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