var-ary-ptrn-elem-id-init-skipped.js (1940B)
1 // This file was procedurally generated from the following sources: 2 // - src/dstr-binding/ary-ptrn-elem-id-init-skipped.case 3 // - src/dstr-binding/default/for-of-var.template 4 /*--- 5 description: Destructuring initializer is not evaluated when value is not `undefined` (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 ( var ForBinding of AssignmentExpression ) Statement 12 13 [...] 14 3. Return ForIn/OfBodyEvaluation(ForBinding, Statement, keyResult, 15 varBinding, labelSet). 16 17 13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation 18 19 [...] 20 3. Let destructuring be IsDestructuring of lhs. 21 [...] 22 5. Repeat 23 [...] 24 h. If destructuring is false, then 25 [...] 26 i. Else 27 i. If lhsKind is assignment, then 28 [...] 29 ii. Else if lhsKind is varBinding, then 30 1. Assert: lhs is a ForBinding. 31 2. Let status be the result of performing BindingInitialization 32 for lhs passing nextValue and undefined as the arguments. 33 [...] 34 35 13.3.3.6 Runtime Semantics: IteratorBindingInitialization 36 37 SingleNameBinding : BindingIdentifier Initializeropt 38 39 [...] 40 6. If Initializer is present and v is undefined, then 41 [...] 42 7. If environment is undefined, return PutValue(lhs, v). 43 8. Return InitializeReferencedBinding(lhs, v). 44 ---*/ 45 var initCount = 0; 46 function counter() { 47 initCount += 1; 48 } 49 50 var iterCount = 0; 51 52 for (var [w = counter(), x = counter(), y = counter(), z = counter()] of [[null, 0, false, '']]) { 53 assert.sameValue(w, null); 54 assert.sameValue(x, 0); 55 assert.sameValue(y, false); 56 assert.sameValue(z, ''); 57 assert.sameValue(initCount, 0); 58 59 iterCount += 1; 60 } 61 62 assert.sameValue(iterCount, 1, 'Iteration occurred as expected'); 63 64 reportCompare(0, 0);