Generate tests

test/language/expressions/async-generator/dstr-ary-init-iter-close.js

@@ -0,0 +1,53 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-close.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Iterator is closed when not exhausted by pattern evaluation (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: false };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([x]) {
+  assert.sameValue(doneCallCount, 1);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-init-iter-no-close.js

@@ -0,0 +1,53 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-no-close.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Iterator is not closed when exhausted by pattern evaluation (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: true };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([x]) {
+  assert.sameValue(doneCallCount, 0);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-name-iter-val.js

@@ -0,0 +1,52 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-name-iter-val.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding with normal value iteration (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x, y, z]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-ary-elem-init.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([[x, y, z] = [4, 5, 6]]) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-ary-elem-iter.js

@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-iter.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([[x, y, z] = [4, 5, 6]]) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, 8);
+  assert.sameValue(z, 9);
+  callCount = callCount + 1;
+};
+
+f([[7, 8, 9]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-ary-elision-init.js

@@ -0,0 +1,51 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([[,] = g()]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-ary-elision-iter.js

@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-iter.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var callCount = 0;
+function* g() {
+  callCount += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([[,] = g()]) {
+  assert.sameValue(callCount, 0);
+  callCount = callCount + 1;
+};
+
+f([[]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-ary-empty-init.js

@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var initCount = 0;
+var iterCount = 0;
+var iter = function*() { iterCount += 1; }();
+
+
+var callCount = 0;
+var f;
+f = async function*([[] = function() { initCount += 1; return iter; }()]) {
+  assert.sameValue(initCount, 1);
+  assert.sameValue(iterCount, 0);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-ary-empty-iter.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-iter.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*([[] = function() { initCount += 1; }()]) {
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f([[23]]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-ary-rest-init.js

@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([[...x] = values]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-ary-rest-iter.js

@@ -0,0 +1,51 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-iter.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*([[...x] = function() { initCount += 1; }()]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f([values]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-init-exhausted.js

@@ -0,0 +1,43 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Destructuring initializer with an exhausted iterator (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23]) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-init-fn-name-arrow.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding does assign name to arrow functions (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([arrow = () => {}]) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-init-fn-name-class.js

@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-class.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([cls = class {}, xCls = class X {}, xCls2 = class { static name() {} }]) {
+  assert.sameValue(cls.name, 'cls');
+  assert.notSameValue(xCls.name, 'xCls');
+  assert.notSameValue(xCls2.name, 'xCls2');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-init-fn-name-cover.js

@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-cover.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding does assign name to "anonymous" functions "through" cover grammar (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([cover = (function () {}), xCover = (0, function() {})]) {
+  assert.sameValue(cover.name, 'cover');
+  assert.notSameValue(xCover.name, 'xCover');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-init-fn-name-fn.js

@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([fn = function () {}, xFn = function x() {}]) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-init-fn-name-gen.js

@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([gen = function* () {}, xGen = function* x() {}]) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-init-hole.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-hole.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Destructuring initializer with a "hole" (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    SingleNameBinding : BindingIdentifier Initializeropt
+    [...] 6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v). 8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23]) {
+  assert.sameValue(x, 23);
+  // another statement
+  callCount = callCount + 1;
+};
+
+f([,]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-init-skipped.js

@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*([w = counter(), x = counter(), y = counter(), z = counter()]) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f([null, 0, false, '']).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-init-undef.js

@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-undef.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Destructuring initializer with an undefined value (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23]) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f([undefined]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-iter-complete.js

@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-complete.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding when value iteration completes (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x]) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-iter-done.js

@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-done.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([_, x]) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-id-iter-val.js

@@ -0,0 +1,52 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x, y, z]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-obj-id-init.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ x, y, z } = { x: 44, y: 55, z: 66 }]) {
+  assert.sameValue(x, 44);
+  assert.sameValue(y, 55);
+  assert.sameValue(z, 66);
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-obj-id.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ x, y, z } = { x: 44, y: 55, z: 66 }]) {
+  assert.sameValue(x, 11);
+  assert.sameValue(y, 22);
+  assert.sameValue(z, 33);
+  callCount = callCount + 1;
+};
+
+f([{ x: 11, y: 22, z: 33 }]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-obj-prop-id-init.js

@@ -0,0 +1,54 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id-init.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }]) {
+  assert.sameValue(v, 444);
+  assert.sameValue(x, 555);
+  assert.sameValue(z, 666);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elem-obj-prop-id.js

@@ -0,0 +1,54 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }]) {
+  assert.sameValue(v, 777);
+  assert.sameValue(x, 888);
+  assert.sameValue(z, 999);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f([{ u: 777, w: 888, y: 999 }]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elision-exhausted.js

@@ -0,0 +1,49 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Elision accepts exhausted iterator (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+    2. Return NormalCompletion(empty).
+
+---*/
+var iter = function*() {}();
+iter.next();
+
+
+var callCount = 0;
+var f;
+f = async function*([,]) {
+  
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-elision.js

@@ -0,0 +1,58 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Elision advances iterator (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([,]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f(g()).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-empty.js

@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: No iteration occurs for an "empty" array binding pattern (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function*([]) {
+  assert.sameValue(iterations, 0);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-ary-elem.js

@@ -0,0 +1,65 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elem.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing an array BindingElementList pattern (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...[x, y, z]]) {
+  assert.sameValue(x, 3);
+  assert.sameValue(y, 4);
+  assert.sameValue(z, 5);
+  callCount = callCount + 1;
+};
+
+f([3, 4, 5]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-ary-elision.js

@@ -0,0 +1,71 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elision.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing an elision (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([...[,]]) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 1);
+  callCount = callCount + 1;
+};
+
+f(g()).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-ary-empty.js

@@ -0,0 +1,54 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-empty.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing an "empty" array pattern (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function*([...[]]) {
+  assert.sameValue(iterations, 1);
+  callCount = callCount + 1;
+};
+
+f(iter).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-ary-rest.js

@@ -0,0 +1,50 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-rest.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing a rest element (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([...[...x]]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+
+  callCount = callCount + 1;
+};
+
+f(values).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-id-elision.js

@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-elision.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element following elision elements (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    ArrayBindingPattern : [ Elisionopt BindingRestElement ]
+    1. If Elision is present, then
+       a. Let status be the result of performing
+          IteratorDestructuringAssignmentEvaluation of Elision with
+          iteratorRecord as the argument.
+       b. ReturnIfAbrupt(status).
+    2. Return the result of performing IteratorBindingInitialization for
+       BindingRestElement with iteratorRecord and environment as arguments.
+---*/
+var values = [1, 2, 3, 4, 5];
+
+
+var callCount = 0;
+var f;
+f = async function*([ , , ...x]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 3);
+  assert.sameValue(x[1], 4);
+  assert.sameValue(x[2], 5);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f(values).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-id-exhausted.js

@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: RestElement applied to an exhausted iterator (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. If environment is undefined, return PutValue(lhs, A).
+          ii. Return InitializeReferencedBinding(lhs, A).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([, , ...x]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 0);
+  callCount = callCount + 1;
+};
+
+f([1, 2]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-id.js

@@ -0,0 +1,43 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Lone rest element (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    [...] 3. Let A be ArrayCreate(0). [...] 5. Repeat
+       [...]
+       f. Let status be CreateDataProperty(A, ToString (n), nextValue).
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([...x]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f(values).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-init-ary.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-ary.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Reset element (nested array pattern) does not support initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...[ x ] = []]) {
+  
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-init-id.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Reset element (identifier) does not support initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...x = []]) {
+  
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-init-obj.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-obj.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Reset element (nested object pattern) does not support initializer (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ x } = []]) {
+  
+  callCount = callCount + 1;
+};
+
+f([]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-not-final-ary.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-ary.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element (array binding pattern) may not be followed by any element (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...[x], y]) {
+  
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-not-final-id.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element (identifier) may not be followed by any element (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...x, y]) {
+  
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-not-final-obj.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-obj.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element (object binding pattern) may not be followed by any element (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ x }, y]) {
+  
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-obj-id.js

@@ -0,0 +1,43 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing an object binding pattern (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ length }]) {
+  assert.sameValue(length, 3);
+  callCount = callCount + 1;
+};
+
+f([1, 2, 3]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-ary-ptrn-rest-obj-prop-id.js

@@ -0,0 +1,51 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-expr.template
+/*---
+description: Rest element containing an object binding pattern (async generator function expression)
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ 0: v, 1: w, 2: x, 3: y, length: z }]) {
+  assert.sameValue(v, 7);
+  assert.sameValue(w, 8);
+  assert.sameValue(x, 9);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, 3);
+
+  assert.throws(ReferenceError, function() {
+    length;
+  });
+  callCount = callCount + 1;
+};
+
+f([7, 8, 9]).next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-init-iter-close.js

@@ -0,0 +1,53 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-close.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Iterator is closed when not exhausted by pattern evaluation (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: false };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([x] = iter) {
+  assert.sameValue(doneCallCount, 1);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-init-iter-no-close.js

@@ -0,0 +1,53 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-init-iter-no-close.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Iterator is not closed when exhausted by pattern evaluation (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.5 Runtime Semantics: BindingInitialization
+
+    BindingPattern : ArrayBindingPattern
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, return ? IteratorClose(iterator,
+       result).
+    [...]
+
+---*/
+var doneCallCount = 0;
+var iter = {};
+iter[Symbol.iterator] = function() {
+  return {
+    next: function() {
+      return { value: null, done: true };
+    },
+    return: function() {
+      doneCallCount += 1;
+      return {};
+    }
+  };
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([x] = iter) {
+  assert.sameValue(doneCallCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-name-iter-val.js

@@ -0,0 +1,52 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-name-iter-val.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding with normal value iteration (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x, y, z] = [1, 2, 3]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-ary-elem-init.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([[x, y, z] = [4, 5, 6]] = []) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-ary-elem-iter.js

@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elem-iter.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([[x, y, z] = [4, 5, 6]] = [[7, 8, 9]]) {
+  assert.sameValue(x, 7);
+  assert.sameValue(y, 8);
+  assert.sameValue(z, 9);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-ary-elision-init.js

@@ -0,0 +1,51 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([[,] = g()] = []) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-ary-elision-iter.js

@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-elision-iter.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+
+---*/
+var callCount = 0;
+function* g() {
+  callCount += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([[,] = g()] = [[]]) {
+  assert.sameValue(callCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-ary-empty-init.js

@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var initCount = 0;
+var iterCount = 0;
+var iter = function*() { iterCount += 1; }();
+
+
+var callCount = 0;
+var f;
+f = async function*([[] = function() { initCount += 1; return iter; }()] = []) {
+  assert.sameValue(initCount, 1);
+  assert.sameValue(iterCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-ary-empty-iter.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-empty-iter.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*([[] = function() { initCount += 1; }()] = [[23]]) {
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-ary-rest-init.js

@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([[...x] = values] = []) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-ary-rest-iter.js

@@ -0,0 +1,51 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-ary-rest-iter.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with array binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       [...]
+       e. Else,
+          i. Let v be IteratorValue(next).
+          [...]
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+var values = [2, 1, 3];
+var initCount = 0;
+
+
+var callCount = 0;
+var f;
+f = async function*([[...x] = function() { initCount += 1; }()] = [values]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x[0], 2);
+  assert.sameValue(x[1], 1);
+  assert.sameValue(x[2], 3);
+  assert.sameValue(x.length, 3);
+  assert.notSameValue(x, values);
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-init-exhausted.js

@@ -0,0 +1,43 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer with an exhausted iterator (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23] = []) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-init-fn-name-arrow.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding does assign name to arrow functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([arrow = () => {}] = []) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-init-fn-name-class.js

@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-class.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([cls = class {}, xCls = class X {}, xCls2 = class { static name() {} }] = []) {
+  assert.sameValue(cls.name, 'cls');
+  assert.notSameValue(xCls.name, 'xCls');
+  assert.notSameValue(xCls2.name, 'xCls2');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-init-fn-name-cover.js

@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-cover.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding does assign name to "anonymous" functions "through" cover grammar (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([cover = (function () {}), xCover = (0, function() {})] = []) {
+  assert.sameValue(cover.name, 'cover');
+  assert.notSameValue(xCover.name, 'xCover');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-init-fn-name-fn.js

@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([fn = function () {}, xFn = function x() {}] = []) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-init-fn-name-gen.js

@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([gen = function* () {}, xGen = function* x() {}] = []) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-init-hole.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-hole.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer with a "hole" (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    SingleNameBinding : BindingIdentifier Initializeropt
+    [...] 6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v). 8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23] = [,]) {
+  assert.sameValue(x, 23);
+  // another statement
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-init-skipped.js

@@ -0,0 +1,48 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*([w = counter(), x = counter(), y = counter(), z = counter()] = [null, 0, false, '']) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-init-undef.js

@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-init-undef.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer with an undefined value (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       [...]
+    7. If environment is undefined, return PutValue(lhs, v).
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x = 23] = [undefined]) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-iter-complete.js

@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-complete.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding when value iteration completes (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x] = []) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-iter-done.js

@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-done.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       [...]
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([_, x] = []) {
+  assert.sameValue(x, undefined);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-id-iter-val.js

@@ -0,0 +1,52 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-id-iter-val.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding when value iteration was completed previously (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([x, y, z] = [1, 2, 3]) {
+  assert.sameValue(x, 1);
+  assert.sameValue(y, 2);
+  assert.sameValue(z, 3);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-obj-id-init.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ x, y, z } = { x: 44, y: 55, z: 66 }] = []) {
+  assert.sameValue(x, 44);
+  assert.sameValue(y, 55);
+  assert.sameValue(z, 66);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-obj-id.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ x, y, z } = { x: 44, y: 55, z: 66 }] = [{ x: 11, y: 22, z: 33 }]) {
+  assert.sameValue(x, 11);
+  assert.sameValue(y, 22);
+  assert.sameValue(z, 33);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-obj-prop-id-init.js

@@ -0,0 +1,54 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }] = []) {
+  assert.sameValue(v, 444);
+  assert.sameValue(x, 555);
+  assert.sameValue(z, 666);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elem-obj-prop-id.js

@@ -0,0 +1,54 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elem-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: BindingElement with object binding pattern and initializer is not used (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingElement : BindingPatternInitializer opt
+
+    [...]
+    2. If iteratorRecord.[[done]] is true, let v be undefined.
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be ? GetValue(defaultValue).
+    4. Return the result of performing BindingInitialization of BindingPattern
+       with v and environment as the arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([{ u: v, w: x, y: z } = { u: 444, w: 555, y: 666 }] = [{ u: 777, w: 888, y: 999 }]) {
+  assert.sameValue(v, 777);
+  assert.sameValue(x, 888);
+  assert.sameValue(z, 999);
+
+  assert.throws(ReferenceError, function() {
+    u;
+  });
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  assert.throws(ReferenceError, function() {
+    y;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elision-exhausted.js

@@ -0,0 +1,49 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Elision accepts exhausted iterator (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       [...]
+    2. Return NormalCompletion(empty).
+
+---*/
+var iter = function*() {}();
+iter.next();
+
+
+var callCount = 0;
+var f;
+f = async function*([,] = iter) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-elision.js

@@ -0,0 +1,58 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-elision.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Elision advances iterator (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([,] = g()) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-empty.js

@@ -0,0 +1,41 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: No iteration occurs for an "empty" array binding pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function*([] = iter) {
+  assert.sameValue(iterations, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-ary-elem.js

@@ -0,0 +1,65 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elem.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing an array BindingElementList pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    4. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+       e. Else,
+          [...]
+          i. Let v be IteratorValue(next).
+          ii. If v is an abrupt completion, set
+              iteratorRecord.[[done]] to true.
+          iii. ReturnIfAbrupt(v).
+    5. If iteratorRecord.[[done]] is true, let v be undefined.
+    [...]
+    8. Return InitializeReferencedBinding(lhs, v).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...[x, y, z]] = [3, 4, 5]) {
+  assert.sameValue(x, 3);
+  assert.sameValue(y, 4);
+  assert.sameValue(z, 5);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-ary-elision.js

@@ -0,0 +1,71 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-elision.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing an elision (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ Elision ]
+
+    1. Return the result of performing
+       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
+       as the argument.
+
+    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation
+
+    Elision : ,
+
+    1. If iteratorRecord.[[done]] is false, then
+       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
+       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
+       c. ReturnIfAbrupt(next).
+       d. If next is false, set iteratorRecord.[[done]] to true.
+    2. Return NormalCompletion(empty).
+
+---*/
+var first = 0;
+var second = 0;
+function* g() {
+  first += 1;
+  yield;
+  second += 1;
+};
+
+
+var callCount = 0;
+var f;
+f = async function*([...[,]] = g()) {
+  assert.sameValue(first, 1);
+  assert.sameValue(second, 1);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-ary-empty.js

@@ -0,0 +1,54 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-empty.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing an "empty" array pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [generators, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    ArrayBindingPattern : [ ]
+
+    1. Return NormalCompletion(empty).
+
+---*/
+var iterations = 0;
+var iter = function*() {
+  iterations += 1;
+}();
+
+
+var callCount = 0;
+var f;
+f = async function*([...[]] = iter) {
+  assert.sameValue(iterations, 1);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-ary-rest.js

@@ -0,0 +1,50 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-ary-rest.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing a rest element (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([...[...x]] = values) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-id-elision.js

@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-elision.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element following elision elements (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    ArrayBindingPattern : [ Elisionopt BindingRestElement ]
+    1. If Elision is present, then
+       a. Let status be the result of performing
+          IteratorDestructuringAssignmentEvaluation of Elision with
+          iteratorRecord as the argument.
+       b. ReturnIfAbrupt(status).
+    2. Return the result of performing IteratorBindingInitialization for
+       BindingRestElement with iteratorRecord and environment as arguments.
+---*/
+var values = [1, 2, 3, 4, 5];
+
+
+var callCount = 0;
+var f;
+f = async function*([ , , ...x] = values) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 3);
+  assert.sameValue(x[1], 4);
+  assert.sameValue(x[2], 5);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-id-exhausted.js

@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id-exhausted.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: RestElement applied to an exhausted iterator (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [Symbol.iterator, async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    1. Let lhs be ResolveBinding(StringValue of BindingIdentifier,
+       environment).
+    2. ReturnIfAbrupt(lhs). 3. Let A be ArrayCreate(0). 4. Let n=0. 5. Repeat,
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. If environment is undefined, return PutValue(lhs, A).
+          ii. Return InitializeReferencedBinding(lhs, A).
+
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([, , ...x] = [1, 2]) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-id.js

@@ -0,0 +1,43 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Lone rest element (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+    BindingRestElement : ... BindingIdentifier
+    [...] 3. Let A be ArrayCreate(0). [...] 5. Repeat
+       [...]
+       f. Let status be CreateDataProperty(A, ToString (n), nextValue).
+       [...]
+---*/
+var values = [1, 2, 3];
+
+
+var callCount = 0;
+var f;
+f = async function*([...x] = values) {
+  assert(Array.isArray(x));
+  assert.sameValue(x.length, 3);
+  assert.sameValue(x[0], 1);
+  assert.sameValue(x[1], 2);
+  assert.sameValue(x[2], 3);
+  assert.notSameValue(x, values);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-init-ary.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-ary.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Reset element (nested array pattern) does not support initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...[ x ] = []] = []) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-init-id.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Reset element (identifier) does not support initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...x = []] = []) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-init-obj.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-init-obj.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Reset element (nested object pattern) does not support initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ x } = []] = []) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-not-final-ary.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-ary.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element (array binding pattern) may not be followed by any element (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...[x], y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-not-final-id.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element (identifier) may not be followed by any element (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...x, y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-not-final-obj.js

@@ -0,0 +1,39 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-not-final-obj.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element (object binding pattern) may not be followed by any element (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+negative:
+  phase: early
+  type: SyntaxError
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+    ArrayBindingPattern[Yield] :
+        [ Elisionopt BindingRestElement[?Yield]opt ]
+        [ BindingElementList[?Yield] ]
+        [ BindingElementList[?Yield] , Elisionopt BindingRestElement[?Yield]opt ]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ x }, y] = [1, 2, 3]) {
+  
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-obj-id.js

@@ -0,0 +1,43 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing an object binding pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ length }] = [1, 2, 3]) {
+  assert.sameValue(length, 3);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-ary-ptrn-rest-obj-prop-id.js

@@ -0,0 +1,51 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/ary-ptrn-rest-obj-prop-id.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Rest element containing an object binding pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.6 Runtime Semantics: IteratorBindingInitialization
+
+    BindingRestElement : ... BindingPattern
+
+    1. Let A be ArrayCreate(0).
+    [...]
+    3. Repeat
+       [...]
+       b. If iteratorRecord.[[done]] is true, then
+          i. Return the result of performing BindingInitialization of
+             BindingPattern with A and environment as the arguments.
+       [...]
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*([...{ 0: v, 1: w, 2: x, 3: y, length: z }] = [7, 8, 9]) {
+  assert.sameValue(v, 7);
+  assert.sameValue(w, 8);
+  assert.sameValue(x, 9);
+  assert.sameValue(y, undefined);
+  assert.sameValue(z, 3);
+
+  assert.throws(ReferenceError, function() {
+    length;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-obj-ptrn-empty.js

@@ -0,0 +1,42 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-empty.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: No property access occurs for an "empty" object binding pattern (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    Runtime Semantics: BindingInitialization
+
+    ObjectBindingPattern : { }
+
+    1. Return NormalCompletion(empty).
+---*/
+var accessCount = 0;
+var obj = Object.defineProperty({}, 'attr', {
+  get: function() {
+    accessCount += 1;
+  }
+});
+
+
+var callCount = 0;
+var f;
+f = async function*({} = obj) {
+  assert.sameValue(accessCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-obj-ptrn-id-init-fn-name-arrow.js

@@ -0,0 +1,43 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-arrow.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to arrow functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ arrow = () => {} } = {}) {
+  assert.sameValue(arrow.name, 'arrow');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-obj-ptrn-id-init-fn-name-class.js

@@ -0,0 +1,45 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-class.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" classes (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ cls = class {}, xCls = class X {}, xCls2 = class { static name() {} } } = {}) {
+  assert.sameValue(cls.name, 'cls');
+  assert.notSameValue(xCls.name, 'xCls');
+  assert.notSameValue(xCls2.name, 'xCls2');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-obj-ptrn-id-init-fn-name-cover.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-cover.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns `name` to "anonymous" functions "through" cover grammar (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ cover = (function () {}), xCover = (0, function() {})  } = {}) {
+  assert.sameValue(cover.name, 'cover');
+  assert.notSameValue(xCover.name, 'xCover');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-obj-ptrn-id-init-fn-name-fn.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-fn.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ fn = function () {}, xFn = function x() {} } = {}) {
+  assert.sameValue(fn.name, 'fn');
+  assert.notSameValue(xFn.name, 'xFn');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-obj-ptrn-id-init-fn-name-gen.js

@@ -0,0 +1,44 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-fn-name-gen.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: SingleNameBinding assigns name to "anonymous" generator functions (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+       d. If IsAnonymousFunctionDefinition(Initializer) is true, then
+          i. Let hasNameProperty be HasOwnProperty(v, "name").
+          ii. ReturnIfAbrupt(hasNameProperty).
+          iii. If hasNameProperty is false, perform SetFunctionName(v,
+               bindingId).
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ gen = function* () {}, xGen = function* x() {} } = {}) {
+  assert.sameValue(gen.name, 'gen');
+  assert.notSameValue(xGen.name, 'xGen');
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-obj-ptrn-id-init-skipped.js

@@ -0,0 +1,47 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-init-skipped.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    SingleNameBinding : BindingIdentifier Initializeropt
+
+    [...]
+    6. If Initializer is present and v is undefined, then
+       [...]
+    [...]
+---*/
+var initCount = 0;
+function counter() {
+  initCount += 1;
+}
+
+
+var callCount = 0;
+var f;
+f = async function*({ w = counter(), x = counter(), y = counter(), z = counter() } = { w: null, x: 0, y: false, z: '' }) {
+  assert.sameValue(w, null);
+  assert.sameValue(x, 0);
+  assert.sameValue(y, false);
+  assert.sameValue(z, '');
+  assert.sameValue(initCount, 0);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-obj-ptrn-id-trailing-comma.js

@@ -0,0 +1,37 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-id-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x, } = { x: 23 }) {
+  assert.sameValue(x, 23);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-obj-ptrn-prop-ary-init.js

@@ -0,0 +1,46 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-init.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Object binding pattern with "nested" array binding pattern using initializer (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3.7 Runtime Semantics: KeyedBindingInitialization
+
+    [...]
+    3. If Initializer is present and v is undefined, then
+       a. Let defaultValue be the result of evaluating Initializer.
+       b. Let v be GetValue(defaultValue).
+       c. ReturnIfAbrupt(v).
+    4. Return the result of performing BindingInitialization for BindingPattern
+       passing v and environment as arguments.
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ w: [x, y, z] = [4, 5, 6] } = {}) {
+  assert.sameValue(x, 4);
+  assert.sameValue(y, 5);
+  assert.sameValue(z, 6);
+
+  assert.throws(ReferenceError, function() {
+    w;
+  });
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);

test/language/expressions/async-generator/dstr-dflt-obj-ptrn-prop-ary-trailing-comma.js

@@ -0,0 +1,37 @@
+// This file was procedurally generated from the following sources:
+// - src/dstr-binding/obj-ptrn-prop-ary-trailing-comma.case
+// - src/dstr-binding/default/async-gen-func-expr-dflt.template
+/*---
+description: Trailing comma is allowed following BindingPropertyList (async generator function expression (default parameter))
+esid: sec-asyncgenerator-definitions-evaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) {
+        AsyncGeneratorBody }
+
+        [...]
+        3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters,
+           AsyncGeneratorBody, scope, strict).
+        [...]
+
+
+    13.3.3 Destructuring Binding Patterns
+
+    ObjectBindingPattern[Yield] :
+        { }
+        { BindingPropertyList[?Yield] }
+        { BindingPropertyList[?Yield] , }
+---*/
+
+
+var callCount = 0;
+var f;
+f = async function*({ x: [y], } = { x: [45] }) {
+  assert.sameValue(y,45);
+  callCount = callCount + 1;
+};
+
+f().next().then(() => {
+    assert.sameValue(callCount, 1, 'invoked exactly once');
+}).then($DONE, $DONE);