1 files changed, 39 insertions, 0 deletions
diff --git a/js/src/tests/test262/language/statements/async-function/dflt-params-duplicates.js b/js/src/tests/test262/language/statements/async-function/dflt-params-duplicates.js
new file mode 100644
index 0000000000..2ea2494afb
--- /dev/null
+++ b/js/src/tests/test262/language/statements/async-function/dflt-params-duplicates.js
@@ -0,0 +1,39 @@
+// |reftest| error:SyntaxError
+// This file was procedurally generated from the following sources:
+// - src/function-forms/dflt-params-duplicates.case
+// - src/function-forms/syntax/async-func-decl.template
+/*---
+description: It is a Syntax Error if BoundNames of FormalParameters contains any duplicate elements. (async function declaration)
+esid: sec-async-function-definitions
+features: [default-parameters, async-functions]
+flags: [generated]
+negative:
+  phase: parse
+  type: SyntaxError
+info: |
+    14.6 Async Function Definitions
+
+    AsyncFunctionDeclaration :
+      async function BindingIdentifier ( FormalParameters ) { AsyncFunctionBody }
+
+
+    14.1.2 Static Semantics: Early Errors
+
+    StrictFormalParameters : FormalParameters
+
+    - It is a Syntax Error if BoundNames of FormalParameters contains any
+      duplicate elements.
+
+    FormalParameters : FormalParameterList
+
+    - It is a Syntax Error if IsSimpleParameterList of FormalParameterList is
+      false and BoundNames of FormalParameterList contains any duplicate
+      elements.
+
+---*/
+$DONOTEVALUATE();
+
+
+async function f(x = 0, x) {
+  
+}