async-gen-decl-dstr-array-elem-init-evaluation.js (1596B)
1 // |reftest| async 2 // This file was procedurally generated from the following sources: 3 // - src/dstr-assignment-for-await/array-elem-init-evaluation.case 4 // - src/dstr-assignment-for-await/default/async-gen-decl.template 5 /*--- 6 description: The Initializer should only be evaluated if v is undefined. (for-await-of statement in an async generator declaration) 7 esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation 8 features: [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 flag1 = false, flag2 = false; 29 let _; 30 31 let iterCount = 0; 32 async function * fn() { 33 for await ([ _ = flag1 = true, _ = flag2 = true ] of [[14]]) { 34 assert.sameValue(flag1, false); 35 assert.sameValue(flag2, true); 36 37 38 iterCount += 1; 39 } 40 } 41 42 let promise = fn().next(); 43 44 promise 45 .then(() => assert.sameValue(iterCount, 1, 'iteration occurred as expected'), $DONE) 46 .then($DONE, $DONE);