async-gen-decl-dstr-array-rest-iteration.js (1625B)
1 // |reftest| async 2 // This file was procedurally generated from the following sources: 3 // - src/dstr-assignment-for-await/array-rest-iteration.case 4 // - src/dstr-assignment-for-await/default/async-gen-decl.template 5 /*--- 6 description: In the presense of an AssignmentRestElement, value iteration exhausts the iterable value; (for-await-of statement in an async generator declaration) 7 esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation 8 features: [generators, 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 let count = 0; 29 let g = function*() { 30 count += 1; 31 yield; 32 count += 1; 33 yield; 34 count += 1; 35 } 36 let x; 37 38 let iterCount = 0; 39 async function * fn() { 40 for await ([...x] of [g()]) { 41 assert.sameValue(count, 3); 42 43 iterCount += 1; 44 } 45 } 46 47 let promise = fn().next(); 48 49 promise 50 .then(() => assert.sameValue(iterCount, 1, 'iteration occurred as expected'), $DONE) 51 .then($DONE, $DONE);