JSTests/test262/test/language/statements/function/dstr-dflt-ary-ptrn-rest-ary-elision.js

// This file was procedurally generated from the following sources:
// - src/dstr-binding/ary-ptrn-rest-ary-elision.case
// - src/dstr-binding/default/func-decl-dflt.template
/*---
description: Rest element containing an elision (function declaration (default parameter))
esid: sec-function-definitions-runtime-semantics-instantiatefunctionobject
es6id: 14.1.19
features: [generators, destructuring-binding, default-parameters]
flags: [generated]
info: |
    FunctionDeclaration :
        function BindingIdentifier ( FormalParameters ) { FunctionBody }

        [...]
        3. Let F be FunctionCreate(Normal, FormalParameters, FunctionBody,
           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.
    [...]

    13.3.3.6 Runtime Semantics: IteratorBindingInitialization

    BindingRestElement : ... BindingPattern

    1. Let A be ArrayCreate(0).
    [...]
    3. Repeat
       [...]
       b. If iteratorRecord.[[done]] is true, then
          i. Return the result of performing BindingInitialization of
             BindingPattern with A and environment as the arguments.
       [...]

    13.3.3.6 Runtime Semantics: IteratorBindingInitialization

    ArrayBindingPattern : [ Elision ]

    1. Return the result of performing
       IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord
       as the argument.

    12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation

    Elision : ,

    1. If iteratorRecord.[[done]] is false, then
       a. Let next be IteratorStep(iteratorRecord.[[iterator]]).
       b. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
       c. ReturnIfAbrupt(next).
       d. If next is false, set iteratorRecord.[[done]] to true.
    2. Return NormalCompletion(empty).

---*/
var first = 0;
var second = 0;
function* g() {
  first += 1;
  yield;
  second += 1;
};

var callCount = 0;
function f([...[,]] = g()) {
  assert.sameValue(first, 1);
  assert.sameValue(second, 1);
  callCount = callCount + 1;
};
f();
assert.sameValue(callCount, 1, 'function invoked exactly once');