JSTests/test262/test/language/global-code/script-decl-var.js

// Copyright (C) 2016 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-globaldeclarationinstantiation
es6id: 15.1.8
description: Declaration of variable where permissible
info: |
  [...]
  11. Let declaredVarNames be a new empty List.
  12. For each d in varDeclarations, do
      a. If d is a VariableDeclaration or a ForBinding, then
         i. For each String vn in the BoundNames of d, do
            1. If vn is not an element of declaredFunctionNames, then
               a. Let vnDefinable be ? envRec.CanDeclareGlobalVar(vn).
               b. If vnDefinable is false, throw a TypeError exception.
               c. If vn is not an element of declaredVarNames, then
                  i. Append vn to declaredVarNames.
  [...]
  18. For each String vn in declaredVarNames, in list order do
      a. Perform ? envRec.CreateGlobalVarBinding(vn, false).
  [...]

  8.1.1.4.15 CanDeclareGlobalVar

  1. Let envRec be the global Environment Record for which the method was
     invoked.
  2. Let ObjRec be envRec.[[ObjectRecord]].
  3. Let globalObject be the binding object for ObjRec.
  4. Let hasProperty be ? HasOwnProperty(globalObject, N).
  5. If hasProperty is true, return true.
  6. Return ? IsExtensible(globalObject). 
includes: [propertyHelper.js]
---*/

$262.evalScript('var brandNew;');

assert.sameValue(
  this.brandNew, undefined, 'new binding on an extensible global object'
);
verifyEnumerable(this, 'brandNew');
verifyWritable(this, 'brandNew');
verifyNotConfigurable(this, 'brandNew');

Object.defineProperty(
  this,
  'configurable',
  { configurable: true, writable: false, enumerable: false, value: 0 }
);
Object.defineProperty(
  this,
  'nonConfigurable',
  { configurable: false, writable: false, enumerable: false, value: 0 }
);

// Prevent extensions on the global object to ensure that detail is not
// considered by any of the declarations which follow.
Object.preventExtensions(this);

$262.evalScript('var configurable;');

assert.sameValue(configurable, 0, 'like-named configurable property');
verifyNotEnumerable(this, 'configurable');
verifyNotWritable(this, 'configurable');
verifyConfigurable(this, 'configurable');

$262.evalScript('var nonConfigurable;');

assert.sameValue(nonConfigurable, 0, 'like-named non-configurable property');
verifyNotEnumerable(this, 'nonConfigurable');
verifyNotWritable(this, 'nonConfigurable');
verifyNotConfigurable(this, 'nonConfigurable');