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452c0e5c61
* Automated assertion message update: Array.from * Automated assertion message update: Array.isArray * Automated assertion message update: Array length property * Automated assertion message update: Array.of * Automated assertion message update: Array * Automated assertion message update: Array.prototype.at * Automated assertion message update: Array.prototype.concat * Automated assertion message update: compareArray -> assert.compareArray
40 lines
1.1 KiB
JavaScript
40 lines
1.1 KiB
JavaScript
// Copyright (c) 2014 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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/*---
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esid: sec-array.from
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description: >
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If this is a constructor, and items doesn't have an @@iterator,
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returns a new instance of this
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info: |
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22.1.2.1 Array.from ( items [ , mapfn [ , thisArg ] ] )
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4. Let usingIterator be GetMethod(items, @@iterator).
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...
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6. If usingIterator is not undefined, then
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...
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12. If IsConstructor(C) is true, then
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a. Let A be Construct(C, «len»).
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13. Else,
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a. Let A be ArrayCreate(len).
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...
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19. Return A.
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---*/
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var result;
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function MyCollection() {
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this.args = arguments;
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}
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result = Array.from.call(MyCollection, {
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length: 42
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});
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assert.sameValue(result.args.length, 1, 'The value of result.args.length is expected to be 1');
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assert.sameValue(result.args[0], 42, 'The value of result.args[0] is expected to be 42');
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assert(
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result instanceof MyCollection,
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'The result of evaluating (result instanceof MyCollection) is expected to be true'
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);
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