async-gen-decl-dstr-array-rest-elision.js (1664B)
1 // |reftest| async 2 // This file was procedurally generated from the following sources: 3 // - src/dstr-assignment-for-await/array-rest-elision.case 4 // - src/dstr-assignment-for-await/default/async-gen-decl.template 5 /*--- 6 description: ArrayAssignmentPattern may include elisions at any position preceding a AssignmentRestElement in a AssignmentElementList. (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 x, y; 29 30 let iterCount = 0; 31 async function * fn() { 32 for await ([, , x, , ...y] of [[1, 2, 3, 4, 5, 6]]) { 33 assert.sameValue(x, 3); 34 assert.sameValue(y.length, 2); 35 assert.sameValue(y[0], 5); 36 assert.sameValue(y[1], 6); 37 38 39 40 iterCount += 1; 41 } 42 } 43 44 let promise = fn().next(); 45 46 promise 47 .then(() => assert.sameValue(iterCount, 1, 'iteration occurred as expected'), $DONE) 48 .then($DONE, $DONE);