array-rest-nested-obj-undefined.js (1567B)
1 // This file was procedurally generated from the following sources: 2 // - src/dstr-assignment/array-rest-nested-obj-undefined.case 3 // - src/dstr-assignment/default/for-of.template 4 /*--- 5 description: When DestructuringAssignmentTarget is an obect literal and the iterable is emits no values, an empty array should be used as the value of the nested DestructuringAssignment. (For..of statement) 6 esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation 7 features: [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 var x = null; 28 // Use the the top-level lexical scope for 'length' to provide compatibility with browsers 29 // where length and name are properties of WindowProxy 30 let length; 31 32 var counter = 0; 33 34 for ([...{ 0: x, length }] of [[]]) { 35 assert.sameValue(x, undefined); 36 assert.sameValue(length, 0); 37 counter += 1; 38 } 39 40 assert.sameValue(counter, 1); 41 42 reportCompare(0, 0);