Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

311 files changed, 16337 insertions, 0 deletions

diff --git a/js/src/tests/test262/language/statements/async-generator/array-destructuring-param-strict-body.js b/js/src/tests/test262/language/statements/async-generator/array-destructuring-param-strict-body.js
new file mode 100644
index 0000000000..4660b77b66
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl.template
+/*---
+description: ArrayBindingPattern and Use Strict Directive are not allowed to coexist for the same function. (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [rest-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+
+---*/
+$DONOTEVALUATE();
+
+
+async function* f([element]) {
+  "use strict";
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/await-as-binding-identifier-escaped.js b/js/src/tests/test262/language/statements/async-generator/await-as-binding-identifier-escaped.js
new file mode 100644
index 0000000000..a16ff93677
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/await-as-binding-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-binding-identifier-escaped.case
+// - src/async-generators/syntax/async-declaration.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+async function *gen() {
+  var \u0061wait;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/await-as-binding-identifier.js b/js/src/tests/test262/language/statements/async-generator/await-as-binding-identifier.js
new file mode 100644
index 0000000000..7542c47b57
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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".
+
+---*/
+$DONOTEVALUATE();
+
+
+async function *gen() {
+  var await;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/await-as-identifier-reference-escaped.js b/js/src/tests/test262/language/statements/async-generator/await-as-identifier-reference-escaped.js
new file mode 100644
index 0000000000..51e5721c93
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/await-as-identifier-reference-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-identifier-reference-escaped.case
+// - src/async-generators/syntax/async-declaration.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+async function *gen() {
+  void \u0061wait;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/await-as-identifier-reference.js b/js/src/tests/test262/language/statements/async-generator/await-as-identifier-reference.js
new file mode 100644
index 0000000000..8a6a5d34df
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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".
+
+---*/
+$DONOTEVALUATE();
+
+
+async function *gen() {
+  void await;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/await-as-label-identifier-escaped.js b/js/src/tests/test262/language/statements/async-generator/await-as-label-identifier-escaped.js
new file mode 100644
index 0000000000..b84fe46ab9
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/await-as-label-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/await-as-label-identifier-escaped.case
+// - src/async-generators/syntax/async-declaration.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a label identifier. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Await] parameter and
+    StringValue of Identifier is "await".
+
+---*/
+$DONOTEVALUATE();
+
+
+async function *gen() {
+  \u0061wait: ;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/await-as-label-identifier.js b/js/src/tests/test262/language/statements/async-generator/await-as-label-identifier.js
new file mode 100644
index 0000000000..bf5216ae72
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: await is a reserved keyword within generator function bodies and may not be used as a label identifier. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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();
+
+
+async function *gen() {
+  await: ;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/browser.js b/js/src/tests/test262/language/statements/async-generator/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/browser.js
diff --git a/js/src/tests/test262/language/statements/async-generator/dflt-params-abrupt.js b/js/src/tests/test262/language/statements/async-generator/dflt-params-abrupt.js
new file mode 100644
index 0000000000..e22664b6d2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl.template
+/*---
+description: Abrupt completion returned by evaluation of initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [default-parameters, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f(_ = (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/statements/async-generator/dflt-params-arg-val-not-undefined.js b/js/src/tests/test262/language/statements/async-generator/dflt-params-arg-val-not-undefined.js
new file mode 100644
index 0000000000..dee107ae7e
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dflt-params-arg-val-not-undefined.js
@@ -0,0 +1,65 @@
+// |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-decl.template
+/*---
+description: Use of initializer when argument value is not `undefined` (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [default-parameters, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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
+async function* ref(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/statements/async-generator/dflt-params-arg-val-undefined.js b/js/src/tests/test262/language/statements/async-generator/dflt-params-arg-val-undefined.js
new file mode 100644
index 0000000000..614a523460
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dflt-params-arg-val-undefined.js
@@ -0,0 +1,48 @@
+// |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-decl.template
+/*---
+description: Use of initializer when argument value is `undefined` (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [default-parameters, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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
+async function* ref(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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dflt-params-duplicates.js b/js/src/tests/test262/language/statements/async-generator/dflt-params-duplicates.js
new file mode 100644
index 0000000000..48ac553082
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dflt-params-duplicates.js
@@ -0,0 +1,42 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-duplicates.case
+// - src/function-forms/syntax/async-gen-func-decl.template
+/*---
+description: It is a Syntax Error if BoundNames of FormalParameters contains any duplicate elements. (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [default-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    14.1.2 Static Semantics: Early Errors
+
+    StrictFormalParameters : FormalParameters
+
+    - It is a Syntax Error if BoundNames of FormalParameters contains any
+      duplicate elements.
+
+    FormalParameters : FormalParameterList
+
+    - It is a Syntax Error if IsSimpleParameterList of FormalParameterList is
+      false and BoundNames of FormalParameterList contains any duplicate
+      elements.
+
+---*/
+$DONOTEVALUATE();
+
+
+async function* f(x = 0, x) {
+  
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/dflt-params-ref-later.js b/js/src/tests/test262/language/statements/async-generator/dflt-params-ref-later.js
new file mode 100644
index 0000000000..e17f8f5136
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl.template
+/*---
+description: Referencing a parameter that occurs later in the ParameterList (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [default-parameters, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f(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/statements/async-generator/dflt-params-ref-prior.js b/js/src/tests/test262/language/statements/async-generator/dflt-params-ref-prior.js
new file mode 100644
index 0000000000..2df4cd9872
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dflt-params-ref-prior.js
@@ -0,0 +1,45 @@
+// |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-decl.template
+/*---
+description: Referencing a parameter that occurs earlier in the ParameterList (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [default-parameters, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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
+async function* ref(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/statements/async-generator/dflt-params-ref-self.js b/js/src/tests/test262/language/statements/async-generator/dflt-params-ref-self.js
new file mode 100644
index 0000000000..24b4278be1
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl.template
+/*---
+description: Referencing a parameter from within its own initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [default-parameters, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f(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/statements/async-generator/dflt-params-rest.js b/js/src/tests/test262/language/statements/async-generator/dflt-params-rest.js
new file mode 100644
index 0000000000..50094b3de8
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl.template
+/*---
+description: RestParameter does not support an initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [default-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+
+
+async function* f(...x = []) {
+  
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/dflt-params-trailing-comma.js b/js/src/tests/test262/language/statements/async-generator/dflt-params-trailing-comma.js
new file mode 100644
index 0000000000..f5e049aeda
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dflt-params-trailing-comma.js
@@ -0,0 +1,40 @@
+// |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-decl.template
+/*---
+description: A trailing comma should not increase the respective length, using default parameters (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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
+async function* ref(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, $DONE);
+
+assert.sameValue(ref.length, 1, 'length is properly set');
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-init-iter-close.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-init-iter-close.js
new file mode 100644
index 0000000000..66717ee508
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-init-iter-close.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-close.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Iterator is closed when not exhausted by pattern evaluation (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: false };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+async function* f([x]) {
+  assert.sameValue(doneCallCount, 1);
+  callCount = callCount + 1;
+};
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-init-iter-get-err-array-prototype.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-init-iter-get-err-array-prototype.js
new file mode 100644
index 0000000000..1a9865bda0
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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];
+
+
+async function* f([x, y, z]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([1, 2, 3]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-init-iter-get-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-init-iter-get-err.js
new file mode 100644
index 0000000000..47760857b7
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+};
+
+
+async function* f([x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-init-iter-no-close.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-init-iter-no-close.js
new file mode 100644
index 0000000000..f42a6ef574
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-init-iter-no-close.js
@@ -0,0 +1,52 @@
+// |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-decl.template
+/*---
+description: Iterator is not closed when exhausted by pattern evaluation (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/ary-name-iter-val.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-name-iter-val.js
new file mode 100644
index 0000000000..9dd28b5cbd
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-name-iter-val.js
@@ -0,0 +1,51 @@
+// |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-decl.template
+/*---
+description: SingleNameBinding with normal value iteration (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elem-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elem-init.js
new file mode 100644
index 0000000000..5eeaddad31
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elem-init.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-init.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+async function* f([[x, y, z] = [4, 5, 6]]) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+  callCount = callCount + 1;
+};
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elem-iter.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elem-iter.js
new file mode 100644
index 0000000000..cbbc764a7b
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elem-iter.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-iter.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+async function* f([[x, y, z] = [4, 5, 6]]) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, 8);
+  assert.sameValue(z, 9);
+  callCount = callCount + 1;
+};
+f([[7, 8, 9]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elision-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elision-init.js
new file mode 100644
index 0000000000..723e86f68d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elision-init.js
@@ -0,0 +1,50 @@
+// |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-decl.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([[,] = g()]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elision-iter.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elision-iter.js
new file mode 100644
index 0000000000..40495d162f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-elision-iter.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-iter.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var callCount = 0;
+function* g() {
+  callCount += 1;
+};
+
+
+var callCount = 0;
+async function* f([[,] = g()]) {
+  assert.sameValue(callCount, 0);
+  callCount = callCount + 1;
+};
+f([[]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-empty-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-empty-init.js
new file mode 100644
index 0000000000..fbdc137fd1
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-empty-init.js
@@ -0,0 +1,46 @@
+// |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-decl.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([[] = 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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-empty-iter.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-empty-iter.js
new file mode 100644
index 0000000000..51d5ea22a1
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-empty-iter.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-iter.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var initCount = 0;
+
+
+var callCount = 0;
+async function* f([[] = function() { initCount += 1; }()]) {
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+f([[23]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-rest-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-rest-init.js
new file mode 100644
index 0000000000..78f1782d92
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-rest-init.js
@@ -0,0 +1,47 @@
+// |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-decl.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([[...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/statements/async-generator/dstr/ary-ptrn-elem-ary-rest-iter.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-rest-iter.js
new file mode 100644
index 0000000000..9271decb43
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-rest-iter.js
@@ -0,0 +1,50 @@
+// |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-decl.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([[...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/statements/async-generator/dstr/ary-ptrn-elem-ary-val-null.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-ary-val-null.js
new file mode 100644
index 0000000000..d0ebed22f0
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Nested array destructuring with a null value (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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).
+---*/
+
+
+async function* f([[x]]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([null]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-exhausted.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-exhausted.js
new file mode 100644
index 0000000000..aaf0cfd4cd
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-exhausted.js
@@ -0,0 +1,42 @@
+// |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-decl.template
+/*---
+description: Destructuring initializer with an exhausted iterator (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([x = 23]) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-arrow.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..41133d343f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-arrow.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: SingleNameBinding does assign name to arrow functions (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+async function* f([arrow = () => {}]) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-class.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-class.js
new file mode 100644
index 0000000000..361a54ca1e
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-class.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-class.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-cover.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..35ac762a96
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-cover.js
@@ -0,0 +1,44 @@
+// |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-decl.template
+/*---
+description: SingleNameBinding does assign name to "anonymous" functions "through" cover grammar (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-fn.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..0553c068fe
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-fn.js
@@ -0,0 +1,44 @@
+// |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-decl.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-gen.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..c785c7d025
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-fn-name-gen.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-gen.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-hole.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-hole.js
new file mode 100644
index 0000000000..2e66084421
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-hole.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-hole.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Destructuring initializer with a "hole" (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    SingleNameBinding : BindingIdentifier Initializeropt
+    [...] 6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v). 8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+async function* f([x = 23]) {
+  assert.sameValue(x, 23);
+  // another statement
+  callCount = callCount + 1;
+};
+f([,]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-skipped.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-skipped.js
new file mode 100644
index 0000000000..937670ce09
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-skipped.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+async function* f([w = counter(), x = counter(), y = counter(), z = counter()]) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+f([null, 0, false, '']).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-throws.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-throws.js
new file mode 100644
index 0000000000..a47cab8a60
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Destructuring initializer returns an abrupt completion (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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).
+---*/
+
+
+async function* f([x = (function() { throw new Test262Error(); })()]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f([undefined]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-undef.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-undef.js
new file mode 100644
index 0000000000..711fcfc10b
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-undef.js
@@ -0,0 +1,41 @@
+// |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-decl.template
+/*---
+description: Destructuring initializer with an undefined value (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/ary-ptrn-elem-id-init-unresolvable.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-init-unresolvable.js
new file mode 100644
index 0000000000..91a4c062fe
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f([ x = unresolvableReference ]) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f([]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-complete.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-complete.js
new file mode 100644
index 0000000000..d1a11c6fac
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-complete.js
@@ -0,0 +1,45 @@
+// |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-decl.template
+/*---
+description: SingleNameBinding when value iteration completes (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([x]) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-done.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-done.js
new file mode 100644
index 0000000000..d4b4d4e018
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-done.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-done.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+async function* f([_, x]) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-step-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-step-err.js
new file mode 100644
index 0000000000..f572a96d70
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+    }
+  };
+};
+
+
+async function* f([x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(g);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-val-array-prototype.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-val-array-prototype.js
new file mode 100644
index 0000000000..38b3441861
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-val-array-prototype.js
@@ -0,0 +1,61 @@
+// |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-decl.template
+/*---
+description: Array destructuring uses overriden Array.prototype[Symbol.iterator] (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/ary-ptrn-elem-id-iter-val-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-val-err.js
new file mode 100644
index 0000000000..178441885a
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+    }
+  };
+};
+
+
+async function* f([x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(g);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-val.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-val.js
new file mode 100644
index 0000000000..5c49770c68
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-id-iter-val.js
@@ -0,0 +1,51 @@
+// |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-decl.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-id-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-id-init.js
new file mode 100644
index 0000000000..050ac6608e
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-id-init.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id-init.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+async function* f([{ x, y, z } = { x: 44, y: 55, z: 66 }]) {
+  assert.sameValue(x, 44);
+  assert.sameValue(y, 55);
+  assert.sameValue(z, 66);
+  callCount = callCount + 1;
+};
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-id.js
new file mode 100644
index 0000000000..5b956e129f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-id.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+async function* f([{ x, y, z } = { x: 44, y: 55, z: 66 }]) {
+  assert.sameValue(x, 11);
+  assert.sameValue(y, 22);
+  assert.sameValue(z, 33);
+  callCount = callCount + 1;
+};
+f([{ x: 11, y: 22, z: 33 }]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-prop-id-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-prop-id-init.js
new file mode 100644
index 0000000000..1880fe720f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-prop-id-init.js
@@ -0,0 +1,53 @@
+// |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-decl.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([{ 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/statements/async-generator/dstr/ary-ptrn-elem-obj-prop-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-prop-id.js
new file mode 100644
index 0000000000..46e8755d07
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-prop-id.js
@@ -0,0 +1,53 @@
+// |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-decl.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([{ 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/statements/async-generator/dstr/ary-ptrn-elem-obj-val-null.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-val-null.js
new file mode 100644
index 0000000000..a70d7d5795
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Nested object destructuring with a null value (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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).
+---*/
+
+
+async function* f([{ x }]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([null]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-val-undef.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elem-obj-val-undef.js
new file mode 100644
index 0000000000..025274a7d6
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Nested object destructuring with a value of `undefined` (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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).
+---*/
+
+
+async function* f([{ x }]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f([]);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elision-exhausted.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elision-exhausted.js
new file mode 100644
index 0000000000..b7f11d1ab4
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elision-exhausted.js
@@ -0,0 +1,48 @@
+// |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-decl.template
+/*---
+description: Elision accepts exhausted iterator (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([,]) {
+  
+  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/statements/async-generator/dstr/ary-ptrn-elision-step-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elision-step-err.js
new file mode 100644
index 0000000000..cf759e2f6f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Elision advances iterator and forwards abrupt completions (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+}();
+
+
+async function* f([,]) {
+  
+};
+
+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/statements/async-generator/dstr/ary-ptrn-elision.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elision.js
new file mode 100644
index 0000000000..2571145e47
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-elision.js
@@ -0,0 +1,57 @@
+// |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-decl.template
+/*---
+description: Elision advances iterator (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([,]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+f(g()).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-empty.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-empty.js
new file mode 100644
index 0000000000..db417ba5bf
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-empty.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: No iteration occurs for an "empty" array binding pattern (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+async function* f([]) {
+  assert.sameValue(iterations, 0);
+  callCount = callCount + 1;
+};
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-ary-elem.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-ary-elem.js
new file mode 100644
index 0000000000..1d1e9fd881
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-ary-elem.js
@@ -0,0 +1,64 @@
+// |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-decl.template
+/*---
+description: Rest element containing an array BindingElementList pattern (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([...[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/statements/async-generator/dstr/ary-ptrn-rest-ary-elision.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-ary-elision.js
new file mode 100644
index 0000000000..e83247fdc5
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-ary-elision.js
@@ -0,0 +1,70 @@
+// |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-decl.template
+/*---
+description: Rest element containing an elision (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([...[,]]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 1);
+  callCount = callCount + 1;
+};
+f(g()).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-ary-empty.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-ary-empty.js
new file mode 100644
index 0000000000..73693bd1bd
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-ary-empty.js
@@ -0,0 +1,53 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-empty.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Rest element containing an "empty" array pattern (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+async function* f([...[]]) {
+  assert.sameValue(iterations, 1);
+  callCount = callCount + 1;
+};
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-ary-rest.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-ary-rest.js
new file mode 100644
index 0000000000..d1a09db82f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-ary-rest.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-rest.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Rest element containing a rest element (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+async function* f([...[...x]]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+
+  callCount = callCount + 1;
+};
+f(values).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-direct.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-direct.js
new file mode 100644
index 0000000000..e12f4ca909
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-direct.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-direct.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Lone rest element (direct binding) (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+includes: [compareArray.js]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingIdentifier
+
+    [...]
+    2. Let A be ! ArrayCreate(0).
+    3. Let n be 0.
+    4. Repeat,
+        [...]
+        f. Perform ! CreateDataPropertyOrThrow(A, ! ToString(n), nextValue).
+        g. Set n to n + 1.
+
+---*/
+
+
+var callCount = 0;
+async function* f([...x]) {
+  assert(Array.isArray(x));
+  assert.compareArray(x, [1]);
+  callCount = callCount + 1;
+};
+f([1]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-elision-next-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-elision-next-err.js
new file mode 100644
index 0000000000..17aef78e13
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Rest element following elision elements (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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(); })();
+
+
+async function* f([, ...x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-elision.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-elision.js
new file mode 100644
index 0000000000..e78db95d58
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-elision.js
@@ -0,0 +1,45 @@
+// |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-decl.template
+/*---
+description: Rest element following elision elements (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([ , , ...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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-exhausted.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-exhausted.js
new file mode 100644
index 0000000000..afbae9f5b7
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-exhausted.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-exhausted.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: RestElement applied to an exhausted iterator (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. If environment is undefined, return PutValue(lhs, A).
+          ii. Return InitializeReferencedBinding(lhs, A).
+
+---*/
+
+
+var callCount = 0;
+async function* f([, , ...x]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 0);
+  callCount = callCount + 1;
+};
+f([1, 2]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-iter-step-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-iter-step-err.js
new file mode 100644
index 0000000000..c8ea051d59
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+}();
+
+
+async function* f([...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/statements/async-generator/dstr/ary-ptrn-rest-id-iter-val-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id-iter-val-err.js
new file mode 100644
index 0000000000..58b4e41cae
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+    }
+  };
+};
+
+
+async function* f([...x]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(iter);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id.js
new file mode 100644
index 0000000000..c6841c4a97
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-id.js
@@ -0,0 +1,42 @@
+// |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-decl.template
+/*---
+description: Lone rest element (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([...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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-init-ary.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-init-ary.js
new file mode 100644
index 0000000000..bb9b3db04e
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-init-ary.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-ary.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Rest element (nested array pattern) does not support initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...[ x ] = []]) {
+  
+  callCount = callCount + 1;
+};
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-init-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-init-id.js
new file mode 100644
index 0000000000..ff6045f1af
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-init-id.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-id.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Rest element (identifier) does not support initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...x = []]) {
+  
+  callCount = callCount + 1;
+};
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-init-obj.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-init-obj.js
new file mode 100644
index 0000000000..613a299c64
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-init-obj.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-obj.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Rest element (nested object pattern) does not support initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...{ x } = []]) {
+  
+  callCount = callCount + 1;
+};
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-not-final-ary.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-not-final-ary.js
new file mode 100644
index 0000000000..5f7c9ee7e0
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-not-final-ary.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-ary.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Rest element (array binding pattern) may not be followed by any element (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...[x], y]) {
+  
+  callCount = callCount + 1;
+};
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-not-final-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-not-final-id.js
new file mode 100644
index 0000000000..e05edefa89
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-not-final-id.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-id.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Rest element (identifier) may not be followed by any element (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...x, y]) {
+  
+  callCount = callCount + 1;
+};
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-not-final-obj.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-not-final-obj.js
new file mode 100644
index 0000000000..33c334013c
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-not-final-obj.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-obj.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Rest element (object binding pattern) may not be followed by any element (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...{ x }, y]) {
+  
+  callCount = callCount + 1;
+};
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-obj-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-obj-id.js
new file mode 100644
index 0000000000..29a9d3265b
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-obj-id.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-id.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Rest element containing an object binding pattern (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+
+
+var callCount = 0;
+async function* f([...{ length }]) {
+  assert.sameValue(length, 3);
+  callCount = callCount + 1;
+};
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-obj-prop-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-obj-prop-id.js
new file mode 100644
index 0000000000..684eb38b2f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/ary-ptrn-rest-obj-prop-id.js
@@ -0,0 +1,49 @@
+// |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-decl.template
+/*---
+description: Rest element containing an object binding pattern (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([...{ 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/statements/async-generator/dstr/browser.js b/js/src/tests/test262/language/statements/async-generator/dstr/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/browser.js
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-init-iter-close.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-init-iter-close.js
new file mode 100644
index 0000000000..6414b85cc5
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-init-iter-close.js
@@ -0,0 +1,52 @@
+// |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-decl-dflt.template
+/*---
+description: Iterator is closed when not exhausted by pattern evaluation (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/dflt-ary-init-iter-get-err-array-prototype.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-init-iter-get-err-array-prototype.js
new file mode 100644
index 0000000000..1a56240ee1
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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];
+
+
+async function* f([x, y, z] = [1, 2, 3]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-init-iter-get-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-init-iter-get-err.js
new file mode 100644
index 0000000000..de44a6cc57
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Abrupt completion returned by GetIterator (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+};
+
+
+async function* f([x] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-init-iter-no-close.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-init-iter-no-close.js
new file mode 100644
index 0000000000..e8e41b61f0
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-init-iter-no-close.js
@@ -0,0 +1,52 @@
+// |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-decl-dflt.template
+/*---
+description: Iterator is not closed when exhausted by pattern evaluation (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/dflt-ary-name-iter-val.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-name-iter-val.js
new file mode 100644
index 0000000000..8465a02be4
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-name-iter-val.js
@@ -0,0 +1,51 @@
+// |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-decl-dflt.template
+/*---
+description: SingleNameBinding with normal value iteration (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-init.js
new file mode 100644
index 0000000000..b1767c07f9
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-init.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-init.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+async function* f([[x, y, z] = [4, 5, 6]] = []) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-iter.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-iter.js
new file mode 100644
index 0000000000..23964a3413
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elem-iter.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-iter.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+async function* f([[x, y, z] = [4, 5, 6]] = [[7, 8, 9]]) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, 8);
+  assert.sameValue(z, 9);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-init.js
new file mode 100644
index 0000000000..0f5d51e217
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-init.js
@@ -0,0 +1,50 @@
+// |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-decl-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([[,] = g()] = []) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-iter.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-iter.js
new file mode 100644
index 0000000000..dc8b97e069
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-elision-iter.js
@@ -0,0 +1,47 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-iter.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var callCount = 0;
+function* g() {
+  callCount += 1;
+};
+
+
+var callCount = 0;
+async function* f([[,] = g()] = [[]]) {
+  assert.sameValue(callCount, 0);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-init.js
new file mode 100644
index 0000000000..c86116e893
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-init.js
@@ -0,0 +1,46 @@
+// |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-decl-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([[] = 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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-iter.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-iter.js
new file mode 100644
index 0000000000..bd28dd3256
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-empty-iter.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-iter.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var initCount = 0;
+
+
+var callCount = 0;
+async function* f([[] = function() { initCount += 1; }()] = [[23]]) {
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-init.js
new file mode 100644
index 0000000000..52d1b56404
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-init.js
@@ -0,0 +1,47 @@
+// |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-decl-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([[...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/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-iter.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-iter.js
new file mode 100644
index 0000000000..87d6e440ae
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-rest-iter.js
@@ -0,0 +1,50 @@
+// |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-decl-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([[...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/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-val-null.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-ary-val-null.js
new file mode 100644
index 0000000000..07776a80c7
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Nested array destructuring with a null value (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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).
+---*/
+
+
+async function* f([[x]] = [null]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-exhausted.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-exhausted.js
new file mode 100644
index 0000000000..cd7012022b
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-exhausted.js
@@ -0,0 +1,42 @@
+// |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-decl-dflt.template
+/*---
+description: Destructuring initializer with an exhausted iterator (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-arrow.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..5618b6127c
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-arrow.js
@@ -0,0 +1,43 @@
+// |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-decl-dflt.template
+/*---
+description: SingleNameBinding does assign name to arrow functions (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-class.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-class.js
new file mode 100644
index 0000000000..f8af995ee3
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-class.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-class.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-cover.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..a7a2ac2817
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-cover.js
@@ -0,0 +1,44 @@
+// |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-decl-dflt.template
+/*---
+description: SingleNameBinding does assign name to "anonymous" functions "through" cover grammar (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-fn.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..29cb41fcc3
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-fn.js
@@ -0,0 +1,44 @@
+// |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-decl-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-gen.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..9e06b9f8d5
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-fn-name-gen.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-gen.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-hole.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-hole.js
new file mode 100644
index 0000000000..06d9249510
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-hole.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-hole.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Destructuring initializer with a "hole" (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    SingleNameBinding : BindingIdentifier Initializeropt
+    [...] 6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v). 8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+async function* f([x = 23] = [,]) {
+  assert.sameValue(x, 23);
+  // another statement
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-skipped.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-skipped.js
new file mode 100644
index 0000000000..4ac8a44b1d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-skipped.js
@@ -0,0 +1,47 @@
+// |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-decl-dflt.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-throws.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-throws.js
new file mode 100644
index 0000000000..21664b01a2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Destructuring initializer returns an abrupt completion (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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).
+---*/
+
+
+async function* f([x = (function() { throw new Test262Error(); })()] = [undefined]) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-undef.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-undef.js
new file mode 100644
index 0000000000..d65d474711
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-undef.js
@@ -0,0 +1,41 @@
+// |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-decl-dflt.template
+/*---
+description: Destructuring initializer with an undefined value (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-unresolvable.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-init-unresolvable.js
new file mode 100644
index 0000000000..fafba0dda8
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f([ x = unresolvableReference ] = []) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-complete.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-complete.js
new file mode 100644
index 0000000000..c1e0cdc1cb
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-complete.js
@@ -0,0 +1,45 @@
+// |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-decl-dflt.template
+/*---
+description: SingleNameBinding when value iteration completes (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([x] = []) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-done.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-done.js
new file mode 100644
index 0000000000..ac2460e888
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-done.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-done.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+async function* f([_, x] = []) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-step-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-step-err.js
new file mode 100644
index 0000000000..8c48978994
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+    }
+  };
+};
+
+
+async function* f([x] = g) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val-array-prototype.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val-array-prototype.js
new file mode 100644
index 0000000000..ea16359a78
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val-array-prototype.js
@@ -0,0 +1,61 @@
+// |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-decl-dflt.template
+/*---
+description: Array destructuring uses overriden Array.prototype[Symbol.iterator] (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val-err.js
new file mode 100644
index 0000000000..b35c1aae02
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+    }
+  };
+};
+
+
+async function* f([x] = g) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val.js
new file mode 100644
index 0000000000..25876266b0
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-id-iter-val.js
@@ -0,0 +1,51 @@
+// |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-decl-dflt.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-id-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-id-init.js
new file mode 100644
index 0000000000..0b777e4c10
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-id-init.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id-init.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+async function* f([{ x, y, z } = { x: 44, y: 55, z: 66 }] = []) {
+  assert.sameValue(x, 44);
+  assert.sameValue(y, 55);
+  assert.sameValue(z, 66);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-id.js
new file mode 100644
index 0000000000..32510ad6ff
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-id.js
@@ -0,0 +1,43 @@
+// |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-decl-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([{ 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/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id-init.js
new file mode 100644
index 0000000000..5a8c4cf500
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id-init.js
@@ -0,0 +1,53 @@
+// |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-decl-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([{ 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/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id.js
new file mode 100644
index 0000000000..e1894c266d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-prop-id.js
@@ -0,0 +1,53 @@
+// |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-decl-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([{ 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/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-val-null.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-val-null.js
new file mode 100644
index 0000000000..b1da8b1b5f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Nested object destructuring with a null value (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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).
+---*/
+
+
+async function* f([{ x }] = [null]) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-val-undef.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elem-obj-val-undef.js
new file mode 100644
index 0000000000..98f8e419ac
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Nested object destructuring with a value of `undefined` (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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).
+---*/
+
+
+async function* f([{ x }] = []) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elision-exhausted.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elision-exhausted.js
new file mode 100644
index 0000000000..36ee1dd508
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elision-exhausted.js
@@ -0,0 +1,48 @@
+// |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-decl-dflt.template
+/*---
+description: Elision accepts exhausted iterator (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([,] = 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/statements/async-generator/dstr/dflt-ary-ptrn-elision-step-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elision-step-err.js
new file mode 100644
index 0000000000..7961fd0631
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Elision advances iterator and forwards abrupt completions (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+}();
+
+
+async function* f([,] = 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/statements/async-generator/dstr/dflt-ary-ptrn-elision.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elision.js
new file mode 100644
index 0000000000..d6b839cf5c
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-elision.js
@@ -0,0 +1,57 @@
+// |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-decl-dflt.template
+/*---
+description: Elision advances iterator (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([,] = g()) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-empty.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-empty.js
new file mode 100644
index 0000000000..8d415e85d6
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-empty.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: No iteration occurs for an "empty" array binding pattern (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+async function* f([] = iter) {
+  assert.sameValue(iterations, 0);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-elem.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-elem.js
new file mode 100644
index 0000000000..d59f9184cf
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-elem.js
@@ -0,0 +1,64 @@
+// |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-decl-dflt.template
+/*---
+description: Rest element containing an array BindingElementList pattern (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([...[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/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-elision.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-elision.js
new file mode 100644
index 0000000000..74ce17b637
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-elision.js
@@ -0,0 +1,70 @@
+// |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-decl-dflt.template
+/*---
+description: Rest element containing an elision (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([...[,]] = 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/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-empty.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-empty.js
new file mode 100644
index 0000000000..534fee7f9e
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-empty.js
@@ -0,0 +1,53 @@
+// |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-decl-dflt.template
+/*---
+description: Rest element containing an "empty" array pattern (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([...[]] = iter) {
+  assert.sameValue(iterations, 1);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-rest.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-rest.js
new file mode 100644
index 0000000000..97ef5cf592
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-ary-rest.js
@@ -0,0 +1,49 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-rest.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Rest element containing a rest element (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+async function* f([...[...x]] = values) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-direct.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-direct.js
new file mode 100644
index 0000000000..20ab4e6e64
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-direct.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-direct.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Lone rest element (direct binding) (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+includes: [compareArray.js]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingIdentifier
+
+    [...]
+    2. Let A be ! ArrayCreate(0).
+    3. Let n be 0.
+    4. Repeat,
+        [...]
+        f. Perform ! CreateDataPropertyOrThrow(A, ! ToString(n), nextValue).
+        g. Set n to n + 1.
+
+---*/
+
+
+var callCount = 0;
+async function* f([...x] = [1]) {
+  assert(Array.isArray(x));
+  assert.compareArray(x, [1]);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-elision-next-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-elision-next-err.js
new file mode 100644
index 0000000000..3b681e70e2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Rest element following elision elements (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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(); })();
+
+
+async function* f([, ...x] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-elision.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-elision.js
new file mode 100644
index 0000000000..a3a71900f0
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-elision.js
@@ -0,0 +1,45 @@
+// |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-decl-dflt.template
+/*---
+description: Rest element following elision elements (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([ , , ...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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-exhausted.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-exhausted.js
new file mode 100644
index 0000000000..0dd8596944
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-exhausted.js
@@ -0,0 +1,41 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-exhausted.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: RestElement applied to an exhausted iterator (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. If environment is undefined, return PutValue(lhs, A).
+          ii. Return InitializeReferencedBinding(lhs, A).
+
+---*/
+
+
+var callCount = 0;
+async function* f([, , ...x] = [1, 2]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 0);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-iter-step-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-iter-step-err.js
new file mode 100644
index 0000000000..77cd5280ed
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Error forwarding when IteratorStep returns an abrupt completion (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+}();
+
+
+async function* f([...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/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-iter-val-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id-iter-val-err.js
new file mode 100644
index 0000000000..daea98a488
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Error forwarding when IteratorValue returns an abrupt completion (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [Symbol.iterator, async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+    }
+  };
+};
+
+
+async function* f([...x] = iter) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id.js
new file mode 100644
index 0000000000..39b0da8701
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-id.js
@@ -0,0 +1,42 @@
+// |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-decl-dflt.template
+/*---
+description: Lone rest element (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([...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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-init-ary.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-init-ary.js
new file mode 100644
index 0000000000..4ce335cf4e
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-init-ary.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-ary.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Rest element (nested array pattern) does not support initializer (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...[ x ] = []] = []) {
+  
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-init-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-init-id.js
new file mode 100644
index 0000000000..9b4c9810e3
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-init-id.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-id.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Rest element (identifier) does not support initializer (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...x = []] = []) {
+  
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-init-obj.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-init-obj.js
new file mode 100644
index 0000000000..215054fba8
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-init-obj.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-obj.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Rest element (nested object pattern) does not support initializer (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...{ x } = []] = []) {
+  
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-not-final-ary.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-not-final-ary.js
new file mode 100644
index 0000000000..30829b32c1
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-not-final-ary.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-ary.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Rest element (array binding pattern) may not be followed by any element (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...[x], y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-not-final-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-not-final-id.js
new file mode 100644
index 0000000000..61dc0c55af
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-not-final-id.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-id.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Rest element (identifier) may not be followed by any element (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...x, y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-not-final-obj.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-not-final-obj.js
new file mode 100644
index 0000000000..b968e3a5c9
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-not-final-obj.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-obj.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Rest element (object binding pattern) may not be followed by any element (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+async function* f([...{ x }, y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-obj-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-obj-id.js
new file mode 100644
index 0000000000..22573b9f72
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-obj-id.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-id.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Rest element containing an object binding pattern (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+
+
+var callCount = 0;
+async function* f([...{ length }] = [1, 2, 3]) {
+  assert.sameValue(length, 3);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-obj-prop-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-obj-prop-id.js
new file mode 100644
index 0000000000..1ec00fde2f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-ary-ptrn-rest-obj-prop-id.js
@@ -0,0 +1,49 @@
+// |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-decl-dflt.template
+/*---
+description: Rest element containing an object binding pattern (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f([...{ 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/statements/async-generator/dstr/dflt-obj-init-null.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-init-null.js
new file mode 100644
index 0000000000..7666e0fee3
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (null) (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+async function* f({} = null) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-init-undefined.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-init-undefined.js
new file mode 100644
index 0000000000..72af21f978
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (undefined) (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+async function* f({} = undefined) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-empty.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-empty.js
new file mode 100644
index 0000000000..d09c56d7bb
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-empty.js
@@ -0,0 +1,41 @@
+// |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-decl-dflt.template
+/*---
+description: No property access occurs for an "empty" object binding pattern (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({} = 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/statements/async-generator/dstr/dflt-obj-ptrn-id-get-value-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-get-value-err.js
new file mode 100644
index 0000000000..eca4bc75ab
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+  }
+});
+
+
+async function* f({ poisoned } = poisonedProperty) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-arrow.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..305dd74e47
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-arrow.js
@@ -0,0 +1,42 @@
+// |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-decl-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to arrow functions (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-class.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-class.js
new file mode 100644
index 0000000000..4c1ffddfc3
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-class.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-class.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-cover.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..27a82ff7ef
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-cover.js
@@ -0,0 +1,43 @@
+// |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-decl-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" functions "through" cover grammar (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-fn.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..98a366aa31
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-fn.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+async function* f({ fn = function () {}, xFn = function x() {} } = {}) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-gen.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..4496b1a371
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-fn-name-gen.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-gen.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-skipped.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-skipped.js
new file mode 100644
index 0000000000..f16fd9dde4
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-skipped.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    [...]
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+async function* f({ w = counter(), x = counter(), y = counter(), z = counter() } = { w: null, x: 0, y: false, z: '' }) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-throws.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-throws.js
new file mode 100644
index 0000000000..50b1cf0c36
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Error thrown when evaluating the initializer (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+}
+
+
+async function* f({ x = thrower() } = {}) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-unresolvable.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-init-unresolvable.js
new file mode 100644
index 0000000000..b15b7359c3
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f({ x = unresolvableReference } = {}) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-trailing-comma.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-trailing-comma.js
new file mode 100644
index 0000000000..be253e56a2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-id-trailing-comma.js
@@ -0,0 +1,36 @@
+// |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-decl-dflt.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+async function* f({ 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/statements/async-generator/dstr/dflt-obj-ptrn-list-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-list-err.js
new file mode 100644
index 0000000000..75d1b49d22
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Binding property list evaluation is interrupted by an abrupt completion (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+}
+
+
+async function* f({ 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/statements/async-generator/dstr/dflt-obj-ptrn-prop-ary-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-ary-init.js
new file mode 100644
index 0000000000..6b7db21671
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-ary-init.js
@@ -0,0 +1,45 @@
+// |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-decl-dflt.template
+/*---
+description: Object binding pattern with "nested" array binding pattern using initializer (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-ary-trailing-comma.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-ary-trailing-comma.js
new file mode 100644
index 0000000000..44112cd71b
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-ary-trailing-comma.js
@@ -0,0 +1,36 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+async function* f({ x: [y], } = { x: [45] }) {
+  assert.sameValue(y,45);
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-ary-value-null.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-ary-value-null.js
new file mode 100644
index 0000000000..118f16b3e8
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Object binding pattern with "nested" array binding pattern taking the `null` value (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f({ 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/statements/async-generator/dstr/dflt-obj-ptrn-prop-ary.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-ary.js
new file mode 100644
index 0000000000..552d85c163
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-ary.js
@@ -0,0 +1,43 @@
+// |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-decl-dflt.template
+/*---
+description: Object binding pattern with "nested" array binding pattern not using initializer (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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/statements/async-generator/dstr/dflt-obj-ptrn-prop-eval-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-eval-err.js
new file mode 100644
index 0000000000..f5e611718d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Evaluation of property name returns an abrupt completion (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+}
+
+
+async function* f({ [thrower()]: x } = {}) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-get-value-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-get-value-err.js
new file mode 100644
index 0000000000..ef6f3f23e2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+  }
+});
+
+
+async function* f({ poisoned: x = ++initEvalCount } = poisonedProperty) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+assert.sameValue(initEvalCount, 0);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-init-skipped.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-init-skipped.js
new file mode 100644
index 0000000000..edcc87ceb3
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-init-skipped.js
@@ -0,0 +1,58 @@
+// |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-decl-dflt.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-init-throws.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-init-throws.js
new file mode 100644
index 0000000000..b0814dabfe
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Error thrown when evaluating the initializer (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+}
+
+
+async function* f({ x: y = thrower() } = {}) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-init-unresolvable.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-init-unresolvable.js
new file mode 100644
index 0000000000..74ef7127dd
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f({ x: y = unresolvableReference } = {}) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-init.js
new file mode 100644
index 0000000000..5edab18821
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-init.js
@@ -0,0 +1,39 @@
+// |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-decl-dflt.template
+/*---
+description: Binding as specified via property name, identifier, and initializer (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-trailing-comma.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-trailing-comma.js
new file mode 100644
index 0000000000..308f9f5aca
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id-trailing-comma.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+async function* f({ x: y, } = { x: 23 }) {
+  assert.sameValue(y, 23);
+
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id.js
new file mode 100644
index 0000000000..660995b69d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-id.js
@@ -0,0 +1,39 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Binding as specified via property name and identifier (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+async function* f({ x: y } = { x: 23 }) {
+  assert.sameValue(y, 23);
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-obj-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-obj-init.js
new file mode 100644
index 0000000000..62ed8e5e15
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-obj-init.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-init.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern using initializer (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+async function* f({ w: { x, y, z } = { x: 4, y: 5, z: 6 } } = { w: undefined }) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-obj-value-null.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-obj-value-null.js
new file mode 100644
index 0000000000..7d4681cde7
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f({ 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/statements/async-generator/dstr/dflt-obj-ptrn-prop-obj-value-undef.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-obj-value-undef.js
new file mode 100644
index 0000000000..a241147697
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f({ w: { x, y, z } = undefined } = { }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f();
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-obj.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-obj.js
new file mode 100644
index 0000000000..4e1490ec4d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-prop-obj.js
@@ -0,0 +1,43 @@
+// |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-decl-dflt.template
+/*---
+description: Object binding pattern with "nested" object binding pattern not using initializer (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-rest-getter.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-rest-getter.js
new file mode 100644
index 0000000000..4cfe3fafe0
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-rest-getter.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-getter.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Getter is called when obj is being deconstructed to a rest Object (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+---*/
+var count = 0;
+
+
+var callCount = 0;
+async function* f({...x} = { get v() { count++; return 2; } }) {
+  assert.sameValue(count, 1);
+
+  verifyProperty(x, "v", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-rest-skip-non-enumerable.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-rest-skip-non-enumerable.js
new file mode 100644
index 0000000000..3563a9ae17
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-rest-skip-non-enumerable.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-skip-non-enumerable.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Rest object doesn't contain non-enumerable properties (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+---*/
+var o = {a: 3, b: 4};
+Object.defineProperty(o, "x", { value: 4, enumerable: false });
+
+
+var callCount = 0;
+async function* f({...rest} = o) {
+  assert.sameValue(rest.x, undefined);
+
+  verifyProperty(rest, "a", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 3
+  });
+
+  verifyProperty(rest, "b", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 4
+  });
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-rest-val-obj.js b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-rest-val-obj.js
new file mode 100644
index 0000000000..a5a3e3b2ca
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/dflt-obj-ptrn-rest-val-obj.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-val-obj.case
+// - src/dstr-binding/default/async-gen-func-decl-dflt.template
+/*---
+description: Rest object contains just unextracted data (async generator function declaration (default parameter))
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+---*/
+
+
+var callCount = 0;
+async function* f({a, b, ...rest} = {x: 1, y: 2, a: 5, b: 3}) {
+  assert.sameValue(rest.a, undefined);
+  assert.sameValue(rest.b, undefined);
+
+  verifyProperty(rest, "x", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 1
+  });
+
+  verifyProperty(rest, "y", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-init-null.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-init-null.js
new file mode 100644
index 0000000000..deeb256b6e
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (null) (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+async function* f({}) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f(null);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-init-undefined.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-init-undefined.js
new file mode 100644
index 0000000000..f04f037892
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Value specifed for object binding pattern must be object coercible (undefined) (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+
+
+async function* f({}) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f(undefined);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-empty.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-empty.js
new file mode 100644
index 0000000000..23428d35f0
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-empty.js
@@ -0,0 +1,41 @@
+// |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-decl.template
+/*---
+description: No property access occurs for an "empty" object binding pattern (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({}) {
+  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/statements/async-generator/dstr/obj-ptrn-id-get-value-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-get-value-err.js
new file mode 100644
index 0000000000..1795f3cc65
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+  }
+});
+
+
+async function* f({ poisoned }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(poisonedProperty);
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-arrow.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-arrow.js
new file mode 100644
index 0000000000..237d5f9694
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-arrow.js
@@ -0,0 +1,42 @@
+// |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-decl.template
+/*---
+description: SingleNameBinding assigns `name` to arrow functions (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-class.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-class.js
new file mode 100644
index 0000000000..e272d987e0
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-class.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-class.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-cover.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-cover.js
new file mode 100644
index 0000000000..6389dbcb7d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-cover.js
@@ -0,0 +1,43 @@
+// |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-decl.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" functions "through" cover grammar (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-fn.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-fn.js
new file mode 100644
index 0000000000..1ccd8761ae
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-fn.js
@@ -0,0 +1,43 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+async function* f({ fn = function () {}, xFn = function x() {} }) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-gen.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-gen.js
new file mode 100644
index 0000000000..c9679afdfc
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-fn-name-gen.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+
+---*/
+
+
+var callCount = 0;
+async function* f({ gen = function* () {}, xGen = function* x() {} }) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+f({}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-skipped.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-skipped.js
new file mode 100644
index 0000000000..3770316b3d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-skipped.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    [...]
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+async function* f({ w = counter(), x = counter(), y = counter(), z = counter() }) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+f({ w: null, x: 0, y: false, z: '' }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-throws.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-throws.js
new file mode 100644
index 0000000000..34eda335f8
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Error thrown when evaluating the initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+}
+
+
+async function* f({ x = thrower() }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-unresolvable.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-init-unresolvable.js
new file mode 100644
index 0000000000..3e8e754b26
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f({ x = unresolvableReference }) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-trailing-comma.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-trailing-comma.js
new file mode 100644
index 0000000000..3fb2d68313
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-id-trailing-comma.js
@@ -0,0 +1,36 @@
+// |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-decl.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+async function* f({ 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/statements/async-generator/dstr/obj-ptrn-list-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-list-err.js
new file mode 100644
index 0000000000..2eb05668ef
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Binding property list evaluation is interrupted by an abrupt completion (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+}
+
+
+async function* f({ 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/statements/async-generator/dstr/obj-ptrn-prop-ary-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-ary-init.js
new file mode 100644
index 0000000000..0f9f618d41
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-ary-init.js
@@ -0,0 +1,45 @@
+// |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-decl.template
+/*---
+description: Object binding pattern with "nested" array binding pattern using initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-ary-trailing-comma.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-ary-trailing-comma.js
new file mode 100644
index 0000000000..8739c17c46
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-ary-trailing-comma.js
@@ -0,0 +1,36 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+async function* f({ x: [y], }) {
+  assert.sameValue(y,45);
+  callCount = callCount + 1;
+};
+f({ x: [45] }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-ary-value-null.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-ary-value-null.js
new file mode 100644
index 0000000000..0ce6940358
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Object binding pattern with "nested" array binding pattern taking the `null` value (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f({ 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/statements/async-generator/dstr/obj-ptrn-prop-ary.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-ary.js
new file mode 100644
index 0000000000..121f6a935d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-ary.js
@@ -0,0 +1,43 @@
+// |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-decl.template
+/*---
+description: Object binding pattern with "nested" array binding pattern not using initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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/statements/async-generator/dstr/obj-ptrn-prop-eval-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-eval-err.js
new file mode 100644
index 0000000000..83da8522d1
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Evaluation of property name returns an abrupt completion (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+}
+
+
+async function* f({ [thrower()]: x }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-get-value-err.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-get-value-err.js
new file mode 100644
index 0000000000..dbbae145d7
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Error thrown when accessing the corresponding property of the value object (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+  }
+});
+
+
+async function* f({ poisoned: x = ++initEvalCount }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f(poisonedProperty);
+});
+
+assert.sameValue(initEvalCount, 0);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-init-skipped.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-init-skipped.js
new file mode 100644
index 0000000000..70d3ccd06c
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-init-skipped.js
@@ -0,0 +1,58 @@
+// |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-decl.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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/statements/async-generator/dstr/obj-ptrn-prop-id-init-throws.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-init-throws.js
new file mode 100644
index 0000000000..eca60f73b4
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Error thrown when evaluating the initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+}
+
+
+async function* f({ x: y = thrower() }) {
+  
+};
+
+assert.throws(Test262Error, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-init-unresolvable.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-init-unresolvable.js
new file mode 100644
index 0000000000..302e84b74c
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Destructuring initializer is an unresolvable reference (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f({ x: y = unresolvableReference }) {
+  
+};
+
+assert.throws(ReferenceError, function() {
+  f({});
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-init.js
new file mode 100644
index 0000000000..f93d9daeb7
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-init.js
@@ -0,0 +1,39 @@
+// |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-decl.template
+/*---
+description: Binding as specified via property name, identifier, and initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-trailing-comma.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-trailing-comma.js
new file mode 100644
index 0000000000..e938f19afc
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id-trailing-comma.js
@@ -0,0 +1,40 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+async function* f({ x: y, }) {
+  assert.sameValue(y, 23);
+
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+f({ x: 23 }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id.js
new file mode 100644
index 0000000000..e7aa455720
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-id.js
@@ -0,0 +1,39 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-id.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Binding as specified via property name and identifier (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+async function* f({ x: y }) {
+  assert.sameValue(y, 23);
+  assert.throws(ReferenceError, function() {
+    x;
+  });
+  callCount = callCount + 1;
+};
+f({ x: 23 }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-obj-init.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-obj-init.js
new file mode 100644
index 0000000000..b3afb6e80d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-obj-init.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-obj-init.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Object binding pattern with "nested" object binding pattern using initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+async function* f({ w: { x, y, z } = { x: 4, y: 5, z: 6 } }) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+f({ w: undefined }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-obj-value-null.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-obj-value-null.js
new file mode 100644
index 0000000000..7685385e43
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f({ 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/statements/async-generator/dstr/obj-ptrn-prop-obj-value-undef.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-obj-value-undef.js
new file mode 100644
index 0000000000..17a2359eaf
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/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-decl.template
+/*---
+description: Object binding pattern with "nested" object binding pattern taking the `null` value (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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.
+---*/
+
+
+async function* f({ w: { x, y, z } = undefined }) {
+  
+};
+
+assert.throws(TypeError, function() {
+  f({ });
+});
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-obj.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-obj.js
new file mode 100644
index 0000000000..6656224cd8
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-prop-obj.js
@@ -0,0 +1,43 @@
+// |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-decl.template
+/*---
+description: Object binding pattern with "nested" object binding pattern not using initializer (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f({ 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, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-rest-getter.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-rest-getter.js
new file mode 100644
index 0000000000..b68d00047c
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-rest-getter.js
@@ -0,0 +1,38 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-getter.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Getter is called when obj is being deconstructed to a rest Object (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+---*/
+var count = 0;
+
+
+var callCount = 0;
+async function* f({...x}) {
+  assert.sameValue(count, 1);
+
+  verifyProperty(x, "v", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+f({ get v() { count++; return 2; } }).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-rest-skip-non-enumerable.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-rest-skip-non-enumerable.js
new file mode 100644
index 0000000000..14ade21962
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-rest-skip-non-enumerable.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-skip-non-enumerable.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Rest object doesn't contain non-enumerable properties (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+---*/
+var o = {a: 3, b: 4};
+Object.defineProperty(o, "x", { value: 4, enumerable: false });
+
+
+var callCount = 0;
+async function* f({...rest}) {
+  assert.sameValue(rest.x, undefined);
+
+  verifyProperty(rest, "a", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 3
+  });
+
+  verifyProperty(rest, "b", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 4
+  });
+  callCount = callCount + 1;
+};
+f(o).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-rest-val-obj.js b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-rest-val-obj.js
new file mode 100644
index 0000000000..60b6b9e206
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/obj-ptrn-rest-val-obj.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-rest-val-obj.case
+// - src/dstr-binding/default/async-gen-func-decl.template
+/*---
+description: Rest object contains just unextracted data (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [object-rest, async-iteration]
+flags: [generated, async]
+includes: [propertyHelper.js]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+---*/
+
+
+var callCount = 0;
+async function* f({a, b, ...rest}) {
+  assert.sameValue(rest.a, undefined);
+  assert.sameValue(rest.b, undefined);
+
+  verifyProperty(rest, "x", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 1
+  });
+
+  verifyProperty(rest, "y", {
+    enumerable: true,
+    writable: true,
+    configurable: true,
+    value: 2
+  });
+  callCount = callCount + 1;
+};
+f({x: 1, y: 2, a: 5, b: 3}).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/dstr/shell.js b/js/src/tests/test262/language/statements/async-generator/dstr/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/dstr/shell.js
diff --git a/js/src/tests/test262/language/statements/async-generator/escaped-async.js b/js/src/tests/test262/language/statements/async-generator/escaped-async.js
new file mode 100644
index 0000000000..953409edfd
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/escaped-async.js
@@ -0,0 +1,25 @@
+// |reftest| error:SyntaxError
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-grammar-notation
+description: >
+  The `async` contextual keyword must not contain Unicode escape sequences.
+info: |
+  Terminal symbols are shown
+  in fixed width font, both in the productions of the grammars and throughout this
+  specification whenever the text directly refers to such a terminal symbol. These
+  are to appear in a script exactly as written. All terminal symbol code points
+  specified in this way are to be understood as the appropriate Unicode code points
+  from the Basic Latin range, as opposed to any similar-looking code points from
+  other Unicode ranges.
+negative:
+  phase: parse
+  type: SyntaxError
+features: [async-iteration]
+---*/
+
+$DONOTEVALUATE();
+
+\u0061sync function* f(){}
diff --git a/js/src/tests/test262/language/statements/async-generator/eval-var-scope-syntax-err.js b/js/src/tests/test262/language/statements/async-generator/eval-var-scope-syntax-err.js
new file mode 100644
index 0000000000..2711c015b4
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl.template
+/*---
+description: sloppy direct eval in params introduces var (async generator function declaration in sloppy code)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [default-parameters, async-iteration]
+flags: [generated, noStrict]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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;
+async function* f(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/statements/async-generator/forbidden-ext/b1/async-gen-func-decl-forbidden-ext-direct-access-prop-arguments.js b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b1/async-gen-func-decl-forbidden-ext-direct-access-prop-arguments.js
new file mode 100644
index 0000000000..2fba1e4405
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b1/async-gen-func-decl-forbidden-ext-direct-access-prop-arguments.js
@@ -0,0 +1,38 @@
+// |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-decl.template
+/*---
+description: Forbidden extension, f.arguments (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorDeclaration : 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;
+async function* f() {
+  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/statements/async-generator/forbidden-ext/b1/async-gen-func-decl-forbidden-ext-direct-access-prop-caller.js b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b1/async-gen-func-decl-forbidden-ext-direct-access-prop-caller.js
new file mode 100644
index 0000000000..d791f45a6f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b1/async-gen-func-decl-forbidden-ext-direct-access-prop-caller.js
@@ -0,0 +1,38 @@
+// |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-decl.template
+/*---
+description: Forbidden extension, o.caller (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorDeclaration : 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;
+async function* f() {
+  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/statements/async-generator/forbidden-ext/b1/browser.js b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b1/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b1/browser.js
diff --git a/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b1/shell.js b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b1/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b1/shell.js
diff --git a/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/async-gen-func-decl-forbidden-ext-indirect-access-own-prop-caller-get.js b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/async-gen-func-decl-forbidden-ext-indirect-access-own-prop-caller-get.js
new file mode 100644
index 0000000000..c662810e41
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/async-gen-func-decl-forbidden-ext-indirect-access-own-prop-caller-get.js
@@ -0,0 +1,64 @@
+// |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-decl.template
+/*---
+description: Forbidden extension, o.caller (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorDeclaration : 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;
+async function* f() {
+  "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/statements/async-generator/forbidden-ext/b2/async-gen-func-decl-forbidden-ext-indirect-access-own-prop-caller-value.js b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/async-gen-func-decl-forbidden-ext-indirect-access-own-prop-caller-value.js
new file mode 100644
index 0000000000..d6e06a187c
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/async-gen-func-decl-forbidden-ext-indirect-access-own-prop-caller-value.js
@@ -0,0 +1,64 @@
+// |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-decl.template
+/*---
+description: Forbidden extension, o.caller (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorDeclaration : 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;
+async function* f() {
+  "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/statements/async-generator/forbidden-ext/b2/async-gen-func-decl-forbidden-ext-indirect-access-prop-caller.js b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/async-gen-func-decl-forbidden-ext-indirect-access-prop-caller.js
new file mode 100644
index 0000000000..e6de8ef013
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/async-gen-func-decl-forbidden-ext-indirect-access-prop-caller.js
@@ -0,0 +1,64 @@
+// |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-decl.template
+/*---
+description: Forbidden extension, o.caller (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [arrow-function, async-functions, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorDeclaration : 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;
+async function* f() {
+  "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/statements/async-generator/forbidden-ext/b2/browser.js b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/browser.js
diff --git a/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/shell.js b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/b2/shell.js
diff --git a/js/src/tests/test262/language/statements/async-generator/forbidden-ext/browser.js b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/browser.js
diff --git a/js/src/tests/test262/language/statements/async-generator/forbidden-ext/shell.js b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/forbidden-ext/shell.js
diff --git a/js/src/tests/test262/language/statements/async-generator/generator-created-after-decl-inst.js b/js/src/tests/test262/language/statements/async-generator/generator-created-after-decl-inst.js
new file mode 100644
index 0000000000..403a0b70fc
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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]
+---*/
+
+async function* g(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/statements/async-generator/object-destructuring-param-strict-body.js b/js/src/tests/test262/language/statements/async-generator/object-destructuring-param-strict-body.js
new file mode 100644
index 0000000000..cf3968ee69
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl.template
+/*---
+description: ObjectBindingPattern and Use Strict Directive are not allowed to coexist for the same function. (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [rest-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+
+
+async function* f({property}) {
+  "use strict";
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/params-trailing-comma-multiple.js b/js/src/tests/test262/language/statements/async-generator/params-trailing-comma-multiple.js
new file mode 100644
index 0000000000..6bd7572487
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/params-trailing-comma-multiple.js
@@ -0,0 +1,40 @@
+// |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-decl.template
+/*---
+description: A trailing comma should not increase the respective length, using multiple parameters (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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
+async function* ref(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, $DONE);
+
+assert.sameValue(ref.length, 2, 'length is properly set');
diff --git a/js/src/tests/test262/language/statements/async-generator/params-trailing-comma-single.js b/js/src/tests/test262/language/statements/async-generator/params-trailing-comma-single.js
new file mode 100644
index 0000000000..073dab2edb
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/params-trailing-comma-single.js
@@ -0,0 +1,39 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/params-trailing-comma-single.case
+// - src/function-forms/default/async-gen-func-decl.template
+/*---
+description: A trailing comma should not increase the respective length, using a single parameter (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody,
+            scope, strict).
+        [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] : FormalParameterList[?Yield, ?Await] ,
+---*/
+
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+async function* ref(a,) {
+  assert.sameValue(a, 42);
+  callCount = callCount + 1;
+}
+
+ref(42, 39).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator function invoked exactly once');
+}).then($DONE, $DONE);
+
+assert.sameValue(ref.length, 1, 'length is properly set');
diff --git a/js/src/tests/test262/language/statements/async-generator/rest-param-strict-body.js b/js/src/tests/test262/language/statements/async-generator/rest-param-strict-body.js
new file mode 100644
index 0000000000..5ea01c0c44
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl.template
+/*---
+description: RestParameter and Use Strict Directive are not allowed to coexist for the same function. (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [rest-parameters, async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+
+
+async function* f(a,...rest) {
+  "use strict";
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/rest-params-trailing-comma-early-error.js b/js/src/tests/test262/language/statements/async-generator/rest-params-trailing-comma-early-error.js
new file mode 100644
index 0000000000..758af25e8b
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-decl.template
+/*---
+description: It's a syntax error if a FunctionRestParameter is followed by a trailing comma (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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();
+
+
+async function* f(...a,) {
+  
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/return-undefined-implicit-and-explicit.js b/js/src/tests/test262/language/statements/async-generator/return-undefined-implicit-and-explicit.js
new file mode 100644
index 0000000000..75bc5dd2d1
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/return-undefined-implicit-and-explicit.js
@@ -0,0 +1,81 @@
+// |reftest| async
+// Copyright (C) 2019 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-return-statement-runtime-semantics-evaluation
+description: >
+  Return with an explicit return value awaits this value.
+info: |
+  13.10.1 Runtime Semantics: Evaluation
+
+    ReturnStatement : return;
+      1. Return Completion { [[Type]]: return, [[Value]]: undefined, [[Target]]: empty }.
+
+    ReturnStatement : return Expression ;
+      1. Let exprRef be the result of evaluating Expression.
+      2. Let exprValue be ? GetValue(exprRef).
+      3. If ! GetGeneratorKind() is async, set exprValue to ? Await(exprValue).
+      4. Return Completion { [[Type]]: return, [[Value]]: exprValue, [[Target]]: empty }.
+
+  25.5.3.2 AsyncGeneratorStart ( generator, generatorBody )
+
+    ...
+    5. Set the code evaluation state of genContext such that when evaluation is resumed for that
+       execution context the following steps will be performed:
+      a. Let result be the result of evaluating generatorBody.
+      ...
+      e. If result is a normal completion, let resultValue be undefined.
+      ...
+      g. Return ! AsyncGeneratorResolve(generator, resultValue, true).
+
+includes: [compareArray.js]
+flags: [async]
+features: [async-iteration]
+---*/
+
+// 25.5.3.2, step 5.e: |generatorBody| execution ends with a normal completion.
+async function* g1() {
+  // no return
+}
+
+// 13.10.1: No expression form means direct return.
+async function* g2() {
+  return;
+}
+
+// 13.10.1: Explicit expression requires Await.
+async function* g3() {
+  return undefined; // Return undefined via global value `undefined`.
+}
+
+// 13.10.1: Explicit expression requires Await.
+async function* g4() {
+  return void 0; // Return undefined via void expression.
+}
+
+var expected = [
+  "tick 1",
+
+  "g1 ret",
+  "g2 ret",
+
+  "tick 2",
+
+  "g3 ret",
+  "g4 ret",
+];
+
+var actual = [];
+
+Promise.resolve(0)
+  .then(() => actual.push("tick 1"))
+  .then(() => actual.push("tick 2"))
+  .then(() => {
+    assert.compareArray(actual, expected, "Ticks for implicit and explicit return undefined");
+}).then($DONE, $DONE);
+
+g1().next().then(v => actual.push("g1 ret"));
+g2().next().then(v => actual.push("g2 ret"));
+g3().next().then(v => actual.push("g3 ret"));
+g4().next().then(v => actual.push("g4 ret"));
diff --git a/js/src/tests/test262/language/statements/async-generator/shell.js b/js/src/tests/test262/language/statements/async-generator/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/shell.js
diff --git a/js/src/tests/test262/language/statements/async-generator/unscopables-with-in-nested-fn.js b/js/src/tests/test262/language/statements/async-generator/unscopables-with-in-nested-fn.js
new file mode 100644
index 0000000000..7c63a23776
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/unscopables-with-in-nested-fn.js
@@ -0,0 +1,82 @@
+// |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-decl.template
+/*---
+description: Symbol.unscopables behavior across scope boundaries (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [globalThis, Symbol.unscopables, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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
+async function* ref(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/statements/async-generator/unscopables-with.js b/js/src/tests/test262/language/statements/async-generator/unscopables-with.js
new file mode 100644
index 0000000000..791c40315f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/unscopables-with.js
@@ -0,0 +1,76 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/function-forms/unscopables-with.case
+// - src/function-forms/default/async-gen-func-decl.template
+/*---
+description: Symbol.unscopables behavior across scope boundaries (async generator function declaration)
+esid: sec-asyncgenerator-definitions-instantiatefunctionobject
+features: [globalThis, Symbol.unscopables, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier
+        ( FormalParameters ) { AsyncGeneratorBody }
+
+        [...]
+        3. Let F 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
+async function* ref(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, $DONE);
+
+  count++;
+}
+assert.sameValue(count, 6, 'The value of `count` is 6');
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-as-binding-identifier-escaped.js b/js/src/tests/test262/language/statements/async-generator/yield-as-binding-identifier-escaped.js
new file mode 100644
index 0000000000..866f682069
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-as-binding-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-binding-identifier-escaped.case
+// - src/async-generators/syntax/async-declaration.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+async function *gen() {
+  var yi\u0065ld;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-as-binding-identifier.js b/js/src/tests/test262/language/statements/async-generator/yield-as-binding-identifier.js
new file mode 100644
index 0000000000..8351c65c5d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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".
+
+---*/
+$DONOTEVALUATE();
+
+
+async function *gen() {
+  var yield;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-as-identifier-reference-escaped.js b/js/src/tests/test262/language/statements/async-generator/yield-as-identifier-reference-escaped.js
new file mode 100644
index 0000000000..951a7741b2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-as-identifier-reference-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-identifier-reference-escaped.case
+// - src/async-generators/syntax/async-declaration.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+async function *gen() {
+  void yi\u0065ld;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-as-identifier-reference.js b/js/src/tests/test262/language/statements/async-generator/yield-as-identifier-reference.js
new file mode 100644
index 0000000000..db16bf85e6
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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".
+
+---*/
+$DONOTEVALUATE();
+
+
+async function *gen() {
+  void yield;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-as-label-identifier-escaped.js b/js/src/tests/test262/language/statements/async-generator/yield-as-label-identifier-escaped.js
new file mode 100644
index 0000000000..a523fed8c9
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-as-label-identifier-escaped.js
@@ -0,0 +1,32 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-as-label-identifier-escaped.case
+// - src/async-generators/syntax/async-declaration.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a label identifier. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+
+async function *gen() {
+  yi\u0065ld: ;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-as-label-identifier.js b/js/src/tests/test262/language/statements/async-generator/yield-as-label-identifier.js
new file mode 100644
index 0000000000..78cbbb63ee
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a label identifier. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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".
+
+---*/
+$DONOTEVALUATE();
+
+
+async function *gen() {
+  yield: ;
+}
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-identifier-non-strict.js b/js/src/tests/test262/language/statements/async-generator/yield-identifier-non-strict.js
new file mode 100644
index 0000000000..d1d4c66c8d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-identifier-non-strict.js
@@ -0,0 +1,46 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-identifier-non-strict.case
+// - src/async-generators/non-strict/async-declaration.template
+/*---
+description: Use of yield as a valid identifier in a function body inside a generator body in non strict mode (Async generator function declaration - valid for non-strict only cases)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+
+
+var callCount = 0;
+
+async function *gen() {
+  callCount += 1;
+  return (function(arg) {
+      var yield = arg + 1;
+      return yield;
+    }(yield))
+}
+
+var iter = gen();
+
+var item = iter.next();
+
+item.then(({ done, value }) => {
+  assert.sameValue(done, false);
+  assert.sameValue(value, undefined);
+});
+
+item = iter.next(42);
+
+item.then(({ done, value }) => {
+  assert.sameValue(done, true);
+  assert.sameValue(value, 43);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-identifier-spread-non-strict.js b/js/src/tests/test262/language/statements/async-generator/yield-identifier-spread-non-strict.js
new file mode 100644
index 0000000000..ef3a5bcef0
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.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 function declaration - valid for non-strict only cases)
+esid: prod-AsyncGeneratorDeclaration
+features: [object-spread, Symbol, async-iteration]
+flags: [generated, noStrict, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Spread Properties
+
+    PropertyDefinition[Yield]:
+      (...)
+      ...AssignmentExpression[In, ?Yield]
+
+---*/
+var s = Symbol('s');
+
+
+var callCount = 0;
+
+async function *gen() {
+  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, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-identifier-spread-strict-strict.js b/js/src/tests/test262/language/statements/async-generator/yield-identifier-spread-strict-strict.js
new file mode 100644
index 0000000000..fd6e9a2fd8
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-identifier-spread-strict-strict.js
@@ -0,0 +1,48 @@
+// |reftest| error:SyntaxError
+'use strict';
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-identifier-spread-strict.case
+// - src/async-generators/default/async-declaration.template
+/*---
+description: It's an early error if the AssignmentExpression is a function body with yield as an identifier in strict mode. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [object-spread, async-iteration]
+flags: [generated, onlyStrict]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Spread Properties
+
+    PropertyDefinition[Yield]:
+      (...)
+      ...AssignmentExpression[In, ?Yield]
+
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+
+async function *gen() {
+  callCount += 1;
+  return {
+       ...(function() {
+          var yield;
+          throw new Test262Error();
+       }()),
+    }
+}
+
+var iter = gen();
+
+
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-identifier-strict-strict.js b/js/src/tests/test262/language/statements/async-generator/yield-identifier-strict-strict.js
new file mode 100644
index 0000000000..76ce9ef46d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: It's an early error if the generator body has another function body with yield as an identifier in strict mode. (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated, onlyStrict]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+$DONOTEVALUATE();
+
+
+var callCount = 0;
+
+async function *gen() {
+  callCount += 1;
+  (function() {
+      var yield;
+      throw new Test262Error();
+    }())
+}
+
+var iter = gen();
+
+
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-promise-reject-next-catch.js b/js/src/tests/test262/language/statements/async-generator/yield-promise-reject-next-catch.js
new file mode 100644
index 0000000000..c215587a00
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-promise-reject-next-catch.js
@@ -0,0 +1,44 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-catch.case
+// - src/async-generators/default/async-declaration.template
+/*---
+description: yield Promise.reject(value) is treated as throw value (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+
+
+var callCount = 0;
+
+async function *gen() {
+  callCount += 1;
+  yield Promise.reject(error);
+  yield "unreachable";
+}
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}).catch(rejectValue => {
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+});
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-promise-reject-next-for-await-of-async-iterator.js b/js/src/tests/test262/language/statements/async-generator/yield-promise-reject-next-for-await-of-async-iterator.js
new file mode 100644
index 0000000000..19d00d022f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-promise-reject-next-for-await-of-async-iterator.js
@@ -0,0 +1,50 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-promise-reject-next-for-await-of-async-iterator.case
+// - src/async-generators/default/async-declaration.template
+/*---
+description: yield * [Promise.reject(value)] is treated as throw value (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+async function * readFile() {
+  yield Promise.reject(error);
+  yield "unreachable";
+}
+
+
+var callCount = 0;
+
+async function *gen() {
+  callCount += 1;
+  for await (let line of readFile()) {
+    yield line;
+  }
+}
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error("Promise incorrectly resolved.");
+}, rejectValue => {
+
+  // yield Promise.reject(error);
+  assert.sameValue(rejectValue, error);
+
+  iter.next().then(({done, value}) => {
+    // iter is closed now.
+    assert.sameValue(done, true, "The value of IteratorResult.done is `true`");
+    assert.sameValue(value, undefined, "The value of IteratorResult.value is `undefined`");
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-promise-reject-next-for-await-of-sync-iterator.js b/js/src/tests/test262/language/statements/async-generator/yield-promise-reject-next-for-await-of-sync-iterator.js
new file mode 100644
index 0000000000..fa67f67422
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: yield Promise.reject(value) in for-await-of is treated as throw value (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+let iterable = [
+  Promise.reject(error),
+  "unreachable"
+];
+
+
+var callCount = 0;
+
+async function *gen() {
+  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/statements/async-generator/yield-promise-reject-next-yield-star-async-iterator.js b/js/src/tests/test262/language/statements/async-generator/yield-promise-reject-next-yield-star-async-iterator.js
new file mode 100644
index 0000000000..5c9d76f588
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: yield * (async iterator) is treated as throw value (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+async function * readFile() {
+  yield Promise.reject(error);
+  yield "unreachable";
+}
+
+
+var callCount = 0;
+
+async function *gen() {
+  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/statements/async-generator/yield-promise-reject-next-yield-star-sync-iterator.js b/js/src/tests/test262/language/statements/async-generator/yield-promise-reject-next-yield-star-sync-iterator.js
new file mode 100644
index 0000000000..d1833caa7e
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: yield * (async iterator) is treated as throw value (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+let iterable = [
+  Promise.reject(error),
+  "unreachable"
+];
+
+
+var callCount = 0;
+
+async function *gen() {
+  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/statements/async-generator/yield-promise-reject-next.js b/js/src/tests/test262/language/statements/async-generator/yield-promise-reject-next.js
new file mode 100644
index 0000000000..f4972beae6
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: yield Promise.reject(value) is treated as throw value (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+---*/
+let error = new Error();
+
+
+var callCount = 0;
+
+async function *gen() {
+  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/statements/async-generator/yield-return-then-getter-ticks.js b/js/src/tests/test262/language/statements/async-generator/yield-return-then-getter-ticks.js
new file mode 100644
index 0000000000..2a3b580a91
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-return-then-getter-ticks.js
@@ -0,0 +1,105 @@
+// |reftest| async
+// Copyright (C) 2019 André Bargull. 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: >
+  Return resumption value is awaited upon and hence is treated as a thenable.
+info: |
+  14.4.14 Runtime Semantics: Evaluation
+    YieldExpression : yield AssignmentExpression
+
+    ...
+    3. Let value be ? GetValue(exprRef).
+    4. If generatorKind is async, then return ? AsyncGeneratorYield(value).
+    ...
+
+  25.5.3.7 AsyncGeneratorYield ( value )
+    ...
+    5. Set value to ? Await(value).
+    ...
+    8. Set the code evaluation state of genContext such that when evaluation is resumed with a
+       Completion resumptionValue the following steps will be performed:
+      ...
+      b. Let awaited be Await(resumptionValue.[[Value]]).
+      ...
+      e. Return Completion { [[Type]]: return, [[Value]]: awaited.[[Value]], [[Target]]: empty }.
+      ...
+
+  6.2.3.1 Await
+    ...
+    2. Let promise be ? PromiseResolve(%Promise%, « value »).
+    ...
+
+  25.6.4.5.1 PromiseResolve ( C, x )
+    ...
+    3. Let promiseCapability be ? NewPromiseCapability(C).
+    4. Perform ? Call(promiseCapability.[[Resolve]], undefined, « x »).
+    ...
+
+  25.6.1.5 NewPromiseCapability ( C )
+    ...
+    7. Let promise be ? Construct(C, « executor »).
+    ...
+
+  25.6.3.1 Promise ( executor )
+    ...
+    8. Let resolvingFunctions be CreateResolvingFunctions(promise).
+    ...
+
+  25.6.1.3 CreateResolvingFunctions ( promise )
+    ...
+    2. Let stepsResolve be the algorithm steps defined in Promise Resolve Functions (25.6.1.3.2).
+    3. Let resolve be CreateBuiltinFunction(stepsResolve, « [[Promise]], [[AlreadyResolved]] »).
+    ...
+
+  25.6.1.3.2 Promise Resolve Functions
+    ...
+    9. Let then be Get(resolution, "then").
+    ...
+
+includes: [compareArray.js]
+flags: [async]
+features: [async-iteration]
+---*/
+
+var expected = [
+  "start",
+
+  // `Await(value)` promise resolved.
+  "tick 1",
+
+  // "then" of `resumptionValue.[[Value]]` accessed.
+  "get then",
+
+  // `Await(resumptionValue.[[Value]])` promise resolved.
+  "tick 2",
+];
+
+var actual = [];
+
+async function* f() {
+  actual.push("start");
+  yield 123;
+  actual.push("stop - never reached");
+}
+
+Promise.resolve(0)
+  .then(() => actual.push("tick 1"))
+  .then(() => actual.push("tick 2"))
+  .then(() => {
+    assert.compareArray(actual, expected, "Ticks for return with thenable getter");
+}).then($DONE, $DONE);
+
+var it = f();
+
+// Start generator execution.
+it.next();
+
+// Stop generator execution.
+it.return({
+  get then() {
+    actual.push("get then");
+  }
+});
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-spread-arr-multiple.js b/js/src/tests/test262/language/statements/async-generator/yield-spread-arr-multiple.js
new file mode 100644
index 0000000000..3f22543cca
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-spread-arr-multiple.js
@@ -0,0 +1,50 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-spread-arr-multiple.case
+// - src/async-generators/default/async-declaration.template
+/*---
+description: Use yield value in a array spread position (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated, async]
+includes: [compareArray.js]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Array Initializer
+
+    SpreadElement[Yield, Await]:
+      ...AssignmentExpression[+In, ?Yield, ?Await]
+
+---*/
+var arr = ['a', 'b', 'c'];
+var item;
+
+
+var callCount = 0;
+
+async function *gen() {
+  callCount += 1;
+  yield [...yield yield];
+}
+
+var iter = gen();
+
+iter.next(false);
+item = iter.next(['a', 'b', 'c']);
+
+item.then(({ done, value }) => {
+  item = iter.next(value);
+
+  item.then(({ done, value }) => {
+    assert.compareArray(value, arr);
+    assert.sameValue(done, false);
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-spread-arr-single.js b/js/src/tests/test262/language/statements/async-generator/yield-spread-arr-single.js
new file mode 100644
index 0000000000..c68224b07b
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Use yield value in a array spread position (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-spread-obj.js b/js/src/tests/test262/language/statements/async-generator/yield-spread-obj.js
new file mode 100644
index 0000000000..e5611226af
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-spread-obj.js
@@ -0,0 +1,52 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-spread-obj.case
+// - src/async-generators/default/async-declaration.template
+/*---
+description: Use yield value in a object spread position (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [object-spread, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    Spread Properties
+
+    PropertyDefinition[Yield]:
+      (...)
+      ...AssignmentExpression[In, ?Yield]
+
+---*/
+
+
+var callCount = 0;
+
+async function *gen() {
+  callCount += 1;
+  yield {
+      ...yield,
+      y: 1,
+      ...yield yield,
+    };
+}
+
+var iter = gen();
+
+iter.next();
+iter.next({ x: 42 });
+iter.next({ x: 'lol' });
+var item = iter.next({ y: 39 });
+
+item.then(({ done, value }) => {
+  assert.sameValue(value.x, 42);
+  assert.sameValue(value.y, 39);
+  assert.sameValue(Object.keys(value).length, 2);
+  assert.sameValue(done, false);
+}).then($DONE, $DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-star-async-from-sync-iterator-inaccessible.js b/js/src/tests/test262/language/statements/async-generator/yield-star-async-from-sync-iterator-inaccessible.js
new file mode 100644
index 0000000000..f962045044
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-star-async-from-sync-iterator-inaccessible.js
@@ -0,0 +1,56 @@
+// |reftest| async
+// Copyright (C) 2019 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-createasyncfromsynciterator
+description: >
+  Async-from-Sync Iterator instances are not accessible from user code.
+info: |
+  25.1.4.1 CreateAsyncFromSyncIterator ( syncIteratorRecord )
+    1. Let asyncIterator be ! ObjectCreate(%AsyncFromSyncIteratorPrototype%, « [[SyncIteratorRecord]] »).
+    2. Set asyncIterator.[[SyncIteratorRecord]] to syncIteratorRecord.
+    3. Let nextMethod be ! Get(asyncIterator, "next").
+    4. Let iteratorRecord be Record { [[Iterator]]: asyncIterator, [[NextMethod]]: nextMethod, [[Done]]: false }.
+    5. Return iteratorRecord.
+
+  14.4.14 Runtime Semantics: Evaluation
+    YieldExpression : yield * AssignmentExpression
+      1. Let generatorKind be ! GetGeneratorKind().
+      ...
+      4. Let iteratorRecord be ? GetIterator(value, generatorKind).
+      ...
+
+  7.4.1 GetIterator ( obj [ , hint [ , method ] ] )
+    ...
+    3. If method is not present, then
+      a. If hint is async, then
+        i. Set method to ? GetMethod(obj, @@asyncIterator).
+        ii. If method is undefined, then
+          1. Let syncMethod be ? GetMethod(obj, @@iterator).
+          2. Let syncIteratorRecord be ? GetIterator(obj, sync, syncMethod).
+          3. Return ? CreateAsyncFromSyncIterator(syncIteratorRecord).
+      ...
+
+flags: [async]
+features: [async-iteration]
+---*/
+
+var AsyncIteratorPrototype = Object.getPrototypeOf(async function*(){}.constructor.prototype.prototype);
+
+Object.defineProperty(AsyncIteratorPrototype, Symbol.iterator, {
+  get() {
+    throw new Error("@@iterator accessed");
+  }
+});
+
+Object.defineProperty(AsyncIteratorPrototype, Symbol.asyncIterator, {
+  get() {
+    throw new Error("@@asyncIterator accessed");
+  }
+});
+
+async function* g() {
+    yield* [];
+}
+g().next().then(() => $DONE(), $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-star-async-next.js b/js/src/tests/test262/language/statements/async-generator/yield-star-async-next.js
new file mode 100644
index 0000000000..155a5d02cd
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Execution order for yield* with async iterator and next() (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-async-return.js b/js/src/tests/test262/language/statements/async-generator/yield-star-async-return.js
new file mode 100644
index 0000000000..9e2c42bae3
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: execution order for yield* with async iterator and return() (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-async-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-async-throw.js
new file mode 100644
index 0000000000..465156fa18
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: execution order for yield* with async iterator and throw() (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-star-expr-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-expr-abrupt.js
new file mode 100644
index 0000000000..0c41b9ec6d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-star-expr-abrupt.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/async-generators/yield-star-expr-abrupt.case
+// - src/async-generators/default/async-declaration.template
+/*---
+description: Abrupt completion while getting yield* operand (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+
+    YieldExpression: yield * AssignmentExpression
+
+    1. Let exprRef be the result of evaluating AssignmentExpression.
+    2. Let value be ? GetValue(exprRef).
+    ...
+
+---*/
+var obj = {};
+var abrupt = function() {
+  throw obj;
+};
+
+
+
+var callCount = 0;
+
+async function *gen() {
+  callCount += 1;
+  yield* abrupt();
+    throw new Test262Error('abrupt completion closes iter');
+
+}
+
+var iter = gen();
+
+iter.next().then(() => {
+  throw new Test262Error('Promise incorrectly fulfilled.');
+}, v => {
+  assert.sameValue(v, obj, "reject reason");
+
+  iter.next().then(({ done, value }) => {
+    assert.sameValue(done, true, 'the iterator is completed');
+    assert.sameValue(value, undefined, 'value is undefined');
+  }).then($DONE, $DONE);
+}).catch($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-get-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-get-abrupt.js
new file mode 100644
index 0000000000..7796050a16
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Abrupt completion while getting [Symbol.asyncIterator] (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-not-callable-boolean-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-not-callable-boolean-throw.js
new file mode 100644
index 0000000000..5c5a180678
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (boolean) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-not-callable-number-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-not-callable-number-throw.js
new file mode 100644
index 0000000000..7fd8825b29
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (number) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-not-callable-object-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-not-callable-object-throw.js
new file mode 100644
index 0000000000..4d985ae446
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (object) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-not-callable-string-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-not-callable-string-throw.js
new file mode 100644
index 0000000000..19439f18f3
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (string) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-not-callable-symbol-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-not-callable-symbol-throw.js
new file mode 100644
index 0000000000..2d9cfc5c55
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.asyncIterator] (symbol) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-null-sync-get-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-null-sync-get-abrupt.js
new file mode 100644
index 0000000000..7bc93f03e6
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Abrupt completion while getting @@iterator after null @@asyncIterator (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-returns-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-returns-abrupt.js
new file mode 100644
index 0000000000..883bc0973f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Abrupt completion while calling [Symbol.asyncIterator] (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-returns-boolean-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-returns-boolean-throw.js
new file mode 100644
index 0000000000..cadf3d6496
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - boolean (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-returns-null-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-returns-null-throw.js
new file mode 100644
index 0000000000..81284e6d0b
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - null (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-returns-number-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-returns-number-throw.js
new file mode 100644
index 0000000000..e6688ecb7f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - number (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-returns-string-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-returns-string-throw.js
new file mode 100644
index 0000000000..92943314d9
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - string (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-returns-symbol-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-returns-symbol-throw.js
new file mode 100644
index 0000000000..ae3539c5e6
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - symbol (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-returns-undefined-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-returns-undefined-throw.js
new file mode 100644
index 0000000000..40aea77591
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.asyncIterator]() - undefined (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-async-undefined-sync-get-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-async-undefined-sync-get-abrupt.js
new file mode 100644
index 0000000000..ee81acbf34
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Abrupt completion while getting @@iterator after undefined @@asyncIterator (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-get-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-get-abrupt.js
new file mode 100644
index 0000000000..1bd3ca00ad
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Abrupt completion while getting [Symbol.iterator] (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-not-callable-boolean-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-not-callable-boolean-throw.js
new file mode 100644
index 0000000000..a87cfc0adf
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (boolean) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-not-callable-number-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-not-callable-number-throw.js
new file mode 100644
index 0000000000..aa32053600
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (number) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-not-callable-object-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-not-callable-object-throw.js
new file mode 100644
index 0000000000..0fa5e2d73c
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (object) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-not-callable-string-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-not-callable-string-throw.js
new file mode 100644
index 0000000000..86f31ce384
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (string) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-not-callable-symbol-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-not-callable-symbol-throw.js
new file mode 100644
index 0000000000..4bec50b862
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Throws a TypeError on a non-callable [Symbol.iterator] (symbol) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-returns-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-returns-abrupt.js
new file mode 100644
index 0000000000..c2094a328f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Abrupt completion while calling [Symbol.iterator] (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-returns-boolean-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-returns-boolean-throw.js
new file mode 100644
index 0000000000..327afe9fde
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.iterator]() - boolean (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-returns-null-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-returns-null-throw.js
new file mode 100644
index 0000000000..4b0e3cf33c
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.iterator]() - null (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-returns-number-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-returns-number-throw.js
new file mode 100644
index 0000000000..9cd51156c8
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.iterator]() - number (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-returns-string-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-returns-string-throw.js
new file mode 100644
index 0000000000..1ce242fde1
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.iterator]() - string (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-returns-symbol-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-returns-symbol-throw.js
new file mode 100644
index 0000000000..6f87f06bc8
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.iterator]() - symbol (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-getiter-sync-returns-undefined-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-getiter-sync-returns-undefined-throw.js
new file mode 100644
index 0000000000..71c01c4e0f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Non object returned by [Symbol.iterator]() - undefined (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-call-done-get-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-call-done-get-abrupt.js
new file mode 100644
index 0000000000..9bc62c10fd
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Abrupt completion while getting done (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-call-returns-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-call-returns-abrupt.js
new file mode 100644
index 0000000000..8ca899a840
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Abrupt completion while calling next (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-call-value-get-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-call-value-get-abrupt.js
new file mode 100644
index 0000000000..033348b08d
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Abrupt completion while getting value (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-get-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-get-abrupt.js
new file mode 100644
index 0000000000..e1d269458e
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Abrupt completion while getting next (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-non-object-ignores-then.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-non-object-ignores-then.js
new file mode 100644
index 0000000000..271fa593c9
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: If next() value is not-object, do not access respective then property (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-not-callable-boolean-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-not-callable-boolean-throw.js
new file mode 100644
index 0000000000..cd7b5607ba
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Not-callable next value in a yield star position - boolean (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-not-callable-null-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-not-callable-null-throw.js
new file mode 100644
index 0000000000..88662200ce
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Not-callable next value in a yield star position - null (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-not-callable-number-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-not-callable-number-throw.js
new file mode 100644
index 0000000000..ba69eeffc8
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Not-callable next value in a yield star position - number (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-not-callable-object-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-not-callable-object-throw.js
new file mode 100644
index 0000000000..7871989780
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Not-callable next value in a yield star position - object (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-not-callable-string-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-not-callable-string-throw.js
new file mode 100644
index 0000000000..14557c4e67
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Not-callable next value in a yield star position - string (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-not-callable-symbol-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-not-callable-symbol-throw.js
new file mode 100644
index 0000000000..2584c8a5a2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Not-callable next value in a yield star position - symbol (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-not-callable-undefined-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-not-callable-undefined-throw.js
new file mode 100644
index 0000000000..75fa4c5333
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Not-callable next value in a yield star position - undefined (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-then-get-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-then-get-abrupt.js
new file mode 100644
index 0000000000..f7cc2f3588
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Return abrupt after getting next().then (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-then-non-callable-boolean-fulfillpromise.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-then-non-callable-boolean-fulfillpromise.js
new file mode 100644
index 0000000000..9a486d6b4f
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: FulfillPromise if next().then is not-callable (boolean) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-then-non-callable-null-fulfillpromise.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-then-non-callable-null-fulfillpromise.js
new file mode 100644
index 0000000000..767625c782
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: FulfillPromise if next().then is not-callable (null) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-then-non-callable-number-fulfillpromise.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-then-non-callable-number-fulfillpromise.js
new file mode 100644
index 0000000000..2864b5a9b0
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: FulfillPromise if next().then is not-callable (number) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-then-non-callable-object-fulfillpromise.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-then-non-callable-object-fulfillpromise.js
new file mode 100644
index 0000000000..37271cc528
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: FulfillPromise if next().then is not-callable (object) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-then-non-callable-string-fulfillpromise.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-then-non-callable-string-fulfillpromise.js
new file mode 100644
index 0000000000..7863bf280a
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: FulfillPromise if next().then is not-callable (string) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-then-non-callable-symbol-fulfillpromise.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-then-non-callable-symbol-fulfillpromise.js
new file mode 100644
index 0000000000..639fc0c175
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: FulfillPromise if next().then is not-callable (symbol) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-then-non-callable-undefined-fulfillpromise.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-then-non-callable-undefined-fulfillpromise.js
new file mode 100644
index 0000000000..4c3469f468
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: FulfillPromise if next().then is not-callable (undefined) (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-next-then-returns-abrupt.js b/js/src/tests/test262/language/statements/async-generator/yield-star-next-then-returns-abrupt.js
new file mode 100644
index 0000000000..adc3d00793
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: Return abrupt after calling next().then (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, Symbol.asyncIterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-normal-notdone-iter-value-throws.js b/js/src/tests/test262/language/statements/async-generator/yield-star-normal-notdone-iter-value-throws.js
new file mode 100644
index 0000000000..4a4d8a4d30
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-star-normal-notdone-iter-value-throws.js
@@ -0,0 +1,54 @@
+// |reftest| async
+// Copyright (C) 2019 André Bargull. 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: >
+    Abrupt completion when calling IteratorValue is propagated when received.[[Type]] is normal.
+info: |
+    14.4.14 Runtime Semantics: Evaluation
+    YieldExpression : yield* AssignmentExpression
+
+    ...
+    7. Repeat,
+      a. If received.[[Type]] is normal, then
+        ...
+        vi. If generatorKind is async, then set received to AsyncGeneratorYield(? IteratorValue(innerResult)).
+        ...
+
+flags: [async]
+features: [async-iteration]
+---*/
+
+var token = {};
+
+var asyncIter = {
+  [Symbol.asyncIterator]() {
+      return this;
+  },
+  next() {
+    return {
+      done: false,
+      get value() {
+        throw token;
+      }
+    };
+  }
+};
+
+async function* f() {
+  var thrown;
+  try {
+    yield* asyncIter;
+  } catch (e) {
+    thrown = e;
+  }
+  return thrown;
+}
+
+var iter = f();
+
+iter.next().then(({value}) => {
+    assert.sameValue(value, token);
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-star-promise-not-unwrapped.js b/js/src/tests/test262/language/statements/async-generator/yield-star-promise-not-unwrapped.js
new file mode 100644
index 0000000000..4dabe6af43
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-star-promise-not-unwrapped.js
@@ -0,0 +1,42 @@
+// |reftest| async
+// Copyright (C) 2022 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-generator-function-definitions-runtime-semantics-evaluation
+description: >
+  `yield*` in an async generator does not await promises returned by a manually implemented async iterator.
+flags: [async]
+features: [async-iteration]
+---*/
+
+var innerPromise = Promise.resolve("unwrapped value");
+
+var asyncIter = {
+  [Symbol.asyncIterator]() {
+    return this;
+  },
+  next() {
+    return {
+      done: false,
+      value: innerPromise,
+    };
+  },
+  get return() {
+    throw new Test262Error(".return should not be accessed");
+  },
+  get throw() {
+    throw new Test262Error(".throw should not be accessed");
+  },
+};
+
+async function* f() {
+  yield* asyncIter;
+}
+
+f()
+  .next()
+  .then(v => {
+    assert.sameValue(v.value, innerPromise, "yield* should not unwrap promises from manually-implemented async iterators");
+  })
+  .then($DONE, $DONE)
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-star-return-missing-value-is-awaited.js b/js/src/tests/test262/language/statements/async-generator/yield-star-return-missing-value-is-awaited.js
new file mode 100644
index 0000000000..d4d3f641be
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-star-return-missing-value-is-awaited.js
@@ -0,0 +1,45 @@
+// |reftest| async
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-generator-function-definitions-runtime-semantics-evaluation
+description: >
+  If iterator's "return" method is missing,
+  received value is awaited before forwarded to the runtime.
+info: |
+  YieldExpression : yield * AssignmentExpression
+
+  [...]
+  7. Repeat,
+    [...]
+    c. Else,
+      i. Assert: received.[[Type]] is return.
+      ii. Let return be ? GetMethod(iterator, "return").
+      iii. If return is undefined, then
+        1. If generatorKind is async, then set received.[[Value]] to ? Await(received.[[Value]]).
+        2. Return Completion(received).
+features: [Symbol.asyncIterator, async-iteration]
+flags: [async]
+---*/
+
+var asyncIterable = {
+  [Symbol.asyncIterator]: function() {
+    return this;
+  },
+  next: function() {
+    return {value: 1, done: false};
+  },
+};
+
+async function* asyncGenerator() {
+  yield* asyncIterable;
+}
+
+var asyncIterator = asyncGenerator();
+asyncIterator.next().then(function() {
+  var promise = Promise.resolve(2).then(() => 3);
+  return asyncIterator.return(promise).then(function(result) {
+    assert.sameValue(result.value, 3);
+    assert.sameValue(result.done, true);
+  });
+}).then($DONE, $DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-star-return-notdone-iter-value-throws.js b/js/src/tests/test262/language/statements/async-generator/yield-star-return-notdone-iter-value-throws.js
new file mode 100644
index 0000000000..f0fbdabdd6
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-star-return-notdone-iter-value-throws.js
@@ -0,0 +1,64 @@
+// |reftest| async
+// Copyright (C) 2019 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-generator-function-definitions-runtime-semantics-evaluation
+description: >
+    Abrupt completion when calling IteratorValue is propagated when received.[[Type]] is return.
+info: |
+    14.4.14 Runtime Semantics: Evaluation
+    YieldExpression : yield* AssignmentExpression
+
+    ...
+    7. Repeat,
+      ...
+      c. Else,
+        i. Assert: received.[[Type]] is return.
+        ...
+        ix. If generatorKind is async, then set received to AsyncGeneratorYield(? IteratorValue(innerReturnResult)).
+        ...
+
+flags: [async]
+features: [async-iteration]
+---*/
+
+var token = {};
+
+var asyncIter = {
+  [Symbol.asyncIterator]() {
+      return this;
+  },
+  next() {
+    return {
+      done: false,
+      value: undefined,
+    };
+  },
+  return() {
+    return {
+      done: false,
+      get value() {
+        throw token;
+      }
+    };
+  }
+};
+
+async function* f() {
+  var thrown;
+  try {
+    yield* asyncIter;
+  } catch (e) {
+    thrown = e;
+  }
+  return thrown;
+}
+
+var iter = f();
+
+iter.next().then(() => {
+  iter.return().then(({value}) => {
+    assert.sameValue(value, token);
+  }).then($DONE, $DONE);
+}).catch($DONE);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-star-return-then-getter-ticks.js b/js/src/tests/test262/language/statements/async-generator/yield-star-return-then-getter-ticks.js
new file mode 100644
index 0000000000..efa97408a2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-star-return-then-getter-ticks.js
@@ -0,0 +1,145 @@
+// |reftest| async
+// Copyright (C) 2019 André Bargull. 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: >
+  Return resumption value is awaited upon and hence is treated as a thenable.
+info: |
+  15.5.5 Runtime Semantics: Evaluation
+    YieldExpression : yield* AssignmentExpression
+
+    ...
+    7. Repeat,
+      a. If received.[[Type]] is normal, then
+        i. Let innerResult be ? Call(iteratorRecord.[[NextMethod]], iteratorRecord.[[Iterator]],
+                                     « received.[[Value]] »).
+        ii. If generatorKind is async, then set innerResult to ? Await(innerResult).
+        ...
+        vi. If generatorKind is async, then set received to AsyncGeneratorYield(? IteratorValue(innerResult)).
+        ...
+      ...
+      c. Else,
+        i. Assert: received.[[Type]] is return.
+        ii. Let return be ? GetMethod(iterator, "return").
+        iii. If return is undefined, then
+          1. If generatorKind is async, then set received.[[Value]] to ? Await(received.[[Value]]).
+          2. Return Completion(received).
+        ...
+
+  27.6.3.8 AsyncGeneratorYield ( value )
+    ...
+    12. If queue is not empty, then
+      ...
+    13. Else,
+      ...
+      c. Set the code evaluation state of genContext such that when evaluation is resumed with a
+       Completion resumptionValue the following steps will be performed:
+        i. Return ? AsyncGeneratorUnwrapYieldResumption(resumptionValue).
+
+  27.6.3.7 AsyncGeneratorUnwrapYieldResumption ( resumptionValue  )
+    ...
+    2. Let awaited be Completion(Await(resumptionValue.[[Value]])).
+    ...
+
+  6.2.3.1 Await
+    ...
+    2. Let promise be ? PromiseResolve(%Promise%, « value »).
+    ...
+
+  27.2.4.7.1 PromiseResolve ( C, x )
+    ...
+    2. Let promiseCapability be ? NewPromiseCapability(C).
+    3. Perform ? Call(promiseCapability.[[Resolve]], undefined, « x »).
+    ...
+
+  27.2.1.5 NewPromiseCapability ( C )
+    ...
+    7. Let promise be ? Construct(C, « executor »).
+    ...
+
+  27.2.3.1 Promise ( executor )
+    ...
+    8. Let resolvingFunctions be CreateResolvingFunctions(promise).
+    ...
+
+  27.2.1.3 CreateResolvingFunctions ( promise )
+    ...
+    2. Let stepsResolve be the algorithm steps defined in Promise Resolve Functions (25.6.1.3.2).
+    3. Let resolve be CreateBuiltinFunction(stepsResolve, « [[Promise]], [[AlreadyResolved]] »).
+    ...
+
+  27.2.1.3.2 Promise Resolve Functions
+    ...
+    9. Let then be Get(resolution, "then").
+    ...
+
+includes: [compareArray.js]
+flags: [async]
+features: [async-iteration]
+---*/
+
+var expected = [
+  "start",
+
+  // `Await(innerResult)` promise resolved.
+  "tick 1",
+
+  // "then" of `resumptionValue.[[Value]]` accessed.
+  "get then",
+
+  // `Await(resumptionValue.[[Value]])` promise resolved.
+  "tick 2",
+
+  // Get iterator "return" method.
+  "get return",
+
+  // "then" of `received.[[Value]]` accessed.
+  "get then",
+
+  // `Await(received.[[Value]])` promise resolved.
+  "tick 3",
+];
+
+var actual = [];
+
+var asyncIter = {
+  [Symbol.asyncIterator]() {
+    return this;
+  },
+  next() {
+    return {
+      done: false,
+    };
+  },
+  get return() {
+    actual.push("get return");
+  }
+};
+
+async function* f() {
+  actual.push("start");
+  yield* asyncIter;
+  actual.push("stop - never reached");
+}
+
+Promise.resolve(0)
+  .then(() => actual.push("tick 1"))
+  .then(() => actual.push("tick 2"))
+  .then(() => actual.push("tick 3"))
+  .then(() => {
+    assert.compareArray(actual, expected, "Ticks for return with thenable getter");
+}).then($DONE, $DONE);
+
+var it = f();
+
+// Start generator execution.
+it.next();
+
+// Stop generator execution.
+it.return({
+  get then() {
+    actual.push("get then");
+  }
+});
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-star-sync-next.js b/js/src/tests/test262/language/statements/async-generator/yield-star-sync-next.js
new file mode 100644
index 0000000000..a0f99421a2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: execution order for yield* with sync iterator and next() (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-sync-return.js b/js/src/tests/test262/language/statements/async-generator/yield-star-sync-return.js
new file mode 100644
index 0000000000..ff28d86c36
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: execution order for yield* with sync iterator and return() (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration, Symbol.asyncIterator]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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/statements/async-generator/yield-star-sync-throw.js b/js/src/tests/test262/language/statements/async-generator/yield-star-sync-throw.js
new file mode 100644
index 0000000000..f656b36759
--- /dev/null
+++ b/js/src/tests/test262/language/statements/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-declaration.template
+/*---
+description: execution order for yield* with sync iterator and throw() (Async generator Function declaration)
+esid: prod-AsyncGeneratorDeclaration
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    Async Generator Function Definitions
+
+    AsyncGeneratorDeclaration:
+      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;
+
+async function *gen() {
+  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($DONE);
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-star-throw-notdone-iter-value-throws.js b/js/src/tests/test262/language/statements/async-generator/yield-star-throw-notdone-iter-value-throws.js
new file mode 100644
index 0000000000..fbb3376934
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-star-throw-notdone-iter-value-throws.js
@@ -0,0 +1,65 @@
+// |reftest| async
+// Copyright (C) 2019 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-generator-function-definitions-runtime-semantics-evaluation
+description: >
+    Abrupt completion when calling IteratorValue is propagated when received.[[Type]] is throw.
+info: |
+    14.4.14 Runtime Semantics: Evaluation
+    YieldExpression : yield* AssignmentExpression
+
+    ...
+    7. Repeat,
+      ...
+      b. Else if received.[[Type]] is throw, then
+        ...
+        ii. If throw is not undefined, then
+          ...
+          7. If generatorKind is async, then set received to AsyncGeneratorYield(? IteratorValue(innerResult)).
+          ...
+
+flags: [async]
+features: [async-iteration]
+---*/
+
+var token = {};
+
+var asyncIter = {
+  [Symbol.asyncIterator]() {
+      return this;
+  },
+  next() {
+    return {
+      done: false,
+      value: undefined,
+    };
+  },
+  throw() {
+    return {
+      done: false,
+      get value() {
+        throw token;
+      }
+    };
+  }
+};
+
+async function* f() {
+  var thrown;
+  try {
+    yield* asyncIter;
+  } catch (e) {
+    thrown = e;
+  }
+  return thrown;
+}
+
+var iter = f();
+
+iter.next().then(() => {
+  iter.throw().then(({value}) => {
+    assert.sameValue(value, token);
+  }).then($DONE, $DONE);
+}).catch($DONE);