// |reftest| async // This file was procedurally generated from the following sources: // - src/dstr-binding/ary-ptrn-elem-id-init-skipped.case // - src/dstr-binding/default/async-gen-func-decl-dflt.template /*--- description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function declaration (default parameter)) esid: sec-asyncgenerator-definitions-instantiatefunctionobject features: [async-iteration] flags: [generated, async] info: | AsyncGeneratorDeclaration : async [no LineTerminator here] function * BindingIdentifier ( FormalParameters ) { AsyncGeneratorBody } [...] 3. Let F be ! AsyncGeneratorFunctionCreate(Normal, FormalParameters, AsyncGeneratorBody, scope, strict). [...] 13.3.3.6 Runtime Semantics: IteratorBindingInitialization SingleNameBinding : BindingIdentifier Initializeropt [...] 6. If Initializer is present and v is undefined, then [...] 7. If environment is undefined, return PutValue(lhs, v). 8. Return InitializeReferencedBinding(lhs, v). ---*/ var initCount = 0; function counter() { initCount += 1; } var callCount = 0; async function* f([w = counter(), x = counter(), y = counter(), z = counter()] = [null, 0, false, '']) { assert.sameValue(w, null); assert.sameValue(x, 0); assert.sameValue(y, false); assert.sameValue(z, ''); assert.sameValue(initCount, 0); callCount = callCount + 1; }; f().next().then(() => { assert.sameValue(callCount, 1, 'invoked exactly once'); }).then($DONE, $DONE);