js/src/tests/test262/language/statements/for-of/dstr/obj-rest-val-undefined.js


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41

// This file was procedurally generated from the following sources:
// - src/dstr-assignment/obj-rest-val-undefined.case
// - src/dstr-assignment/error/for-of.template
/*---
description: TypeError is thrown when rhs is ```undefined``` because of 7.1.13 ToObject ( argument ) used by CopyDataProperties (For..of statement)
esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation
features: [object-rest, 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.
    [...]
---*/
var rest;

var counter = 0;

assert.throws(TypeError, function() {
  for ({...rest} of [undefined
]) {
    counter += 1;
  }
  counter += 1;
});

assert.sameValue(counter, 0);

reportCompare(0, 0);