1 files changed, 56 insertions, 0 deletions
diff --git a/js/src/tests/test262/language/arguments-object/async-gen-meth-args-trailing-comma-undefined.js b/js/src/tests/test262/language/arguments-object/async-gen-meth-args-trailing-comma-undefined.js
new file mode 100644
index 0000000000..b0cabe0ac6
--- /dev/null
+++ b/js/src/tests/test262/language/arguments-object/async-gen-meth-args-trailing-comma-undefined.js
@@ -0,0 +1,56 @@
+// |reftest| async
+// This file was procedurally generated from the following sources:
+// - src/arguments/args-trailing-comma-undefined.case
+// - src/arguments/default/async-gen-meth.template
+/*---
+description: A trailing comma after undefined should not increase the arguments.length (async generator method)
+esid: sec-asyncgenerator-definitions-propertydefinitionevaluation
+features: [async-iteration]
+flags: [generated, async]
+info: |
+    AsyncGeneratorMethod :
+        async [no LineTerminator here] * PropertyName ( UniqueFormalParameters )
+            { AsyncGeneratorBody }
+
+    1. Let propKey be the result of evaluating PropertyName.
+    2. ReturnIfAbrupt(propKey).
+    3. If the function code for this AsyncGeneratorMethod is strict mode code, let strict be true.
+       Otherwise let strict be false.
+    4. Let scope be the running execution context's LexicalEnvironment.
+    5. Let closure be ! AsyncGeneratorFunctionCreate(Method, UniqueFormalParameters,
+       AsyncGeneratorBody, scope, strict).
+    [...]
+
+
+    Trailing comma in the arguments list
+
+    Left-Hand-Side Expressions
+
+    Arguments :
+        ( )
+        ( ArgumentList )
+        ( ArgumentList , )
+
+    ArgumentList :
+        AssignmentExpression
+        ... AssignmentExpression
+        ArgumentList , AssignmentExpression
+        ArgumentList , ... AssignmentExpression
+---*/
+
+var callCount = 0;
+var obj = {
+  async *method() {
+    assert.sameValue(arguments.length, 2);
+    assert.sameValue(arguments[0], 42);
+    assert.sameValue(arguments[1], undefined);
+    callCount = callCount + 1;
+  }
+};
+
+// Stores a reference `ref` for case evaluation
+var ref = obj.method;
+
+ref(42, undefined,).next().then(() => {
+    assert.sameValue(callCount, 1, 'generator method invoked exactly once');
+}).then($DONE, $DONE);