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

// Copyright (C) 2017 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 )

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

//- setup
let nextCount = 0;
let returnCount = 0;
let thisValue = null;
let args = null;
let iterator = {
  next() {
    nextCount += 1;
    return { done: true };
  },
  return() {
    returnCount += 1;
    thisValue = this;
    args = arguments;
    return {};
  }
};
let iterable = {
  [Symbol.iterator]() {
    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');


//- teardown
iter.next()
  .then(() => assert.sameValue(iterCount, 1, 'iteration occurred as expected'), $DONE)
  .then($DONE, $DONE);