Adding upstream version 86.0.1.upstream/86.0.1upstream

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

39 files changed, 2326 insertions, 0 deletions

diff --git a/js/src/tests/test262/language/expressions/class/gen-method/array-destructuring-param-strict-body.js b/js/src/tests/test262/language/expressions/class/gen-method/array-destructuring-param-strict-body.js
new file mode 100644
index 0000000000..382571774f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/array-destructuring-param-strict-body.js
@@ -0,0 +1,159 @@
+// |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/cls-expr-gen-meth.template
+/*---
+description: ArrayBindingPattern and Use Strict Directive are not allowed to coexist for the same function. (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [rest-parameters, generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    13.3.3.4 Static Semantics: IsSimpleParameterList
+
+    BindingElement : BindingPattern
+
+    1. Return false.
+
+    14.1.2 Static Semantics: Early Errors
+
+    FunctionDeclaration : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+    FunctionDeclaration : function ( FormalParameters ) { FunctionBody }
+    FunctionExpression : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.2.1 Static Semantics: Early Errors
+
+    ArrowFunction : ArrowParameters => ConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of ConciseBody is true and
+      IsSimpleParameterList of ArrowParameters is false.
+
+    14.3.1 Static Semantics: Early Errors
+
+    MethodDefinition : PropertyName ( UniqueFormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    MethodDefinition : set PropertyName ( PropertySetParameterList ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of PropertySetParameterList is false.
+
+    14.4.1 Static Semantics: Early Errors
+
+    GeneratorMethod : * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    GeneratorDeclaration : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+    GeneratorDeclaration : function * ( FormalParameters ) { GeneratorBody }
+    GeneratorExpression : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    14.5.1 Static Semantics: Early Errors
+
+    AsyncGeneratorMethod : async * PropertyName ( UniqueFormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncGeneratorDeclaration : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorDeclaration : async function * ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorExpression : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.7.1 Static Semantics: Early Errors
+
+    AsyncMethod : async PropertyName ( UniqueFormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncFunctionDeclaration : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionDeclaration : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.8.1 Static Semantics: Early Errors
+
+    AsyncArrowFunction : CoverCallExpressionAndAsyncArrowHead => AsyncConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncConciseBody is true and
+      IsSimpleParameterList of CoverCallExpressionAndAsyncArrowHead is false.
+
+---*/
+$DONOTEVALUATE();
+
+0, class {
+  *method([element]) {
+    "use strict";
+  }
+};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/browser.js b/js/src/tests/test262/language/expressions/class/gen-method/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/browser.js
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-abrupt.js b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-abrupt.js
new file mode 100644
index 0000000000..7ae11fb838
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-abrupt.js
@@ -0,0 +1,89 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-abrupt.case
+// - src/function-forms/error/cls-expr-gen-meth.template
+/*---
+description: Abrupt completion returned by evaluation of initializer (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [default-parameters, generators]
+flags: [generated]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+
+var callCount = 0;
+var C = class {
+  *method(_ = (function() { throw new Test262Error(); }())) {
+    
+    callCount = callCount + 1;
+  }
+};
+
+assert.throws(Test262Error, function() {
+  C.prototype.method();
+});
+assert.sameValue(callCount, 0, 'method body not evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-arg-val-not-undefined.js b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-arg-val-not-undefined.js
new file mode 100644
index 0000000000..671666e723
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-arg-val-not-undefined.js
@@ -0,0 +1,114 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-arg-val-not-undefined.case
+// - src/function-forms/default/cls-expr-gen-meth.template
+/*---
+description: Use of initializer when argument value is not `undefined` (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [default-parameters, generators]
+flags: [generated]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    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;
+var C = class {
+  *method(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;
+  }
+};
+
+C.prototype.method(false, '', NaN, 0, null, obj).next();
+
+// Stores a reference `ref` for case evaluation
+var ref = C.prototype.method;
+
+assert.sameValue(callCount, 1, 'method invoked exactly once');
+
+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');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-arg-val-undefined.js b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-arg-val-undefined.js
new file mode 100644
index 0000000000..601bc232b2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-arg-val-undefined.js
@@ -0,0 +1,97 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-arg-val-undefined.case
+// - src/function-forms/default/cls-expr-gen-meth.template
+/*---
+description: Use of initializer when argument value is `undefined` (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [default-parameters, generators]
+flags: [generated]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    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;
+var C = class {
+  *method(fromLiteral = 23, fromExpr = 45, fromHole = 99) {
+    assert.sameValue(fromLiteral, 23);
+    assert.sameValue(fromExpr, 45);
+    assert.sameValue(fromHole, 99);
+    callCount = callCount + 1;
+  }
+};
+
+C.prototype.method(undefined, void 0).next();
+
+// Stores a reference `ref` for case evaluation
+var ref = C.prototype.method;
+
+assert.sameValue(callCount, 1, 'method invoked exactly once');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-duplicates.js b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-duplicates.js
new file mode 100644
index 0000000000..4dfd12d4b2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-duplicates.js
@@ -0,0 +1,88 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-duplicates.case
+// - src/function-forms/syntax/cls-expr-gen-meth.template
+/*---
+description: It is a Syntax Error if BoundNames of FormalParameters contains any duplicate elements. (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [default-parameters, generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    14.1.2 Static Semantics: Early Errors
+
+    StrictFormalParameters : FormalParameters
+
+    - It is a Syntax Error if BoundNames of FormalParameters contains any
+      duplicate elements.
+
+    FormalParameters : FormalParameterList
+
+    - It is a Syntax Error if IsSimpleParameterList of FormalParameterList is
+      false and BoundNames of FormalParameterList contains any duplicate
+      elements.
+
+---*/
+$DONOTEVALUATE();
+
+0, class {
+  *method(x = 0, x) {
+    
+  }
+};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-ref-later.js b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-ref-later.js
new file mode 100644
index 0000000000..9bfbf71abc
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-ref-later.js
@@ -0,0 +1,90 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-ref-later.case
+// - src/function-forms/error/cls-expr-gen-meth.template
+/*---
+description: Referencing a parameter that occurs later in the ParameterList (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [default-parameters, generators]
+flags: [generated]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+var x = 0;
+
+var callCount = 0;
+var C = class {
+  *method(x = y, y) {
+    
+    callCount = callCount + 1;
+  }
+};
+
+assert.throws(ReferenceError, function() {
+  C.prototype.method();
+});
+assert.sameValue(callCount, 0, 'method body not evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-ref-prior.js b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-ref-prior.js
new file mode 100644
index 0000000000..69cca8620b
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-ref-prior.js
@@ -0,0 +1,94 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-ref-prior.case
+// - src/function-forms/default/cls-expr-gen-meth.template
+/*---
+description: Referencing a parameter that occurs earlier in the ParameterList (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [default-parameters, generators]
+flags: [generated]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+var x = 0;
+
+var callCount = 0;
+var C = class {
+  *method(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;
+  }
+};
+
+C.prototype.method(3).next();
+
+// Stores a reference `ref` for case evaluation
+var ref = C.prototype.method;
+
+assert.sameValue(callCount, 1, 'method invoked exactly once');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-ref-self.js b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-ref-self.js
new file mode 100644
index 0000000000..daa861f73d
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-ref-self.js
@@ -0,0 +1,90 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-ref-self.case
+// - src/function-forms/error/cls-expr-gen-meth.template
+/*---
+description: Referencing a parameter from within its own initializer (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [default-parameters, generators]
+flags: [generated]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments.
+
+---*/
+var x = 0;
+
+var callCount = 0;
+var C = class {
+  *method(x = x) {
+    
+    callCount = callCount + 1;
+  }
+};
+
+assert.throws(ReferenceError, function() {
+  C.prototype.method();
+});
+assert.sameValue(callCount, 0, 'method body not evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-rest.js b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-rest.js
new file mode 100644
index 0000000000..c5b333e3df
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-rest.js
@@ -0,0 +1,92 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-rest.case
+// - src/function-forms/syntax/cls-expr-gen-meth.template
+/*---
+description: RestParameter does not support an initializer (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [default-parameters, generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    14.1 Function Definitions
+
+    Syntax
+
+    FunctionRestParameter[Yield] :
+
+      BindingRestElement[?Yield]
+
+    13.3.3 Destructuring Binding Patterns
+
+    Syntax
+
+    BindingRestElement[Yield] :
+
+      ...BindingIdentifier[?Yield]
+      ...BindingPattern[?Yield]
+
+---*/
+$DONOTEVALUATE();
+
+0, class {
+  *method(...x = []) {
+    
+  }
+};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-trailing-comma.js b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-trailing-comma.js
new file mode 100644
index 0000000000..4c9c625f8e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/dflt-params-trailing-comma.js
@@ -0,0 +1,89 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-trailing-comma.case
+// - src/function-forms/default/cls-expr-gen-meth.template
+/*---
+description: A trailing comma should not increase the respective length, using default parameters (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [generators]
+flags: [generated]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] : FormalParameterList[?Yield, ?Await] ,
+---*/
+
+var callCount = 0;
+var C = class {
+  *method(a, b = 39,) {
+    assert.sameValue(a, 42);
+    assert.sameValue(b, 39);
+    callCount = callCount + 1;
+  }
+};
+
+C.prototype.method(42, undefined, 1).next();
+
+// Stores a reference `ref` for case evaluation
+var ref = C.prototype.method;
+
+assert.sameValue(callCount, 1, 'method invoked exactly once');
+
+assert.sameValue(ref.length, 1, 'length is properly set');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/browser.js b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/browser.js
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/cls-expr-gen-meth-forbidden-ext-direct-access-prop-arguments.js b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/cls-expr-gen-meth-forbidden-ext-direct-access-prop-arguments.js
new file mode 100644
index 0000000000..d760fdd8b4
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/cls-expr-gen-meth-forbidden-ext-direct-access-prop-arguments.js
@@ -0,0 +1,37 @@
+// 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/cls-expr-gen-meth.template
+/*---
+description: Forbidden extension, f.arguments (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [class, generators]
+flags: [generated, noStrict]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+
+    ECMAScript function objects defined using syntactic constructors in strict mode code must
+    not be created with own properties named "caller" or "arguments". Such own properties also
+    must not be created for function objects defined using an ArrowFunction, MethodDefinition,
+    GeneratorDeclaration, GeneratorExpression, AsyncGeneratorDeclaration, AsyncGeneratorExpression,
+    ClassDeclaration, ClassExpression, AsyncFunctionDeclaration, AsyncFunctionExpression, or
+    AsyncArrowFunction regardless of whether the definition is contained in strict mode code.
+    Built-in functions, strict functions created using the Function constructor, generator functions
+    created using the Generator constructor, async functions created using the AsyncFunction
+    constructor, and functions created using the bind method also must not be created with such own
+    properties.
+
+---*/
+
+var callCount = 0;
+var C = class {
+  *method() {
+    assert.sameValue(this.method.hasOwnProperty("arguments"), false);
+    callCount++;
+  }
+};
+
+C.prototype.method().next();
+assert.sameValue(callCount, 1, 'method body evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/cls-expr-gen-meth-forbidden-ext-direct-access-prop-caller.js b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/cls-expr-gen-meth-forbidden-ext-direct-access-prop-caller.js
new file mode 100644
index 0000000000..42381b9c8e
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/cls-expr-gen-meth-forbidden-ext-direct-access-prop-caller.js
@@ -0,0 +1,37 @@
+// 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/cls-expr-gen-meth.template
+/*---
+description: Forbidden extension, o.caller (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [class, generators]
+flags: [generated, noStrict]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+
+    ECMAScript function objects defined using syntactic constructors in strict mode code must
+    not be created with own properties named "caller" or "arguments". Such own properties also
+    must not be created for function objects defined using an ArrowFunction, MethodDefinition,
+    GeneratorDeclaration, GeneratorExpression, AsyncGeneratorDeclaration, AsyncGeneratorExpression,
+    ClassDeclaration, ClassExpression, AsyncFunctionDeclaration, AsyncFunctionExpression, or
+    AsyncArrowFunction regardless of whether the definition is contained in strict mode code.
+    Built-in functions, strict functions created using the Function constructor, generator functions
+    created using the Generator constructor, async functions created using the AsyncFunction
+    constructor, and functions created using the bind method also must not be created with such own
+    properties.
+
+---*/
+
+var callCount = 0;
+var C = class {
+  *method() {
+    assert.sameValue(this.method.hasOwnProperty("caller"), false);
+    callCount++;
+  }
+};
+
+C.prototype.method().next();
+assert.sameValue(callCount, 1, 'method body evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/shell.js b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b1/shell.js
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/browser.js b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/browser.js
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/cls-expr-gen-meth-forbidden-ext-indirect-access-own-prop-caller-get.js b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/cls-expr-gen-meth-forbidden-ext-indirect-access-own-prop-caller-get.js
new file mode 100644
index 0000000000..6f347e6def
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/cls-expr-gen-meth-forbidden-ext-indirect-access-own-prop-caller-get.js
@@ -0,0 +1,64 @@
+// 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/cls-expr-gen-meth.template
+/*---
+description: Forbidden extension, o.caller (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [class, generators]
+flags: [generated, noStrict]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+
+    If an implementation extends any function object with an own property named "caller" the value of
+    that property, as observed using [[Get]] or [[GetOwnProperty]], must not be a strict function
+    object. If it is an accessor property, the function that is the value of the property's [[Get]]
+    attribute must never return a strict function when called.
+
+---*/
+var CALLER_OWN_PROPERTY_DOES_NOT_EXIST = Symbol();
+function inner() {
+  // This property may exist, but is forbidden from having a value that is a strict function object
+  return inner.hasOwnProperty("caller")
+    ? inner.caller
+    : CALLER_OWN_PROPERTY_DOES_NOT_EXIST;
+}
+
+var callCount = 0;
+var C = class {
+  *method() {
+    /* implicit 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
+    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, this.method);
+    }
+
+    callCount++;
+  }
+};
+
+C.prototype.method().next();
+assert.sameValue(callCount, 1, 'method body evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/cls-expr-gen-meth-forbidden-ext-indirect-access-own-prop-caller-value.js b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/cls-expr-gen-meth-forbidden-ext-indirect-access-own-prop-caller-value.js
new file mode 100644
index 0000000000..b59a856eb6
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/cls-expr-gen-meth-forbidden-ext-indirect-access-own-prop-caller-value.js
@@ -0,0 +1,64 @@
+// 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/cls-expr-gen-meth.template
+/*---
+description: Forbidden extension, o.caller (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [class, generators]
+flags: [generated, noStrict]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+
+    If an implementation extends any function object with an own property named "caller" the value of
+    that property, as observed using [[Get]] or [[GetOwnProperty]], must not be a strict function
+    object. If it is an accessor property, the function that is the value of the property's [[Get]]
+    attribute must never return a strict function when called.
+
+---*/
+var CALLER_OWN_PROPERTY_DOES_NOT_EXIST = Symbol();
+function inner() {
+  // This property may exist, but is forbidden from having a value that is a strict function object
+  return inner.hasOwnProperty("caller")
+    ? inner.caller
+    : CALLER_OWN_PROPERTY_DOES_NOT_EXIST;
+}
+
+var callCount = 0;
+var C = class {
+  *method() {
+    /* implicit 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
+    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, this.method);
+    }
+
+    callCount++;
+  }
+};
+
+C.prototype.method().next();
+assert.sameValue(callCount, 1, 'method body evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/cls-expr-gen-meth-forbidden-ext-indirect-access-prop-caller.js b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/cls-expr-gen-meth-forbidden-ext-indirect-access-prop-caller.js
new file mode 100644
index 0000000000..94bd5da396
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/cls-expr-gen-meth-forbidden-ext-indirect-access-prop-caller.js
@@ -0,0 +1,64 @@
+// 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/cls-expr-gen-meth.template
+/*---
+description: Forbidden extension, o.caller (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [class, generators]
+flags: [generated, noStrict]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+
+    If an implementation extends any function object with an own property named "caller" the value of
+    that property, as observed using [[Get]] or [[GetOwnProperty]], must not be a strict function
+    object. If it is an accessor property, the function that is the value of the property's [[Get]]
+    attribute must never return a strict function when called.
+
+---*/
+var CALLER_OWN_PROPERTY_DOES_NOT_EXIST = Symbol();
+function inner() {
+  // This property may exist, but is forbidden from having a value that is a strict function object
+  return inner.hasOwnProperty("caller")
+    ? inner.caller
+    : CALLER_OWN_PROPERTY_DOES_NOT_EXIST;
+}
+
+var callCount = 0;
+var C = class {
+  *method() {
+    /* implicit 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
+    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, this.method);
+    }
+
+    callCount++;
+  }
+};
+
+C.prototype.method().next();
+assert.sameValue(callCount, 1, 'method body evaluated');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/shell.js b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/b2/shell.js
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/browser.js b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/browser.js
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/shell.js b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/forbidden-ext/shell.js
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/object-destructuring-param-strict-body.js b/js/src/tests/test262/language/expressions/class/gen-method/object-destructuring-param-strict-body.js
new file mode 100644
index 0000000000..0839174212
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/object-destructuring-param-strict-body.js
@@ -0,0 +1,159 @@
+// |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/cls-expr-gen-meth.template
+/*---
+description: ObjectBindingPattern and Use Strict Directive are not allowed to coexist for the same function. (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [rest-parameters, generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    13.3.3.4 Static Semantics: IsSimpleParameterList
+
+    BindingElement : BindingPattern
+
+    1. Return false.
+
+    14.1.2 Static Semantics: Early Errors
+
+    FunctionDeclaration : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+    FunctionDeclaration : function ( FormalParameters ) { FunctionBody }
+    FunctionExpression : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.2.1 Static Semantics: Early Errors
+
+    ArrowFunction : ArrowParameters => ConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of ConciseBody is true and
+      IsSimpleParameterList of ArrowParameters is false.
+
+    14.3.1 Static Semantics: Early Errors
+
+    MethodDefinition : PropertyName ( UniqueFormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    MethodDefinition : set PropertyName ( PropertySetParameterList ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of PropertySetParameterList is false.
+
+    14.4.1 Static Semantics: Early Errors
+
+    GeneratorMethod : * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    GeneratorDeclaration : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+    GeneratorDeclaration : function * ( FormalParameters ) { GeneratorBody }
+    GeneratorExpression : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    14.5.1 Static Semantics: Early Errors
+
+    AsyncGeneratorMethod : async * PropertyName ( UniqueFormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncGeneratorDeclaration : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorDeclaration : async function * ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorExpression : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.7.1 Static Semantics: Early Errors
+
+    AsyncMethod : async PropertyName ( UniqueFormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncFunctionDeclaration : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionDeclaration : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.8.1 Static Semantics: Early Errors
+
+    AsyncArrowFunction : CoverCallExpressionAndAsyncArrowHead => AsyncConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncConciseBody is true and
+      IsSimpleParameterList of CoverCallExpressionAndAsyncArrowHead is false.
+
+---*/
+$DONOTEVALUATE();
+
+0, class {
+  *method({property}) {
+    "use strict";
+  }
+};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/params-trailing-comma-multiple.js b/js/src/tests/test262/language/expressions/class/gen-method/params-trailing-comma-multiple.js
new file mode 100644
index 0000000000..c204e8597f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/params-trailing-comma-multiple.js
@@ -0,0 +1,89 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/params-trailing-comma-multiple.case
+// - src/function-forms/default/cls-expr-gen-meth.template
+/*---
+description: A trailing comma should not increase the respective length, using multiple parameters (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [generators]
+flags: [generated]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] : FormalParameterList[?Yield, ?Await] ,
+---*/
+
+var callCount = 0;
+var C = class {
+  *method(a, b,) {
+    assert.sameValue(a, 42);
+    assert.sameValue(b, 39);
+    callCount = callCount + 1;
+  }
+};
+
+C.prototype.method(42, 39, 1).next();
+
+// Stores a reference `ref` for case evaluation
+var ref = C.prototype.method;
+
+assert.sameValue(callCount, 1, 'method invoked exactly once');
+
+assert.sameValue(ref.length, 2, 'length is properly set');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/params-trailing-comma-single.js b/js/src/tests/test262/language/expressions/class/gen-method/params-trailing-comma-single.js
new file mode 100644
index 0000000000..3bd2c86926
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/params-trailing-comma-single.js
@@ -0,0 +1,88 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/params-trailing-comma-single.case
+// - src/function-forms/default/cls-expr-gen-meth.template
+/*---
+description: A trailing comma should not increase the respective length, using a single parameter (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [generators]
+flags: [generated]
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] : FormalParameterList[?Yield, ?Await] ,
+---*/
+
+var callCount = 0;
+var C = class {
+  *method(a,) {
+    assert.sameValue(a, 42);
+    callCount = callCount + 1;
+  }
+};
+
+C.prototype.method(42, 39).next();
+
+// Stores a reference `ref` for case evaluation
+var ref = C.prototype.method;
+
+assert.sameValue(callCount, 1, 'method invoked exactly once');
+
+assert.sameValue(ref.length, 1, 'length is properly set');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/rest-param-strict-body.js b/js/src/tests/test262/language/expressions/class/gen-method/rest-param-strict-body.js
new file mode 100644
index 0000000000..969ed39077
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/rest-param-strict-body.js
@@ -0,0 +1,159 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/rest-param-strict-body.case
+// - src/function-forms/syntax/cls-expr-gen-meth.template
+/*---
+description: RestParameter and Use Strict Directive are not allowed to coexist for the same function. (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [rest-parameters, generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    14.1.13 Static Semantics: IsSimpleParameterList
+
+    FormalParameters : FormalParameterList , FunctionRestParameter
+
+    1. Return false.
+
+    14.1.2 Static Semantics: Early Errors
+
+    FunctionDeclaration : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+    FunctionDeclaration : function ( FormalParameters ) { FunctionBody }
+    FunctionExpression : function BindingIdentifier ( FormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.2.1 Static Semantics: Early Errors
+
+    ArrowFunction : ArrowParameters => ConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of ConciseBody is true and
+      IsSimpleParameterList of ArrowParameters is false.
+
+    14.3.1 Static Semantics: Early Errors
+
+    MethodDefinition : PropertyName ( UniqueFormalParameters ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    MethodDefinition : set PropertyName ( PropertySetParameterList ) { FunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
+      IsSimpleParameterList of PropertySetParameterList is false.
+
+    14.4.1 Static Semantics: Early Errors
+
+    GeneratorMethod : * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    GeneratorDeclaration : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+    GeneratorDeclaration : function * ( FormalParameters ) { GeneratorBody }
+    GeneratorExpression : function * BindingIdentifier ( FormalParameters ) { GeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of GeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    14.5.1 Static Semantics: Early Errors
+
+    AsyncGeneratorMethod : async * PropertyName ( UniqueFormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncGeneratorDeclaration : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorDeclaration : async function * ( FormalParameters ) { AsyncGeneratorBody }
+    AsyncGeneratorExpression : async function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncGeneratorBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.7.1 Static Semantics: Early Errors
+
+    AsyncMethod : async PropertyName ( UniqueFormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of UniqueFormalParameters is false.
+
+    AsyncFunctionDeclaration : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionDeclaration : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function ( FormalParameters ) { AsyncFunctionBody }
+    AsyncFunctionExpression : async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncFunctionBody is true and
+      IsSimpleParameterList of FormalParameters is false.
+
+    14.8.1 Static Semantics: Early Errors
+
+    AsyncArrowFunction : CoverCallExpressionAndAsyncArrowHead => AsyncConciseBody
+
+    - It is a Syntax Error if ContainsUseStrict of AsyncConciseBody is true and
+      IsSimpleParameterList of CoverCallExpressionAndAsyncArrowHead is false.
+
+---*/
+$DONOTEVALUATE();
+
+0, class {
+  *method(a,...rest) {
+    "use strict";
+  }
+};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/rest-params-trailing-comma-early-error.js b/js/src/tests/test262/language/expressions/class/gen-method/rest-params-trailing-comma-early-error.js
new file mode 100644
index 0000000000..90fed21dfe
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/rest-params-trailing-comma-early-error.js
@@ -0,0 +1,85 @@
+// |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/cls-expr-gen-meth.template
+/*---
+description: It's a syntax error if a FunctionRestParameter is followed by a trailing comma (class expression method)
+esid: sec-class-definitions-runtime-semantics-evaluation
+features: [generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassExpression : class BindingIdentifieropt ClassTail
+
+    1. If BindingIdentifieropt is not present, let className be undefined.
+    2. Else, let className be StringValue of BindingIdentifier.
+    3. Let value be the result of ClassDefinitionEvaluation of ClassTail
+       with argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.4.13 Runtime Semantics: PropertyDefinitionEvaluation
+
+    GeneratorMethod :
+        * PropertyName ( StrictFormalParameters ) { GeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this GeneratorMethod is strict mode code,
+       let strict be true. Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be GeneratorFunctionCreate(Method,
+       StrictFormalParameters, GeneratorBody, scope, strict).
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] :
+        [empty]
+        FunctionRestParameter[?Yield, ?Await]
+        FormalParameterList[?Yield, ?Await]
+        FormalParameterList[?Yield, ?Await] ,
+        FormalParameterList[?Yield, ?Await] , FunctionRestParameter[?Yield, ?Await]
+---*/
+$DONOTEVALUATE();
+
+0, class {
+  *method(...a,) {
+    
+  }
+};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/shell.js b/js/src/tests/test262/language/expressions/class/gen-method/shell.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/shell.js
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/yield-as-binding-identifier-escaped.js b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-binding-identifier-escaped.js
new file mode 100644
index 0000000000..b23ff6b26a
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-binding-identifier-escaped.js
@@ -0,0 +1,36 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/generators/yield-as-binding-identifier-escaped.case
+// - src/generators/syntax/class-expr-method.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Generator method as a ClassExpression element)
+esid: prod-GeneratorMethod
+features: [generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassElement :
+      MethodDefinition
+
+    MethodDefinition :
+      GeneratorMethod
+
+    14.4 Generator Function Definitions
+
+    GeneratorMethod :
+      * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+var C = class {*gen() {
+    var yi\u0065ld;
+}};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/yield-as-binding-identifier.js b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-binding-identifier.js
new file mode 100644
index 0000000000..1c1f7fb97f
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-binding-identifier.js
@@ -0,0 +1,36 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/generators/yield-as-binding-identifier.case
+// - src/generators/syntax/class-expr-method.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a binding identifier. (Generator method as a ClassExpression element)
+esid: prod-GeneratorMethod
+features: [generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassElement :
+      MethodDefinition
+
+    MethodDefinition :
+      GeneratorMethod
+
+    14.4 Generator Function Definitions
+
+    GeneratorMethod :
+      * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+
+    BindingIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+var C = class {*gen() {
+    var yield;
+}};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/yield-as-identifier-reference-escaped.js b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-identifier-reference-escaped.js
new file mode 100644
index 0000000000..a300a44742
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-identifier-reference-escaped.js
@@ -0,0 +1,36 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/generators/yield-as-identifier-reference-escaped.case
+// - src/generators/syntax/class-expr-method.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Generator method as a ClassExpression element)
+esid: prod-GeneratorMethod
+features: [generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassElement :
+      MethodDefinition
+
+    MethodDefinition :
+      GeneratorMethod
+
+    14.4 Generator Function Definitions
+
+    GeneratorMethod :
+      * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+var C = class {*gen() {
+    void yi\u0065ld;
+}};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/yield-as-identifier-reference.js b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-identifier-reference.js
new file mode 100644
index 0000000000..117f7ac3a5
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-identifier-reference.js
@@ -0,0 +1,36 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/generators/yield-as-identifier-reference.case
+// - src/generators/syntax/class-expr-method.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as an identifier reference. (Generator method as a ClassExpression element)
+esid: prod-GeneratorMethod
+features: [generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassElement :
+      MethodDefinition
+
+    MethodDefinition :
+      GeneratorMethod
+
+    14.4 Generator Function Definitions
+
+    GeneratorMethod :
+      * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+
+    IdentifierReference : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+var C = class {*gen() {
+    void yield;
+}};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/yield-as-label-identifier-escaped.js b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-label-identifier-escaped.js
new file mode 100644
index 0000000000..8ec9ddf683
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-label-identifier-escaped.js
@@ -0,0 +1,36 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/generators/yield-as-label-identifier-escaped.case
+// - src/generators/syntax/class-expr-method.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a label identifier. (Generator method as a ClassExpression element)
+esid: prod-GeneratorMethod
+features: [generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassElement :
+      MethodDefinition
+
+    MethodDefinition :
+      GeneratorMethod
+
+    14.4 Generator Function Definitions
+
+    GeneratorMethod :
+      * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+var C = class {*gen() {
+    yi\u0065ld: ;
+}};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/yield-as-label-identifier.js b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-label-identifier.js
new file mode 100644
index 0000000000..aeb8c22d37
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/yield-as-label-identifier.js
@@ -0,0 +1,36 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/generators/yield-as-label-identifier.case
+// - src/generators/syntax/class-expr-method.template
+/*---
+description: yield is a reserved keyword within generator function bodies and may not be used as a label identifier. (Generator method as a ClassExpression element)
+esid: prod-GeneratorMethod
+features: [generators]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassElement :
+      MethodDefinition
+
+    MethodDefinition :
+      GeneratorMethod
+
+    14.4 Generator Function Definitions
+
+    GeneratorMethod :
+      * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+
+    LabelIdentifier : Identifier
+
+    It is a Syntax Error if this production has a [Yield] parameter and
+    StringValue of Identifier is "yield".
+
+---*/
+$DONOTEVALUATE();
+
+var C = class {*gen() {
+    yield: ;
+}};
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/yield-identifier-spread-strict-strict.js b/js/src/tests/test262/language/expressions/class/gen-method/yield-identifier-spread-strict-strict.js
new file mode 100644
index 0000000000..d726b13afa
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/yield-identifier-spread-strict-strict.js
@@ -0,0 +1,54 @@
+// |reftest| error:SyntaxError
+'use strict';
+// This file was procedurally generated from the following sources:
+// - src/generators/yield-identifier-spread-strict.case
+// - src/generators/default/class-expr-method.template
+/*---
+description: It's an early error if the AssignmentExpression is a function body with yield as an identifier in strict mode. (Generator method as a ClassExpression element)
+esid: prod-GeneratorMethod
+features: [object-spread, generators]
+flags: [generated, onlyStrict]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassElement :
+      MethodDefinition
+
+    MethodDefinition :
+      GeneratorMethod
+
+    14.4 Generator Function Definitions
+
+    GeneratorMethod :
+      * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+
+    Spread Properties
+
+    PropertyDefinition[Yield]:
+      (...)
+      ...AssignmentExpression[In, ?Yield]
+
+---*/
+$DONOTEVALUATE();
+
+var callCount = 0;
+
+var C = class {*gen() {
+    callCount += 1;
+    return {
+         ...(function() {
+            var yield;
+            throw new Test262Error();
+         }()),
+      }
+}}
+
+var gen = C.prototype.gen;
+
+var iter = gen();
+
+
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/yield-identifier-strict-strict.js b/js/src/tests/test262/language/expressions/class/gen-method/yield-identifier-strict-strict.js
new file mode 100644
index 0000000000..577563a951
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/yield-identifier-strict-strict.js
@@ -0,0 +1,45 @@
+// |reftest| error:SyntaxError
+'use strict';
+// This file was procedurally generated from the following sources:
+// - src/generators/yield-identifier-strict.case
+// - src/generators/default/class-expr-method.template
+/*---
+description: It's an early error if the generator body has another function body with yield as an identifier in strict mode. (Generator method as a ClassExpression element)
+esid: prod-GeneratorMethod
+features: [generators]
+flags: [generated, onlyStrict]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    ClassElement :
+      MethodDefinition
+
+    MethodDefinition :
+      GeneratorMethod
+
+    14.4 Generator Function Definitions
+
+    GeneratorMethod :
+      * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+---*/
+$DONOTEVALUATE();
+
+var callCount = 0;
+
+var C = class {*gen() {
+    callCount += 1;
+    (function() {
+        var yield;
+        throw new Test262Error();
+      }())
+}}
+
+var gen = C.prototype.gen;
+
+var iter = gen();
+
+
+
+assert.sameValue(callCount, 1);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/yield-spread-arr-multiple.js b/js/src/tests/test262/language/expressions/class/gen-method/yield-spread-arr-multiple.js
new file mode 100644
index 0000000000..d1ee8b09e0
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/yield-spread-arr-multiple.js
@@ -0,0 +1,52 @@
+// This file was procedurally generated from the following sources:
+// - src/generators/yield-spread-arr-multiple.case
+// - src/generators/default/class-expr-method.template
+/*---
+description: Use yield value in a array spread position (Generator method as a ClassExpression element)
+esid: prod-GeneratorMethod
+features: [generators]
+flags: [generated]
+includes: [compareArray.js]
+info: |
+    ClassElement :
+      MethodDefinition
+
+    MethodDefinition :
+      GeneratorMethod
+
+    14.4 Generator Function Definitions
+
+    GeneratorMethod :
+      * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+
+    Array Initializer
+
+    SpreadElement[Yield, Await]:
+      ...AssignmentExpression[+In, ?Yield, ?Await]
+
+---*/
+var arr = ['a', 'b', 'c'];
+var item;
+
+var callCount = 0;
+
+var C = class {*gen() {
+    callCount += 1;
+    yield [...yield yield];
+}}
+
+var gen = C.prototype.gen;
+
+var iter = gen();
+
+iter.next(false);
+item = iter.next(['a', 'b', 'c']);
+item = iter.next(item.value);
+
+assert(compareArray(item.value, arr));
+assert.sameValue(item.done, false);
+
+assert.sameValue(callCount, 1);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/yield-spread-arr-single.js b/js/src/tests/test262/language/expressions/class/gen-method/yield-spread-arr-single.js
new file mode 100644
index 0000000000..3a34a9245c
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/yield-spread-arr-single.js
@@ -0,0 +1,54 @@
+// This file was procedurally generated from the following sources:
+// - src/generators/yield-spread-arr-single.case
+// - src/generators/default/class-expr-method.template
+/*---
+description: Use yield value in a array spread position (Generator method as a ClassExpression element)
+esid: prod-GeneratorMethod
+features: [generators]
+flags: [generated]
+info: |
+    ClassElement :
+      MethodDefinition
+
+    MethodDefinition :
+      GeneratorMethod
+
+    14.4 Generator Function Definitions
+
+    GeneratorMethod :
+      * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+
+    Array Initializer
+
+    SpreadElement[Yield, Await]:
+      ...AssignmentExpression[+In, ?Yield, ?Await]
+---*/
+var arr = ['a', 'b', 'c'];
+
+var callCount = 0;
+
+var C = class {*gen() {
+    callCount += 1;
+    yield [...yield];
+}}
+
+var gen = C.prototype.gen;
+
+var iter = gen();
+
+iter.next(false);
+var item = iter.next(arr);
+var value = item.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(item.done, false);
+
+assert.sameValue(callCount, 1);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/language/expressions/class/gen-method/yield-spread-obj.js b/js/src/tests/test262/language/expressions/class/gen-method/yield-spread-obj.js
new file mode 100644
index 0000000000..930e769b68
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/class/gen-method/yield-spread-obj.js
@@ -0,0 +1,57 @@
+// This file was procedurally generated from the following sources:
+// - src/generators/yield-spread-obj.case
+// - src/generators/default/class-expr-method.template
+/*---
+description: Use yield value in a object spread position (Generator method as a ClassExpression element)
+esid: prod-GeneratorMethod
+features: [object-spread, generators]
+flags: [generated]
+info: |
+    ClassElement :
+      MethodDefinition
+
+    MethodDefinition :
+      GeneratorMethod
+
+    14.4 Generator Function Definitions
+
+    GeneratorMethod :
+      * PropertyName ( UniqueFormalParameters ) { GeneratorBody }
+
+
+    Spread Properties
+
+    PropertyDefinition[Yield]:
+      (...)
+      ...AssignmentExpression[In, ?Yield]
+
+---*/
+
+var callCount = 0;
+
+var C = class {*gen() {
+    callCount += 1;
+    yield {
+        ...yield,
+        y: 1,
+        ...yield yield,
+      };
+}}
+
+var gen = C.prototype.gen;
+
+var iter = gen();
+
+iter.next();
+iter.next({ x: 42 });
+iter.next({ x: 'lol' });
+var item = iter.next({ y: 39 });
+
+assert.sameValue(item.value.x, 42);
+assert.sameValue(item.value.y, 39);
+assert.sameValue(Object.keys(item.value).length, 2);
+assert.sameValue(item.done, false);
+
+assert.sameValue(callCount, 1);
+
+reportCompare(0, 0);