async-gen-decl-dstr-array-rest-iter-nrml-close-skip.js (2163B)
1 // |reftest| async 2 // This file was procedurally generated from the following sources: 3 // - src/dstr-assignment-for-await/array-rest-iter-nrml-close-skip.case 4 // - src/dstr-assignment-for-await/async-generator/async-gen-decl.template 5 /*--- 6 description: IteratorClose is not called when assignment evaluation has exhausted the iterator (for-await-of statement in an async generator declaration) 7 esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation 8 features: [Symbol.iterator, destructuring-binding, async-iteration] 9 flags: [generated, async] 10 info: | 11 IterationStatement : 12 for await ( LeftHandSideExpression of AssignmentExpression ) Statement 13 14 1. Let keyResult be the result of performing ? ForIn/OfHeadEvaluation(« », 15 AssignmentExpression, iterate). 16 2. Return ? ForIn/OfBodyEvaluation(LeftHandSideExpression, Statement, 17 keyResult, assignment, labelSet). 18 19 13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation 20 21 [...] 22 5. If destructuring is true and if lhsKind is assignment, then 23 a. Assert: lhs is a LeftHandSideExpression. 24 b. Let assignmentPattern be the parse of the source text corresponding to 25 lhs using AssignmentPattern as the goal symbol. 26 [...] 27 28 ArrayAssignmentPattern : [ Elisionopt AssignmentRestElement ] 29 30 [...] 31 4. Let result be the result of performing 32 IteratorDestructuringAssignmentEvaluation of AssignmentRestElement 33 with iteratorRecord as the argument. 34 5. If iteratorRecord.[[Done]] is false, return ? IteratorClose(iterator, result). 35 6. Return result. 36 37 ---*/ 38 let nextCount = 0; 39 let returnCount = 0; 40 let x; 41 let iterator = { 42 next() { 43 nextCount += 1; 44 return { done: true }; 45 }, 46 return() { 47 returnCount += 1; 48 } 49 }; 50 let iterable = { 51 [Symbol.iterator]() { 52 return iterator; 53 } 54 }; 55 56 let iterCount = 0; 57 async function * fn() { 58 for await ([ ...x ] of [iterable]) { 59 assert.sameValue(nextCount, 1); 60 assert.sameValue(returnCount, 0); 61 62 iterCount += 1; 63 } 64 } 65 66 let iter = fn(); 67 68 iter.next() 69 .then(() => assert.sameValue(iterCount, 1, 'iteration occurred as expected'), $DONE) 70 .then($DONE, $DONE);