JSTests/test262/test/built-ins/Map/prototype/keys/does-not-have-mapdata-internal-slot.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: 23.1.3.8
description: >
  Throws a TypeError if `this` object does not have a [[MapData]] internal slot.
info: |
  Map.prototype.keys ()

  1. Let M be the this value.
  2. Return CreateMapIterator(M, "key").

  23.1.5.1 CreateMapIterator Abstract Operation

  ...
  2. If map does not have a [[MapData]] internal slot, throw a TypeError
  exception.
  ...

---*/

var m = new Map();

assert.throws(TypeError, function() {
  Map.prototype.keys.call([]);
});

assert.throws(TypeError, function() {
  m.keys.call([]);
});

assert.throws(TypeError, function() {
  Map.prototype.keys.call({});
});

assert.throws(TypeError, function() {
  m.keys.call({});
});