gecko/js/tests/ecma_3/Function/scope-001.js

266 lines
5.8 KiB
JavaScript

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* pschwartau@netscape.com, rogerl@netscape.com
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* Date: 28 May 2001
*
* SUMMARY: Functions are scoped statically, not dynamically
*
* See ECMA Section 10.1.4 Scope Chain and Identifier Resolution
* (This section defines the scope chain of an execution context)
*
* See ECMA Section 12.10 The with Statement
*
* See ECMA Section 13 Function Definition
* (This section defines the scope chain of a function object as that
* of the running execution context when the function was declared)
*/
//-----------------------------------------------------------------------------
var gTestfile = 'scope-001.js';
var UBound = 0;
var BUGNUMBER = '(none)';
var summary = 'Testing that functions are scoped statically, not dynamically';
var self = this; // capture a reference to the global object
var status = '';
var statusitems = [ ];
var actual = '';
var actualvalues = [ ];
var expect= '';
var expectedvalues = [ ];
/*
* In this section the expected value is 1, not 2.
*
* Why? f captures its scope chain from when it's declared, and imposes that chain
* when it's executed. In other words, f's scope chain is from when it was compiled.
* Since f is a top-level function, this is the global object only. Hence 'a' resolves to 1.
*/
status = 'Section A of test';
var a = 1;
function f()
{
return a;
}
var obj = {a:2};
with (obj)
{
actual = f();
}
expect = 1;
addThis();
/*
* In this section the expected value is 2, not 1. That is because here
* f's associated scope chain now includes 'obj' before the global object.
*/
status = 'Section B of test';
var a = 1;
var obj = {a:2};
with (obj)
{
function f()
{
return a;
}
actual = f();
}
expect = 2;
addThis();
/*
* Like Section B , except that we call f outside the with block.
* By the principles explained above, we still expect 2 -
*/
status = 'Section C of test';
var a = 1;
var obj = {a:2};
with (obj)
{
function f()
{
return a;
}
}
actual = f();
expect = 2;
addThis();
/*
* Like Section C, but with one more level of indirection -
*/
status = 'Section D of test';
var a = 1;
var obj = {a:2, obj:{a:3}};
with (obj)
{
with (obj)
{
function f()
{
return a;
}
}
}
actual = f();
expect = 3;
addThis();
/*
* Like Section C, but here we actually delete obj before calling f.
* We still expect 2 -
*/
status = 'Section E of test';
var a = 1;
var obj = {a:2};
with (obj)
{
function f()
{
return a;
}
}
delete obj;
actual = f();
expect = 2;
addThis();
/*
* Like Section E. Here we redefine obj and call f under with (obj) -
* We still expect 2 -
*/
status = 'Section F of test';
var a = 1;
var obj = {a:2};
with (obj)
{
function f()
{
return a;
}
}
delete obj;
var obj = {a:3};
with (obj)
{
actual = f();
}
expect = 2; // NOT 3 !!!
addThis();
/*
* Explicitly verify that f exists at global level, even though
* it was defined under the with(obj) block -
*/
status = 'Section G of test';
var a = 1;
var obj = {a:2};
with (obj)
{
function f()
{
return a;
}
}
actual = String([obj.hasOwnProperty('f'), self.hasOwnProperty('f')]);
expect = String([false, true]);
addThis();
/*
* Explicitly verify that f exists at global level, even though
* it was defined under the with(obj) block -
*/
status = 'Section H of test';
var a = 1;
var obj = {a:2};
with (obj)
{
function f()
{
return a;
}
}
actual = String(['f' in obj, 'f' in self]);
expect = String([false, true]);
addThis();
//-------------------------------------------------------------------------------------------------
test();
//-------------------------------------------------------------------------------------------------
function addThis()
{
statusitems[UBound] = status;
actualvalues[UBound] = actual;
expectedvalues[UBound] = expect;
UBound++;
resetTestVars();
}
function resetTestVars()
{
delete a;
delete obj;
delete f;
}
function test()
{
enterFunc ('test');
printBugNumber(BUGNUMBER);
printStatus (summary);
for (var i = 0; i < UBound; i++)
{
reportCompare(expectedvalues[i], actualvalues[i], statusitems[i]);
}
exitFunc ('test');
}