JSTests/test262/test/language/statements/for-of/dstr/array-empty-iter-close.js

// This file was procedurally generated from the following sources:
// - src/dstr-assignment/array-empty-iter-close.case
// - src/dstr-assignment/default/for-of.template
/*---
description: Iterator is closed without iterating (For..of statement)
esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation
es6id: 13.7.5.11
features: [Symbol.iterator, destructuring-binding]
flags: [generated]
info: |
    IterationStatement :
      for ( LeftHandSideExpression of AssignmentExpression ) Statement

    1. Let keyResult be the result of performing ? ForIn/OfHeadEvaluation(« »,
       AssignmentExpression, iterate).
    2. Return ? ForIn/OfBodyEvaluation(LeftHandSideExpression, Statement,
       keyResult, assignment, labelSet).

    13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation

    [...]
    4. If destructuring is true and if lhsKind is assignment, then
       a. Assert: lhs is a LeftHandSideExpression.
       b. Let assignmentPattern be the parse of the source text corresponding to
          lhs using AssignmentPattern as the goal symbol.
    [...]

    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, « »).
    [...]

---*/
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;
};

var counter = 0;

for ([] of [iterable]) {
  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');
  counter += 1;
}

assert.sameValue(counter, 1);