dflt-ary-ptrn-elem-id-init-undef.js (1927B)
1 // This file was procedurally generated from the following sources: 2 // - src/dstr-binding/ary-ptrn-elem-id-init-undef.case 3 // - src/dstr-binding/default/arrow-function-dflt.template 4 /*--- 5 description: Destructuring initializer with an undefined value (arrow function expression (default parameter)) 6 esid: sec-arrow-function-definitions-runtime-semantics-evaluation 7 features: [destructuring-binding, default-parameters] 8 flags: [generated] 9 info: | 10 ArrowFunction : ArrowParameters => ConciseBody 11 12 [...] 13 4. Let closure be FunctionCreate(Arrow, parameters, ConciseBody, scope, strict). 14 [...] 15 16 9.2.1 [[Call]] ( thisArgument, argumentsList) 17 18 [...] 19 7. Let result be OrdinaryCallEvaluateBody(F, argumentsList). 20 [...] 21 22 9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList ) 23 24 1. Let status be FunctionDeclarationInstantiation(F, argumentsList). 25 [...] 26 27 9.2.12 FunctionDeclarationInstantiation(func, argumentsList) 28 29 [...] 30 23. Let iteratorRecord be Record {[[iterator]]: 31 CreateListIterator(argumentsList), [[done]]: false}. 32 24. If hasDuplicates is true, then 33 [...] 34 25. Else, 35 b. Let formalStatus be IteratorBindingInitialization for formals with 36 iteratorRecord and env as arguments. 37 [...] 38 39 13.3.3.6 Runtime Semantics: IteratorBindingInitialization 40 41 SingleNameBinding : BindingIdentifier Initializeropt 42 43 [...] 44 6. If Initializer is present and v is undefined, then 45 a. Let defaultValue be the result of evaluating Initializer. 46 b. Let v be GetValue(defaultValue). 47 [...] 48 7. If environment is undefined, return PutValue(lhs, v). 49 8. Return InitializeReferencedBinding(lhs, v). 50 ---*/ 51 52 var callCount = 0; 53 var f; 54 f = ([x = 23] = [undefined]) => { 55 assert.sameValue(x, 23); 56 callCount = callCount + 1; 57 }; 58 59 f(); 60 assert.sameValue(callCount, 1, 'arrow function invoked exactly once'); 61 62 reportCompare(0, 0);