Test closing async-from-sync iterator when resolving result promise abrupt completes. (#3977)

* Test closing async-from-sync iterator when resolving result promise abrupt completes.

These test new steps 6-6.a of AsyncFromSyncIteratorContinuation
as per normative changes of ecma626 PR 2600
https://github.com/tc39/ecma262/pull/2600

* Apply suggestions from code review

Co-authored-by: Kevin Gibbons <bakkot@gmail.com>

* Apply suggestions from code review

Co-authored-by: Nicolò Ribaudo <hello@nicr.dev>

* Refactoring tests to use the Async Helpers.

---------

Co-authored-by: Kevin Gibbons <bakkot@gmail.com>
Co-authored-by: Nicolò Ribaudo <hello@nicr.dev>

test/built-ins/AsyncFromSyncIteratorPrototype/next/iterator-result-poisoned-wrapper.js

@@ -0,0 +1,67 @@
+// Copyright (C) 2023 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-%asyncfromsynciteratorprototype%.next
+description: next() will reject promise if resolving result promise abrupt completes.
+info: |
+  %AsyncFromSyncIteratorPrototype%.next ( value )
+  ...
+  3. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+  4. Let syncIteratorRecord be O.[[SyncIteratorRecord]].
+  5. If value is present, then
+    ...
+  6. Else,
+    a. Let result be IteratorNext(syncIteratorRecord).
+  7. IfAbruptRejectPromise(result, promiseCapability).
+  8. Return ! AsyncFromSyncIteratorContinuation(result, promiseCapability, syncIteratorRecord, true).
+
+  AsyncFromSyncIteratorContinuation ( result, promiseCapability, syncIteratorRecord, closeOnRejection )
+  1. Let done be IteratorComplete(result).
+  2. IfAbruptRejectPromise(done, promiseCapability).
+  3. Let value be IteratorValue(result).
+  4. IfAbruptRejectPromise(value, promiseCapability).
+  5. Let valueWrapper be PromiseResolve(%Promise%, value).
+  6. If valueWrapper is an abrupt completion, done is false, and closeOnRejection is true, then
+    a. Set valueWrapper to IteratorClose(syncIteratorRecord, valueWrapper).
+  7. IfAbruptRejectPromise(valueWrapper, promiseCapability).
+  ...
+
+  IfAbruptRejectPromise ( value, capability )
+  1. Assert: value is a Completion Record.
+  2. If value is an abrupt completion, then
+    a. Perform ? Call(capability.[[Reject]], undefined, « value.[[Value]] »).
+    b. Return capability.[[Promise]].
+  ...
+
+flags: [async]
+features: [async-iteration]
+includes: [asyncHelpers.js]
+---*/
+
+var finallyCount = 0;
+function CatchError() {}
+var thrownError = new CatchError();
+
+function* gen() {
+  try {
+    const p = Promise.resolve('FAIL');
+    Object.defineProperty(p, 'constructor', {
+      get() {
+        throw thrownError;
+      }
+    });
+    yield p;
+  } finally {
+    finallyCount += 1;
+  }
+}
+
+async function* iter() {
+  yield* gen();
+}
+
+asyncTest(async function () {
+  await assert.throwsAsync(CatchError, async () => iter().next(), "Promise should be rejected");
+  assert.sameValue(finallyCount, 1, 'iterator closed properly');
+})

test/built-ins/AsyncFromSyncIteratorPrototype/next/next-result-poisoned-wrapper.js

@@ -0,0 +1,72 @@
+// Copyright (C) 2023 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-%asyncfromsynciteratorprototype%.next
+description: next() will reject promise if resolving result promise abrupt completes.
+info: |
+  %AsyncFromSyncIteratorPrototype%.next ( value )
+  ...
+  3. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+  4. Let syncIteratorRecord be O.[[SyncIteratorRecord]].
+  5. If value is present, then
+    ...
+  6. Else,
+    a. Let result be IteratorNext(syncIteratorRecord).
+  7. IfAbruptRejectPromise(result, promiseCapability).
+  8. Return ! AsyncFromSyncIteratorContinuation(result, promiseCapability, syncIteratorRecord, true).
+
+  AsyncFromSyncIteratorContinuation ( result, promiseCapability, syncIteratorRecord, closeOnRejection )
+  1. Let done be IteratorComplete(result).
+  2. IfAbruptRejectPromise(done, promiseCapability).
+  3. Let value be IteratorValue(result).
+  4. IfAbruptRejectPromise(value, promiseCapability).
+  5. Let valueWrapper be PromiseResolve(%Promise%, value).
+  6. If valueWrapper is an abrupt completion, done is false, and closeOnRejection is true, then
+    a. Set valueWrapper to IteratorClose(syncIteratorRecord, valueWrapper).
+  7. IfAbruptRejectPromise(valueWrapper, promiseCapability).
+  ...
+
+  IfAbruptRejectPromise ( value, capability )
+  1. Assert: value is a Completion Record.
+  2. If value is an abrupt completion, then
+    a. Perform ? Call(capability.[[Reject]], undefined, « value.[[Value]] »).
+    b. Return capability.[[Promise]].
+  ...
+
+flags: [async]
+features: [async-iteration]
+includes: [asyncHelpers.js]
+---*/
+
+var returnCount = 0;
+function CatchError() {}
+var thrownError = new CatchError();
+
+const obj = {
+  [Symbol.iterator]() {
+    return {
+      next() {
+        const p = Promise.resolve('FAIL');
+        Object.defineProperty(p, 'constructor', {
+          get() {
+            throw thrownError;
+          }
+        });
+        return { value: p, done: false };
+      },
+      return() {
+        returnCount += 1;
+      }
+    };
+  }
+};
+
+async function* iter() {
+  yield* obj;
+}
+
+asyncTest(async function () {
+  await assert.throwsAsync(CatchError, async () => iter().next(), "Promise should be rejected");
+  assert.sameValue(returnCount, 1, 'iterator closed properly');
+})

test/built-ins/AsyncFromSyncIteratorPrototype/throw/throw-result-poisoned-wrapper.js

@@ -0,0 +1,90 @@
+// Copyright (C) 2023 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-%asyncfromsynciteratorprototype%.throw
+description: throw() will reject promise if resolving result promise abrupt completes.
+info: |
+  %AsyncFromSyncIteratorPrototype%.throw ( value )
+  ...
+  3. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+  4. Let syncIteratorRecord be O.[[SyncIteratorRecord]].
+  5. Let syncIterator be syncIteratorRecord.[[Iterator]].
+  6. Let throw be GetMethod(syncIterator, "throw").
+  7. IfAbruptRejectPromise(throw, promiseCapability).
+  8. If throw is undefined, then
+    ...
+  9. If value is present, then
+    ...
+  10. Else,
+    a. Let result be Call(throw, syncIterator).
+  ...
+  13. Return ! AsyncFromSyncIteratorContinuation(result, promiseCapability, syncIteratorRecord, true).
+
+  AsyncFromSyncIteratorContinuation ( result, promiseCapability, syncIteratorRecord, closeOnRejection )
+  1. Let done be IteratorComplete(result).
+  2. IfAbruptRejectPromise(done, promiseCapability).
+  3. Let value be IteratorValue(result).
+  4. IfAbruptRejectPromise(value, promiseCapability).
+  5. Let valueWrapper be PromiseResolve(%Promise%, value).
+  6. If valueWrapper is an abrupt completion, done is false, and closeOnRejection is true, then
+    a. Set valueWrapper to IteratorClose(syncIteratorRecord, valueWrapper).
+  7. IfAbruptRejectPromise(valueWrapper, promiseCapability).
+  ...
+
+  IfAbruptRejectPromise ( value, capability )
+  1. Assert: value is a Completion Record.
+  2. If value is an abrupt completion, then
+    a. Perform ? Call(capability.[[Reject]], undefined, « value.[[Value]] »).
+    b. Return capability.[[Promise]].
+  ...
+
+flags: [async]
+features: [async-iteration]
+includes: [asyncHelpers.js]
+---*/
+
+var returnCount = 0;
+function CatchError() {}
+var thrownError = new CatchError();
+var uncaughtError = new Error("Don't catch me");
+
+const obj = {
+  [Symbol.iterator]() {
+    return {
+      next() {
+        return { value: 1, done: false };
+      },
+      throw() {
+        const p = Promise.resolve('FAIL');
+        Object.defineProperty(p, 'constructor', {
+          get() {
+            throw thrownError;
+          }
+        });
+        return { value: p, done: false };
+      },
+      return() {
+        returnCount += 1;
+        return { value: undefined, done: true };
+      }
+    };
+  }
+};
+
+async function* asyncg() {
+  return yield* obj;
+}
+
+let iter = asyncg();
+
+asyncTest(async function () {
+  await assert.throwsAsync(CatchError, async () => {
+    await iter.next();
+    return iter.throw(uncaughtError);
+  }, "Promise should be rejected");
+  assert.sameValue(returnCount, 1, 'iterator closed properly');
+  const result = await iter.next();
+  assert(result.done, "the iterator is completed");
+  assert.sameValue(result.value, undefined, "value is undefined");
+})