array-elem-trlg-iter-elision-iter-abpt.js (2311B)
1 // This file was procedurally generated from the following sources: 2 // - src/dstr-assignment/array-elem-trlg-iter-elision-iter-abpt.case 3 // - src/dstr-assignment/error/for-of.template 4 /*--- 5 description: Abrupt completion returned during evaluation of elision (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 6. If Elision is present, then 32 a. Let status be the result of performing 33 IteratorDestructuringAssignmentEvaluation of Elision with 34 iteratorRecord as the argument. 35 b. If status is an abrupt completion, then 36 i. If iteratorRecord.[[done]] is false, return 37 IteratorClose(iterator, status). 38 ii. Return Completion(status). 39 40 ---*/ 41 var nextCount = 0; 42 var returnCount = 0; 43 var iterable = {}; 44 var x; 45 var iterator = { 46 next: function() { 47 nextCount += 1; 48 49 if (nextCount === 2) { 50 throw new Test262Error(); 51 } 52 53 // Set an upper-bound to limit unnecessary iteration in non-conformant 54 // implementations 55 return { done: nextCount > 10 }; 56 }, 57 return: function() { 58 returnCount += 1; 59 } 60 }; 61 iterable[Symbol.iterator] = function() { 62 return iterator; 63 }; 64 65 66 var counter = 0; 67 68 assert.throws(Test262Error, function() { 69 for ([ x , , ] of [iterable]) { 70 counter += 1; 71 } 72 counter += 1; 73 }); 74 75 assert.sameValue(counter, 0); 76 77 assert.sameValue(nextCount, 2); 78 assert.sameValue(returnCount, 0); 79 80 reportCompare(0, 0);