assert.sameValue(log[9].name, "get throw value (2)");
+      assert.sameValue(log[9].thisValue.name, "throw-result-2", "get throw value thisValue");
+
+      assert.sameValue(log[10].name, "after yield*");
+      assert.sameValue(log[10].value, "throw-value-2");
+
+      assert.sameValue(v.value, "return-value");
+      assert.sameValue(v.done, true);
+
+      assert.sameValue(log.length, 11, "log.length");
+    }).then($DONE, $DONE);
+  }).catch($DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-thenable-create-resolving-functions-reject.js b/js/src/tests/test262/language/expressions/async-generator/yield-thenable-create-resolving-functions-reject.js
new file mode 100644
index 0000000000..1acb66a6f3
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-thenable-create-resolving-functions-reject.js
@@ -0,0 +1,75 @@
+// |reftest| async
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-generator-function-definitions-runtime-semantics-evaluation
+description: >
+  `reject` is anonymous built-in function with length of 1.
+info: |
+  YieldExpression : yield AssignmentExpression 
+
+  [...]
+  4. If generatorKind is async, then return ? AsyncGeneratorYield(value).
+
+  AsyncGeneratorYield ( value )
+
+  [...]
+  5. Set value to ? Await(value).
+  [...]
+  9. Return ! AsyncGeneratorResolve(generator, value, false).
+
+  Await
+
+  [...]
+  2. Let promise be ? PromiseResolve(%Promise%, value).
+  [...]
+
+  PromiseResolve ( C, x )
+
+  [...]
+  3. Let promiseCapability be ? NewPromiseCapability(C).
+  4. Perform ? Call(promiseCapability.[[Resolve]], undefined, « x »).
+  5. Return promiseCapability.[[Promise]].
+
+  NewPromiseCapability ( C )
+
+  [...]
+  7. Let promise be ? Construct(C, « executor »).
+  [...]
+  11. Return promiseCapability.
+
+  Promise ( executor )
+
+  [...]
+  8. Let resolvingFunctions be CreateResolvingFunctions(promise).
+  [...]
+  11. Return promise.
+
+  CreateResolvingFunctions ( promise )
+
+  [...]
+  7. Let reject be ! CreateBuiltinFunction(stepsReject, « [[Promise]], [[AlreadyResolved]] »).
+  [...]
+  10. Return the Record { [[Resolve]]: resolve, [[Reject]]: reject }.
+flags: [async]
+features: [async-iteration, Reflect.construct]
+includes: [isConstructor.js]
+---*/
+
+var thenable = {
+  then: function(resolve, reject) {
+    resolve(reject);
+  },
+};
+
+var iter = (async function*() {
+  yield thenable;
+}());
+
+iter.next().then(function(result) {
+  var reject = result.value;
+  assert(!isConstructor(reject));
+  assert.sameValue(reject.length, 1);
+  assert.sameValue(reject.name, '');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/expressions/async-generator/yield-thenable-create-resolving-functions-resolve.js b/js/src/tests/test262/language/expressions/async-generator/yield-thenable-create-resolving-functions-resolve.js
new file mode 100644
index 0000000000..543b17c9f9
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/async-generator/yield-thenable-create-resolving-functions-resolve.js
@@ -0,0 +1,75 @@
+// |reftest| async
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-generator-function-definitions-runtime-semantics-evaluation
+description: >
+  `resolve` is anonymous built-in function with length of 1.
+info: |
+  YieldExpression : yield AssignmentExpression 
+
+  [...]
+  4. If generatorKind is async, then return ? AsyncGeneratorYield(value).
+
+  AsyncGeneratorYield ( value )
+
+  [...]
+  5. Set value to ? Await(value).
+  [...]
+  9. Return ! AsyncGeneratorResolve(generator, value, false).
+
+  Await
+
+  [...]
+  2. Let promise be ? PromiseResolve(%Promise%, value).
+  [...]
+
+  PromiseResolve ( C, x )
+
+  [...]
+  3. Let promiseCapability be ? NewPromiseCapability(C).
+  4. Perform ? Call(promiseCapability.[[Resolve]], undefined, « x »).
+  5. Return promiseCapability.[[Promise]].
+
+  NewPromiseCapability ( C )
+
+  [...]
+  7. Let promise be ? Construct(C, « executor »).
+  [...]
+  11. Return promiseCapability.
+
+  Promise ( executor )
+
+  [...]
+  8. Let resolvingFunctions be CreateResolvingFunctions(promise).
+  [...]
+  11. Return promise.
+
+  CreateResolvingFunctions ( promise )
+
+  [...]
+  3. Let resolve be ! CreateBuiltinFunction(stepsResolve, « [[Promise]], [[AlreadyResolved]] »).
+  [...]
+  10. Return the Record { [[Resolve]]: resolve, [[Reject]]: reject }.
+flags: [async]
+features: [async-iteration, Reflect.construct]
+includes: [isConstructor.js]
+---*/
+
+var thenable = {
+  then: function(resolve) {
+    resolve(resolve);
+  },
+};
+
+var iter = (async function*() {
+  yield thenable;
+}());
+
+iter.next().then(function(result) {
+  var resolve = result.value;
+  assert(!isConstructor(resolve));
+  assert.sameValue(resolve.length, 1);
+  assert.sameValue(resolve.name, '');
+}).then($DONE, $DONE);