The Tor Browser: js/src/tests/ecma_3/Function/scope-002.js@6474c204b198 (annotated)

js/src/tests/ecma_3/Function/scope-002.js@6474c204b198 (annotated)

js/src/tests/ecma_3/Function/scope-002.js

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /*
  * 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)
  *
  * Like scope-001.js, but using assignment var f = function expression
  * instead of a function declaration: function f() {} etc.
  */
 //-----------------------------------------------------------------------------
 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;
 var f = function () {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)
 {
   var f = function () {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)
 {
   var f = function () {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)
   {
     var f = function () {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)
 {
   var f = function () {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)
 {
   var f = function () {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)
 {
   var f = function () {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)
 {
   var f = function () {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');
 }