src/dstr-assignment/array-empty-iter-close.case

// Copyright (C) 2016 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
desc: Iterator is closed without iterating
info: |
    ArrayAssignmentPattern : [ ]

    1. Let iterator be GetIterator(value).
    2. ReturnIfAbrupt(iterator).
    3. Return IteratorClose(iterator, NormalCompletion(empty)).

    7.4.6 IteratorClose( iterator, completion )

    [...]
    6. Let innerResult be Call(return, iterator, « »).
    [...]
features: [Symbol.iterator]
template: default
esid: sec-runtime-semantics-destructuringassignmentevaluation
---*/

//- setup
var nextCount = 0;
var returnCount = 0;
var thisValue = null;
var args = null;
var iterable = {};
var iterator = {
  next: function() {
    nextCount += 1;
    return { done: true };
  },
  return: function() {
    returnCount += 1;
    thisValue = this;
    args = arguments;
    return {};
  }
};
iterable[Symbol.iterator] = function() {
  return iterator;
};
//- elems
[]
//- vals
iterable
//- body
assert.sameValue(nextCount, 0);
assert.sameValue(returnCount, 1);
assert.sameValue(thisValue, iterator, 'correct `this` value');
assert(!!args, 'arguments object provided');
assert.sameValue(args.length, 0, 'zero arguments specified');