test262/src/dstr-assignment/array-rest-iter-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 : [ Elisionopt AssignmentRestElement ]

    [...]
    5. Let result be the result of performing
       IteratorDestructuringAssignmentEvaluation of AssignmentRestElement with
       iteratorRecord as the argument
    6. If iteratorRecord.[[done]] is false, return IteratorClose(iterator,
       result).

    AssignmentRestElement[Yield] : ... DestructuringAssignmentTarget

    1. If DestructuringAssignmentTarget is neither an ObjectLiteral nor an
       ArrayLiteral, then
       a. Let lref be the result of evaluating DestructuringAssignmentTarget.
       b. ReturnIfAbrupt(lref).

    7.4.6 IteratorClose( iterator, completion )

    [...]
    6. Let innerResult be Call(return, iterator, « »).
    [...]

    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 iterable = {};
var iterator = {
  return: function() {
    return null;
  }
};
var iter;
iterable[Symbol.iterator] = function() {
  return iterator;
};

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

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

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