// Copyright (C) 2016 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
path: language/statements/generators/dstr-dflt-
name: generator function declaration (default parameter)
esid: sec-generator-function-definitions-runtime-semantics-instantiatefunctionobject
es6id: 14.4.12
features: [generators, destructuring-binding, default-parameters]
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.
    [...]
---*/

var callCount = 0;
function* f(/*{ elems }*/ = /*{ vals }*/) {
  /*{ body }*/
  callCount = callCount + 1;
};
f().next();
assert.sameValue(callCount, 1, 'generator function invoked exactly once');