michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * Date: 28 May 2001
michael@0:  *
michael@0:  * SUMMARY:  Functions are scoped statically, not dynamically
michael@0:  *
michael@0:  * See ECMA Section 10.1.4 Scope Chain and Identifier Resolution
michael@0:  * (This section defines the scope chain of an execution context)
michael@0:  *
michael@0:  * See ECMA Section 12.10 The with Statement
michael@0:  *
michael@0:  * See ECMA Section 13 Function Definition
michael@0:  * (This section defines the scope chain of a function object as that
michael@0:  *  of the running execution context when the function was declared)
michael@0:  *
michael@0:  * Like scope-001.js, but using assignment var f = function expression
michael@0:  * instead of a function declaration: function f() {} etc.
michael@0:  */
michael@0: //-----------------------------------------------------------------------------
michael@0: var UBound = 0;
michael@0: var BUGNUMBER = '(none)';
michael@0: var summary = 'Testing that functions are scoped statically, not dynamically';
michael@0: var self = this;  // capture a reference to the global object
michael@0: var status = '';
michael@0: var statusitems = [ ];
michael@0: var actual = '';
michael@0: var actualvalues = [ ];
michael@0: var expect= '';
michael@0: var expectedvalues = [ ];
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * In this section the expected value is 1, not 2.
michael@0:  *
michael@0:  * Why? f captures its scope chain from when it's declared, and imposes that chain
michael@0:  * when it's executed. In other words, f's scope chain is from when it was compiled.
michael@0:  * Since f is a top-level function, this is the global object only. Hence 'a' resolves to 1.
michael@0:  */
michael@0: status = 'Section A of test';
michael@0: var a = 1;
michael@0: var f = function () {return a;};
michael@0: var obj = {a:2};
michael@0: with (obj)
michael@0: {
michael@0:   actual = f();
michael@0: }
michael@0: expect = 1;
michael@0: addThis();
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * In this section the expected value is 2, not 1. That is because here
michael@0:  * f's associated scope chain now includes 'obj' before the global object.
michael@0:  */
michael@0: status = 'Section B of test';
michael@0: var a = 1;
michael@0: var obj = {a:2};
michael@0: with (obj)
michael@0: {
michael@0:   var f = function () {return a;};
michael@0:   actual = f();
michael@0: }
michael@0: expect = 2;
michael@0: addThis();
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Like Section B , except that we call f outside the with block.
michael@0:  * By the principles explained above, we still expect 2 -
michael@0:  */
michael@0: status = 'Section C of test';
michael@0: var a = 1;
michael@0: var obj = {a:2};
michael@0: with (obj)
michael@0: {
michael@0:   var f = function () {return a;};
michael@0: }
michael@0: actual = f();
michael@0: expect = 2;
michael@0: addThis();
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Like Section C, but with one more level of indirection -
michael@0:  */
michael@0: status = 'Section D of test';
michael@0: var a = 1;
michael@0: var obj = {a:2, obj:{a:3}};
michael@0: with (obj)
michael@0: {
michael@0:   with (obj)
michael@0:   {
michael@0:     var f = function () {return a;};
michael@0:   }
michael@0: }
michael@0: actual = f();
michael@0: expect = 3;
michael@0: addThis();
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Like Section C, but here we actually delete obj before calling f.
michael@0:  * We still expect 2 -
michael@0:  */
michael@0: status = 'Section E of test';
michael@0: var a = 1;
michael@0: var obj = {a:2};
michael@0: with (obj)
michael@0: {
michael@0:   var f = function () {return a;};
michael@0: }
michael@0: delete obj;
michael@0: actual = f();
michael@0: expect = 2;
michael@0: addThis();
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Like Section E. Here we redefine obj and call f under with (obj) -
michael@0:  * We still expect 2 -
michael@0:  */
michael@0: status = 'Section F of test';
michael@0: var a = 1;
michael@0: var obj = {a:2};
michael@0: with (obj)
michael@0: {
michael@0:   var f = function () {return a;};
michael@0: }
michael@0: delete obj;
michael@0: var obj = {a:3};
michael@0: with (obj)
michael@0: {
michael@0:   actual = f();
michael@0: }
michael@0: expect = 2;  // NOT 3 !!!
michael@0: addThis();
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Explicitly verify that f exists at global level, even though
michael@0:  * it was defined under the with(obj) block -
michael@0:  */
michael@0: status = 'Section G of test';
michael@0: var a = 1;
michael@0: var obj = {a:2};
michael@0: with (obj)
michael@0: {
michael@0:   var f = function () {return a;};
michael@0: }
michael@0: actual = String([obj.hasOwnProperty('f'), self.hasOwnProperty('f')]);
michael@0: expect = String([false, true]);
michael@0: addThis();
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Explicitly verify that f exists at global level, even though
michael@0:  * it was defined under the with(obj) block -
michael@0:  */
michael@0: status = 'Section H of test';
michael@0: var a = 1;
michael@0: var obj = {a:2};
michael@0: with (obj)
michael@0: {
michael@0:   var f = function () {return a;};
michael@0: }
michael@0: actual = String(['f' in obj, 'f' in self]);
michael@0: expect = String([false, true]);
michael@0: addThis();
michael@0: 
michael@0: 
michael@0: 
michael@0: //-------------------------------------------------------------------------------------------------
michael@0: test();
michael@0: //-------------------------------------------------------------------------------------------------
michael@0: 
michael@0: 
michael@0: function addThis()
michael@0: {
michael@0:   statusitems[UBound] = status;
michael@0:   actualvalues[UBound] = actual;
michael@0:   expectedvalues[UBound] = expect;
michael@0:   UBound++;
michael@0:   resetTestVars();
michael@0: }
michael@0: 
michael@0: 
michael@0: function resetTestVars()
michael@0: {
michael@0:   delete a;
michael@0:   delete obj;
michael@0:   delete f;
michael@0: }
michael@0: 
michael@0: 
michael@0: function test()
michael@0: {
michael@0:   enterFunc ('test');
michael@0:   printBugNumber(BUGNUMBER);
michael@0:   printStatus (summary);
michael@0: 
michael@0:   for (var i = 0; i < UBound; i++)
michael@0:   {
michael@0:     reportCompare(expectedvalues[i], actualvalues[i], statusitems[i]);
michael@0:   }
michael@0: 
michael@0:   exitFunc ('test');
michael@0: }