| // Copyright 2015 Microsoft Corporation. All rights reserved. |
| // This code is governed by the license found in the LICENSE file. |
| |
| /*--- |
| esid: sec-array.from |
| description: Calling from with a valid map function with thisArg |
| info: | |
| 22.1.2.1 Array.from ( items [ , mapfn [ , thisArg ] ] ) |
| |
| ... |
| 10. Let len be ToLength(Get(arrayLike, "length")). |
| 11. ReturnIfAbrupt(len). |
| 12. If IsConstructor(C) is true, then |
| a. Let A be Construct(C, «len»). |
| 13. Else, |
| b. Let A be ArrayCreate(len). |
| 14. ReturnIfAbrupt(A). |
| 15. Let k be 0. |
| 16. Repeat, while k < len |
| a. Let Pk be ToString(k). |
| b. Let kValue be Get(arrayLike, Pk). |
| c. ReturnIfAbrupt(kValue). |
| d. If mapping is true, then |
| i. Let mappedValue be Call(mapfn, T, «kValue, k»). |
| ... |
| ---*/ |
| |
| var list = { |
| '0': 41, |
| '1': 42, |
| '2': 43, |
| length: 3 |
| }; |
| var calls = []; |
| var thisArg = {}; |
| |
| function mapFn(value) { |
| calls.push({ |
| args: arguments, |
| thisArg: this |
| }); |
| return value * 2; |
| } |
| |
| var result = Array.from(list, mapFn, thisArg); |
| |
| assert.sameValue(result.length, 3, 'result.length'); |
| assert.sameValue(result[0], 82, 'result[0]'); |
| assert.sameValue(result[1], 84, 'result[1]'); |
| assert.sameValue(result[2], 86, 'result[2]'); |
| |
| assert.sameValue(calls.length, 3, 'calls.length'); |
| |
| assert.sameValue(calls[0].args.length, 2, 'calls[0].args.length'); |
| assert.sameValue(calls[0].args[0], 41, 'calls[0].args[0]'); |
| assert.sameValue(calls[0].args[1], 0, 'calls[0].args[1]'); |
| assert.sameValue(calls[0].thisArg, thisArg, 'calls[0].thisArg'); |
| |
| assert.sameValue(calls[1].args.length, 2, 'calls[1].args.length'); |
| assert.sameValue(calls[1].args[0], 42, 'calls[1].args[0]'); |
| assert.sameValue(calls[1].args[1], 1, 'calls[1].args[1]'); |
| assert.sameValue(calls[1].thisArg, thisArg, 'calls[1].thisArg'); |
| |
| assert.sameValue(calls[2].args.length, 2, 'calls[2].args.length'); |
| assert.sameValue(calls[2].args[0], 43, 'calls[2].args[0]'); |
| assert.sameValue(calls[2].args[1], 2, 'calls[2].args[1]'); |
| assert.sameValue(calls[2].thisArg, thisArg, 'calls[2].thisArg'); |