test262/test/language/expressions/assignment/dstr-array-elem-trlg-iter-rest-thrw-close-err.js

// This file was procedurally generated from the following sources:
// - src/dstr-assignment/array-elem-trlg-iter-rest-thrw-close-err.case
// - src/dstr-assignment/error/assignment-expr.template
/*---
description: IteratorClose is called when AssignmentRestEvaluation produces a "throw" completion due to reference evaluation (AssignmentExpression)
esid: sec-variable-statement-runtime-semantics-evaluation
es6id: 13.3.2.4
features: [Symbol.iterator, destructuring-binding]
flags: [generated]
info: |
    VariableDeclaration : BindingPattern Initializer

    1. Let rhs be the result of evaluating Initializer.
    2. Let rval be GetValue(rhs).
    3. ReturnIfAbrupt(rval).
    4. Return the result of performing BindingInitialization for
       BindingPattern passing rval and undefined as arguments.

    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 )

    [...]
    7. If completion.[[type]] is throw, return Completion(completion)

---*/
var nextCount = 0;
var returnCount = 0;
var x;
function ReturnError() {}
var iterable = {};
var iterator = {
  next: function() {
    nextCount += 1;
    // Set an upper-bound to limit unnecessary iteration in non-conformant
    // implementations
    return { done: nextCount > 10 };
  },
  return: function() {
    returnCount += 1;

    // This value should be discarded.
    throw new ReturnError();
  }
};
var thrower = function() {
  throw new Test262Error();
};
iterable[Symbol.iterator] = function() {
  return iterator;
};

assert.throws(Test262Error, function() {
  0, [ x , ...{}[thrower()] ] = iterable;
});

assert.sameValue(nextCount, 1);
assert.sameValue(returnCount, 1);