array-elem-trlg-iter-rest-thrw-close.js (2709B)
1 // This file was procedurally generated from the following sources: 2 // - src/dstr-assignment/array-elem-trlg-iter-rest-thrw-close.case 3 // - src/dstr-assignment/error/for-of.template 4 /*--- 5 description: IteratorClose is called when AssignmentRestEvaluation produces a "throw" completion due to reference evaluation (For..of statement) 6 esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation 7 features: [Symbol.iterator, destructuring-binding] 8 flags: [generated] 9 info: | 10 IterationStatement : 11 for ( LeftHandSideExpression of AssignmentExpression ) Statement 12 13 1. Let keyResult be the result of performing ? ForIn/OfHeadEvaluation(« », 14 AssignmentExpression, iterate). 15 2. Return ? ForIn/OfBodyEvaluation(LeftHandSideExpression, Statement, 16 keyResult, assignment, labelSet). 17 18 13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation 19 20 [...] 21 4. If destructuring is true and if lhsKind is assignment, then 22 a. Assert: lhs is a LeftHandSideExpression. 23 b. Let assignmentPattern be the parse of the source text corresponding to 24 lhs using AssignmentPattern as the goal symbol. 25 [...] 26 27 ArrayAssignmentPattern : 28 [ AssignmentElementList , Elisionopt AssignmentRestElementopt ] 29 30 [...] 31 7. If AssignmentRestElement is present, then 32 a. Let status be the result of performing 33 IteratorDestructuringAssignmentEvaluation of AssignmentRestElement 34 with iteratorRecord as the argument. 35 8. If iteratorRecord.[[done]] is false, return IteratorClose(iterator, 36 status). 37 9. Return Completion(status). 38 39 7.4.6 IteratorClose( iterator, completion ) 40 41 [...] 42 6. Let innerResult be Call(return, iterator, « »). 43 [...] 44 45 ---*/ 46 var nextCount = 0; 47 var returnCount = 0; 48 var thisValue = null; 49 var args = null; 50 var iterable = {}; 51 var x; 52 var iterator = { 53 next: function() { 54 nextCount += 1; 55 // Set an upper-bound to limit unnecessary iteration in non-conformant 56 // implementations 57 return { done: nextCount > 10 }; 58 }, 59 return: function() { 60 returnCount += 1; 61 thisValue = this; 62 args = arguments; 63 } 64 }; 65 var thrower = function() { 66 throw new Test262Error(); 67 }; 68 iterable[Symbol.iterator] = function() { 69 return iterator; 70 }; 71 72 var counter = 0; 73 74 assert.throws(Test262Error, function() { 75 for ([ x , ...{}[thrower()] ] of [iterable]) { 76 counter += 1; 77 } 78 counter += 1; 79 }); 80 81 assert.sameValue(counter, 0); 82 83 assert.sameValue(nextCount, 1); 84 assert.sameValue(returnCount, 1); 85 assert.sameValue(thisValue, iterator, 'correct `this` value'); 86 assert(!!args, 'arguments object provided'); 87 assert.sameValue(args.length, 0, 'zero arguments specified'); 88 89 reportCompare(0, 0);