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// |reftest| error:SyntaxError
// Copyright 2016 Microsoft, Inc. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
author: Brian Terlson <brian.terlson@microsoft.com>
esid: sec-async-arrow-function-definitions
description: Formal parameters may not contain duplicates
info: |
# 14.2 Arrow Function Definitions
When the production
ArrowParameters:CoverParenthesizedExpressionAndArrowParameterList
is recognized the following grammar is used to refine the interpretation
of CoverParenthesizedExpressionAndArrowParameterList:
ArrowFormalParameters[Yield, Await]:
(UniqueFormalParameters[?Yield, ?Await])
# 14.1.2 Static Semantics: Early Errors
UniqueFormalParameters:FormalParameters
- It is a Syntax Error if BoundNames of FormalParameters contains any
duplicate elements.
negative:
phase: parse
type: SyntaxError
features: [async-functions]
---*/
$DONOTEVALUATE();
async(a, a) => { }