| // This file was procedurally generated from the following sources: |
| // - src/dstr-binding/obj-ptrn-prop-id-init-skipped.case |
| // - src/dstr-binding/default/gen-func-decl-dflt.template |
| /*--- |
| description: Destructuring initializer is not evaluated when value is not `undefined` (generator function declaration (default parameter)) |
| esid: sec-generator-function-definitions-runtime-semantics-instantiatefunctionobject |
| features: [generators, destructuring-binding, default-parameters] |
| flags: [generated] |
| info: | |
| GeneratorDeclaration : function * ( FormalParameters ) { GeneratorBody } |
| |
| [...] |
| 2. Let F be GeneratorFunctionCreate(Normal, FormalParameters, |
| GeneratorBody, scope, strict). |
| [...] |
| |
| 9.2.1 [[Call]] ( thisArgument, argumentsList) |
| |
| [...] |
| 7. Let result be OrdinaryCallEvaluateBody(F, argumentsList). |
| [...] |
| |
| 9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList ) |
| |
| 1. Let status be FunctionDeclarationInstantiation(F, argumentsList). |
| [...] |
| |
| 9.2.12 FunctionDeclarationInstantiation(func, argumentsList) |
| |
| [...] |
| 23. Let iteratorRecord be Record {[[iterator]]: |
| CreateListIterator(argumentsList), [[done]]: false}. |
| 24. If hasDuplicates is true, then |
| [...] |
| 25. Else, |
| b. Let formalStatus be IteratorBindingInitialization for formals with |
| iteratorRecord and env as arguments. |
| [...] |
| |
| 13.3.3.7 Runtime Semantics: KeyedBindingInitialization |
| |
| BindingElement : BindingPattern Initializeropt |
| |
| [...] |
| 3. If Initializer is present and v is undefined, then |
| [...] |
| ---*/ |
| var initCount = 0; |
| function counter() { |
| initCount += 1; |
| } |
| |
| var callCount = 0; |
| function* f({ s: t = counter(), u: v = counter(), w: x = counter(), y: z = counter() } = { s: null, u: 0, w: false, y: '' }) { |
| assert.sameValue(t, null); |
| assert.sameValue(v, 0); |
| assert.sameValue(x, false); |
| assert.sameValue(z, ''); |
| assert.sameValue(initCount, 0); |
| |
| assert.throws(ReferenceError, function() { |
| s; |
| }); |
| assert.throws(ReferenceError, function() { |
| u; |
| }); |
| assert.throws(ReferenceError, function() { |
| w; |
| }); |
| assert.throws(ReferenceError, function() { |
| y; |
| }); |
| callCount = callCount + 1; |
| }; |
| f().next(); |
| assert.sameValue(callCount, 1, 'generator function invoked exactly once'); |