const-ary-ptrn-elem-id-init-skipped.js (2052B)
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-const.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 ( ForDeclaration of AssignmentExpression ) Statement 12 13 [...] 14 3. Return ForIn/OfBodyEvaluation(ForDeclaration, Statement, keyResult, 15 lexicalBinding, 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 [...] 31 iii. Else, 32 1. Assert: lhsKind is lexicalBinding. 33 2. Assert: lhs is a ForDeclaration. 34 3. Let status be the result of performing BindingInitialization 35 for lhs passing nextValue and iterationEnv as arguments. 36 [...] 37 38 13.3.3.6 Runtime Semantics: IteratorBindingInitialization 39 40 SingleNameBinding : BindingIdentifier Initializeropt 41 42 [...] 43 6. If Initializer is present and v is undefined, then 44 [...] 45 7. If environment is undefined, return PutValue(lhs, v). 46 8. Return InitializeReferencedBinding(lhs, v). 47 ---*/ 48 var initCount = 0; 49 function counter() { 50 initCount += 1; 51 } 52 53 var iterCount = 0; 54 55 for (const [w = counter(), x = counter(), y = counter(), z = counter()] of [[null, 0, false, '']]) { 56 assert.sameValue(w, null); 57 assert.sameValue(x, 0); 58 assert.sameValue(y, false); 59 assert.sameValue(z, ''); 60 assert.sameValue(initCount, 0); 61 62 iterCount += 1; 63 } 64 65 assert.sameValue(iterCount, 1, 'iteration occurred as expected'); 66 67 reportCompare(0, 0);