1 files changed, 55 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/AsyncFromSyncIteratorPrototype/return/return-undefined.js b/js/src/tests/test262/built-ins/AsyncFromSyncIteratorPrototype/return/return-undefined.js
new file mode 100644
index 0000000000..5e5e766288
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+++ b/js/src/tests/test262/built-ins/AsyncFromSyncIteratorPrototype/return/return-undefined.js
@@ -0,0 +1,55 @@
+// |reftest| async
+// Copyright (C) 2018 Valerie Young. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-%asyncfromsynciteratorprototype%.throw
+description: return() will return value undefined if sync `return` is undefined
+info: |
+  %AsyncFromSyncIteratorPrototype%.return ( value )
+  ...
+  2. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+  ...
+  5. Let return be GetMethod(syncIterator, "return").
+  6. IfAbruptRejectPromise(return, promiseCapability).
+  7. If return is undefined, then
+    a. Let iterResult be ! CreateIterResultObject(value, true).
+    b. Perform ! Call(promiseCapability.[[Resolve]], undefined, « iterResult »).
+    c. Return promiseCapability.[[Promise]].
+
+flags: [async]
+features: [async-iteration]
+---*/
+
+
+var obj = {
+  [Symbol.iterator]() {
+    return {
+      next() {
+        return { value: 1, done: false };
+      }
+    };
+  }
+};
+
+async function* asyncg() {
+  yield* obj;
+}
+
+var iter = asyncg();
+
+iter.next().then(function(result) {
+
+  iter.return().then(function(result) {
+
+    assert.sameValue(result.done, true, 'the iterator is completed');
+    assert.sameValue(result.value, undefined, 'expect value to be undefined');
+
+    iter.next().then(({ done, value }) => {
+      assert.sameValue(done, true, 'the iterator is completed');
+      assert.sameValue(value, undefined, 'value is undefined');
+    }).then($DONE, $DONE);
+
+  }).catch($DONE);
+
+}).catch($DONE);