| // 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.template |
| /*--- |
| description: Destructuring initializer is not evaluated when value is not `undefined` (async generator function declaration) |
| 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()]) { |
| assert.sameValue(w, null); |
| assert.sameValue(x, 0); |
| assert.sameValue(y, false); |
| assert.sameValue(z, ''); |
| assert.sameValue(initCount, 0); |
| callCount = callCount + 1; |
| }; |
| f([null, 0, false, '']).next().then(() => { |
| assert.sameValue(callCount, 1, 'invoked exactly once'); |
| }).then($DONE, $DONE); |