iter-cstm-ctor.js (1327B)
1 // Copyright (C) 2015 the V8 project authors. All rights reserved. 2 // This code is governed by the BSD license found in the LICENSE file. 3 /*--- 4 esid: sec-array.from 5 description: Creating object with custom constructor (traversed via iterator) 6 info: | 7 [...] 8 6. If usingIterator is not undefined, then 9 a. If IsConstructor(C) is true, then 10 i. Let A be Construct(C). 11 b. Else, 12 i. Let A be ArrayCreate(0). 13 c. ReturnIfAbrupt(A). 14 features: [Symbol.iterator] 15 ---*/ 16 17 var thisVal, args; 18 var callCount = 0; 19 var C = function() { 20 thisVal = this; 21 args = arguments; 22 callCount += 1; 23 }; 24 var result; 25 var items = {}; 26 items[Symbol.iterator] = function() { 27 return { 28 next: function() { 29 return { 30 done: true 31 }; 32 } 33 }; 34 }; 35 36 result = Array.from.call(C, items); 37 38 assert( 39 result instanceof C, 'The result of evaluating (result instanceof C) is expected to be true' 40 ); 41 assert.sameValue( 42 result.constructor, 43 C, 44 'The value of result.constructor is expected to equal the value of C' 45 ); 46 assert.sameValue(callCount, 1, 'The value of callCount is expected to be 1'); 47 assert.sameValue(thisVal, result, 'The value of thisVal is expected to equal the value of result'); 48 assert.sameValue(args.length, 0, 'The value of args.length is expected to be 0'); 49 50 reportCompare(0, 0);