src/dstr-assignment/array-elem-trlg-iter-rest-rtrn-close-null.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: >
    IteratorClose throws a TypeError when `return` returns a non-Object value
info: |
    ArrayAssignmentPattern :
        [ AssignmentElementList , Elisionopt AssignmentRestElementopt ]

    [...]
    7. If AssignmentRestElement is present, then
       a. Let status be the result of performing
          IteratorDestructuringAssignmentEvaluation of AssignmentRestElement
          with iteratorRecord as the argument.
    8. If iteratorRecord.[[done]] is false, return IteratorClose(iterator,
       status).
    9. Return Completion(status).

    7.4.6 IteratorClose( iterator, completion )

    [...]
    6. Let innerResult be Call(return, iterator, « »).
    7. If completion.[[type]] is throw, return Completion(completion).
    8. If innerResult.[[type]] is throw, return Completion(innerResult).
features: [Symbol.iterator, generators]
template: default
esid: sec-runtime-semantics-destructuringassignmentevaluation
---*/

//- setup
var nextCount = 0;
var iterable = {};
var x;
var iterator = {
  next: function() {
    nextCount += 1;
    // Set an upper-bound to limit unnecessary iteration in non-conformant
    // implementations
    return { done: nextCount > 10 };
  },
  return: function() {
    return null;
  }
};
var iter;
iterable[Symbol.iterator] = function() {
  return iterator;
};

function* g() {
//- elems
[ x , ...{}[yield] ]
//- vals
iterable
//- teardown
}

iter = g();
iter.next();

assert.throws(TypeError, function() {
  iter.return();
});

assert.sameValue(nextCount, 1);