JSTests/test262/test/language/expressions/assignment/dstr/array-elem-iter-rtrn-close.js

// This file was procedurally generated from the following sources:
// - src/dstr-assignment/array-elem-iter-rtrn-close.case
// - src/dstr-assignment/default/assignment-expr.template
/*---
description: IteratorClose is called when reference evaluation produces a "return" completion (AssignmentExpression)
esid: sec-variable-statement-runtime-semantics-evaluation
features: [Symbol.iterator, generators, 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 ]

    [...]
    5. If iteratorRecord.[[done]] is false, return IteratorClose(iterator,
       result).
    6. Return result.

    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).

---*/
var nextCount = 0;
var returnCount = 0;
var unreachable = 0;
var thisValue = null;
var args = null;
var iterator = {
  next: function() {
    nextCount += 1;
    return {done: false, value: undefined};
  },
  return: function() {
    returnCount += 1;
    thisValue = this;
    args = arguments;
    return {};
  }
};
var iterable = {};
iterable[Symbol.iterator] = function() {
  return iterator;
};

function* g() {

var result;
var vals = iterable;

result = [ {} = yield ] = vals;

unreachable += 1;

assert.sameValue(result, vals);

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

assert.sameValue(nextCount, 1);
assert.sameValue(returnCount, 0);

var result = iter.return(777);

assert.sameValue(nextCount, 1);
assert.sameValue(returnCount, 1);
assert.sameValue(unreachable, 0, 'Unreachable statement was not executed');
assert.sameValue(result.value, 777);
assert(result.done, 'Iterator correctly closed');
assert.sameValue(thisValue, iterator, 'correct `this` value');
assert(!!args, 'arguments object provided');
assert.sameValue(args.length, 0, 'zero arguments specified');