test262/test/built-ins/Map/map-iterable.js

// Copyright (C) 2015 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
es6id: 23.1.1.1
description: >
  Contructor returns a map object set with the elements from the iterable
  argument.
info: |
  Map ( [ iterable ] )

  ...
  9. Repeat
    a. Let next be IteratorStep(iter).
    b. ReturnIfAbrupt(next).
    c. If next is false, return map.
    ...
---*/

var m = new Map([
  [ "attr", 1 ],
  [ "foo", 2 ]
]);

assert.sameValue(m.size, 2, 'The value of `m.size` is `2`');
assert.sameValue(m.get("attr"), 1);
assert.sameValue(m.get("foo"), 2);