1 files changed, 105 insertions, 0 deletions
diff --git a/js/src/tests/test262/language/statements/async-generator/yield-return-then-getter-ticks.js b/js/src/tests/test262/language/statements/async-generator/yield-return-then-getter-ticks.js
new file mode 100644
index 0000000000..2a3b580a91
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-generator/yield-return-then-getter-ticks.js
@@ -0,0 +1,105 @@
+// |reftest| async
+// Copyright (C) 2019 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-generator-function-definitions-runtime-semantics-evaluation
+description: >
+  Return resumption value is awaited upon and hence is treated as a thenable.
+info: |
+  14.4.14 Runtime Semantics: Evaluation
+    YieldExpression : yield AssignmentExpression
+
+    ...
+    3. Let value be ? GetValue(exprRef).
+    4. If generatorKind is async, then return ? AsyncGeneratorYield(value).
+    ...
+
+  25.5.3.7 AsyncGeneratorYield ( value )
+    ...
+    5. Set value to ? Await(value).
+    ...
+    8. Set the code evaluation state of genContext such that when evaluation is resumed with a
+       Completion resumptionValue the following steps will be performed:
+      ...
+      b. Let awaited be Await(resumptionValue.[[Value]]).
+      ...
+      e. Return Completion { [[Type]]: return, [[Value]]: awaited.[[Value]], [[Target]]: empty }.
+      ...
+
+  6.2.3.1 Await
+    ...
+    2. Let promise be ? PromiseResolve(%Promise%, « value »).
+    ...
+
+  25.6.4.5.1 PromiseResolve ( C, x )
+    ...
+    3. Let promiseCapability be ? NewPromiseCapability(C).
+    4. Perform ? Call(promiseCapability.[[Resolve]], undefined, « x »).
+    ...
+
+  25.6.1.5 NewPromiseCapability ( C )
+    ...
+    7. Let promise be ? Construct(C, « executor »).
+    ...
+
+  25.6.3.1 Promise ( executor )
+    ...
+    8. Let resolvingFunctions be CreateResolvingFunctions(promise).
+    ...
+
+  25.6.1.3 CreateResolvingFunctions ( promise )
+    ...
+    2. Let stepsResolve be the algorithm steps defined in Promise Resolve Functions (25.6.1.3.2).
+    3. Let resolve be CreateBuiltinFunction(stepsResolve, « [[Promise]], [[AlreadyResolved]] »).
+    ...
+
+  25.6.1.3.2 Promise Resolve Functions
+    ...
+    9. Let then be Get(resolution, "then").
+    ...
+
+includes: [compareArray.js]
+flags: [async]
+features: [async-iteration]
+---*/
+
+var expected = [
+  "start",
+
+  // `Await(value)` promise resolved.
+  "tick 1",
+
+  // "then" of `resumptionValue.[[Value]]` accessed.
+  "get then",
+
+  // `Await(resumptionValue.[[Value]])` promise resolved.
+  "tick 2",
+];
+
+var actual = [];
+
+async function* f() {
+  actual.push("start");
+  yield 123;
+  actual.push("stop - never reached");
+}
+
+Promise.resolve(0)
+  .then(() => actual.push("tick 1"))
+  .then(() => actual.push("tick 2"))
+  .then(() => {
+    assert.compareArray(actual, expected, "Ticks for return with thenable getter");
+}).then($DONE, $DONE);
+
+var it = f();
+
+// Start generator execution.
+it.next();
+
+// Stop generator execution.
+it.return({
+  get then() {
+    actual.push("get then");
+  }
+});