dflt-ary-ptrn-elem-id-init-undef.js (1401B)
1 // |reftest| async 2 // This file was procedurally generated from the following sources: 3 // - src/dstr-binding/ary-ptrn-elem-id-init-undef.case 4 // - src/dstr-binding/default/async-gen-func-expr-dflt.template 5 /*--- 6 description: Destructuring initializer with an undefined value (async generator function expression (default parameter)) 7 esid: sec-asyncgenerator-definitions-evaluation 8 features: [async-iteration] 9 flags: [generated, async] 10 info: | 11 AsyncGeneratorExpression : async [no LineTerminator here] function * ( FormalParameters ) { 12 AsyncGeneratorBody } 13 14 [...] 15 3. Let closure be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, 16 AsyncGeneratorBody, scope, strict). 17 [...] 18 19 20 13.3.3.6 Runtime Semantics: IteratorBindingInitialization 21 22 SingleNameBinding : BindingIdentifier Initializeropt 23 24 [...] 25 6. If Initializer is present and v is undefined, then 26 a. Let defaultValue be the result of evaluating Initializer. 27 b. Let v be GetValue(defaultValue). 28 [...] 29 7. If environment is undefined, return PutValue(lhs, v). 30 8. Return InitializeReferencedBinding(lhs, v). 31 ---*/ 32 33 34 var callCount = 0; 35 var f; 36 f = async function*([x = 23] = [undefined]) { 37 assert.sameValue(x, 23); 38 callCount = callCount + 1; 39 }; 40 41 f().next().then(() => { 42 assert.sameValue(callCount, 1, 'invoked exactly once'); 43 }).then($DONE, $DONE);