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// |reftest| shell-option(--enable-explicit-resource-management) skip-if(!(this.hasOwnProperty('getBuildConfiguration')&&getBuildConfiguration('explicit-resource-management'))||!xulRuntime.shell) async -- explicit-resource-management is not enabled unconditionally, requires shell-options
// Copyright (C) 2023 Ron Buckton. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-let-and-const-declarations-runtime-semantics-evaluation
description: Allows undefined in initializer of 'await using'
info: |
RS: Evaluation
AwaitUsingDeclaration : CoverAwaitExpressionAndAwaitUsingDeclarationHead BindingList ;
1. Perform ? BindingEvaluation of BindingList with argument async-dispose.
2. Return empty.
RS: BindingEvaluation
LexicalBinding : BindingIdentifier Initializer
...
5. Return ? InitializeReferencedBinding(lhs, value, hint).
InitializeReferencedBinding ( V, W )
...
4. Return ? base.InitializeBinding(V.[[ReferencedName]], W).
InitializeBinding ( N, V, hint )
...
2. If hint is not normal, perform ? AddDisposableResource(envRec.[[DisposeCapability]], V, hint).
...
AddDisposableResource ( disposeCapability, V, hint [, method ] )
1. If method is not present then,
a. If V is either null or undefined and hint is sync-dispose, then
i. Return unused.
...
...
flags: [async]
includes: [asyncHelpers.js]
features: [explicit-resource-management]
---*/
asyncTest(async function () {
using x = undefined;
});