1 files changed, 43 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/AsyncGeneratorFunction/instance-yield-expr-in-param.js b/js/src/tests/test262/built-ins/AsyncGeneratorFunction/instance-yield-expr-in-param.js
new file mode 100644
index 0000000000..06a877cf93
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+++ b/js/src/tests/test262/built-ins/AsyncGeneratorFunction/instance-yield-expr-in-param.js
@@ -0,0 +1,43 @@
+// |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-asyncgeneratorfunction
+description: Definition of instance `length` property
+info: |
+    AsyncGeneratorFunction ( p1, p2, … , pn, body )
+    ...
+    3. Return CreateDynamicFunction(C, NewTarget, "async generator", args).
+
+    Runtime Semantics: CreateDynamicFunction
+    ...
+    28. If kind is "generator" or "async generator", then
+        a. If parameters Contains YieldExpression is true, throw a SyntaxError
+           exception.
+features: [async-iteration]
+flags: [async]
+---*/
+
+var AsyncGeneratorFunction = Object.getPrototypeOf(async function* () {}).constructor;
+
+// YieldExpression is permitted in function body.
+AsyncGeneratorFunction('x = yield');
+
+assert.throws(SyntaxError, function() {
+  AsyncGeneratorFunction('x = yield', '');
+}, 'YieldExpression not permitted generally');
+
+var withinAsyncGenerator = async function*() {
+  AsyncGeneratorFunction('x = yield', '');
+};
+
+withinAsyncGenerator().next().then(
+ function () {
+   throw new Test262Error("YieldExpression not permitted when calling context is a async generator");
+ },
+ function (e) {
+   if (!(e instanceof SyntaxError)) {
+    throw new Test262Error("Expected SyntaxError but got " + e);
+   }
+ }
+).then($DONE, $DONE);