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

   1 /*
   2 * The contents of this file are subject to the Netscape Public
   3 * License Version 1.1 (the "License"); you may not use this file
   4 * except in compliance with the License. You may obtain a copy of
   5 * the License at http://www.mozilla.org/NPL/
   6 *
   7 * Software distributed under the License is distributed on an "AS
   8 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
   9 * implied. See the License for the specific language governing
  10 * rights and limitations under the License.
  11 *
  12 * The Original Code is mozilla.org code.
  13 *
  14 * The Initial Developer of the Original Code is Netscape
  15 * Communications Corporation.  Portions created by Netscape are
  16 * Copyright (C) 1998 Netscape Communications Corporation. All
  17 * Rights Reserved.
  18 *
  19 * Contributor(s): pschwartau@netscape.com, rogerl@netscape.com
  20 * Date: 28 May 2001
  21 *
  22 * SUMMARY:  Functions are scoped statically, not dynamically
  23 *
  24 * See ECMA Section 10.1.4 Scope Chain and Identifier Resolution
  25 * (This section defines the scope chain of an execution context)
  26 *
  27 * See ECMA Section 12.10 The with Statement
  28 *
  29 * See ECMA Section 13 Function Definition
  30 * (This section defines the scope chain of a function object as that
  31 *  of the running execution context when the function was declared)
  32 */
  33 //-------------------------------------------------------------------------------------------------
  34 var UBound = 0;
  35 var bug = '(none)';
  36 var summary = 'Testing that functions are scoped statically, not dynamically';
  37 var self = this;  // capture a reference to the global object
  38 var status = '';
  39 var statusitems = [ ];
  40 var actual = '';
  41 var actualvalues = [ ];
  42 var expect= '';
  43 var expectedvalues = [ ];
  44
  45 /*
  46  * In this section the expected value is 1, not 2.
  47  *
  48  * Why? f captures its scope chain from when it's declared, and imposes that chain
  49  * when it's executed. In other words, f's scope chain is from when it was compiled.
  50  * Since f is a top-level function, this is the global object only. Hence 'a' resolves to 1.
  51  */
  52 status = 'Section A of test';
  53 var a = 1;
  54 function f()
  55 {
  56   return a;
  57 }
  58 var obj = {a:2};
  59 with (obj)
  60 {
  61   actual = f();
  62 }
  63 expect = 1;
  64 addThis();
  65
  66
  67 /*
  68  * In this section the expected value is 2, not 1. That is because here
  69  * f's associated scope chain now includes 'obj' before the global object.
  70  */
  71 status = 'Section B of test';
  72 var a = 1;
  73 var obj = {a:2};
  74 with (obj)
  75 {
  76   function f()
  77   {
  78     return a;
  79   }
  80   actual = f();
  81 }
  82 // Mozilla result, which contradicts IE and the ECMA spec: expect = 2;
  83 expect = 1;
  84 addThis();
  85
  86
  87 /*
  88  * Like Section B , except that we call f outside the with block.
  89  * By the principles explained above, we still expect 2 -
  90  */
  91 status = 'Section C of test';
  92 var a = 1;
  93 var obj = {a:2};
  94 with (obj)
  95 {
  96   function f()
  97   {
  98     return a;
  99   }
 100 }
 101 actual = f();
 102 // Mozilla result, which contradicts IE and the ECMA spec: expect = 2;
 103 expect = 1;
 104 addThis();
 105
 106
 107 /*
 108  * Like Section C, but with one more level of indirection -
 109  */
 110 status = 'Section D of test';
 111 var a = 1;
 112 var obj = {a:2, obj:{a:3}};
 113 with (obj)
 114 {
 115   with (obj)
 116   {
 117     function f()
 118     {
 119       return a;
 120     }
 121   }
 122 }
 123 actual = f();
 124 // Mozilla result, which contradicts IE and the ECMA spec: expect = 3;
 125 expect = 1;
 126 addThis();
 127
 128
 129 /*
 130  * Like Section C, but here we actually delete obj before calling f.
 131  * We still expect 2 -
 132  */
 133 status = 'Section E of test';
 134 var a = 1;
 135 var obj = {a:2};
 136 with (obj)
 137 {
 138   function f()
 139   {
 140     return a;
 141   }
 142 }
 143 delete obj;
 144 actual = f();
 145 // Mozilla result, which contradicts IE and the ECMA spec: expect = 2;
 146 expect = 1;
 147 addThis();
 148
 149
 150 /*
 151  * Like Section E. Here we redefine obj and call f under with (obj) -
 152  * We still expect 2 -
 153  */
 154 status = 'Section F of test';
 155 var a = 1;
 156 var obj = {a:2};
 157 with (obj)
 158 {
 159   function f()
 160   {
 161     return a;
 162   }
 163 }
 164 delete obj;
 165 var obj = {a:3};
 166 with (obj)
 167 {
 168   actual = f();
 169 }
 170 // Mozilla result, which contradicts IE and the ECMA spec: expect = 2;  // NOT 3 !!!
 171 expect = 1;
 172 addThis();
 173
 174
 175 /*
 176  * Explicitly verify that f exists at global level, even though
 177  * it was defined under the with(obj) block -
 178  */
 179 status = 'Section G of test';
 180 var a = 1;
 181 var obj = {a:2};
 182 with (obj)
 183 {
 184   function f()
 185   {
 186     return a;
 187   }
 188 }
 189 actual = String([obj.hasOwnProperty('f'), self.hasOwnProperty('f')]);
 190 expect = String([false, true]);
 191 addThis();
 192
 193
 194 /*
 195  * Explicitly verify that f exists at global level, even though
 196  * it was defined under the with(obj) block -
 197  */
 198 status = 'Section H of test';
 199 var a = 1;
 200 var obj = {a:2};
 201 with (obj)
 202 {
 203   function f()
 204   {
 205     return a;
 206   }
 207 }
 208 actual = String(['f' in obj, 'f' in self]);
 209 expect = String([false, true]);
 210 addThis();
 211
 212
 213
 214 //-------------------------------------------------------------------------------------------------
 215 test();
 216 //-------------------------------------------------------------------------------------------------
 217
 218
 219 function addThis()
 220 {
 221   statusitems[UBound] = status;
 222   actualvalues[UBound] = actual;
 223   expectedvalues[UBound] = expect;
 224   UBound++;
 225   resetTestVars();
 226 }
 227
 228
 229 function resetTestVars()
 230 {
 231   delete a;
 232   delete obj;
 233   delete f;
 234 }
 235
 236
 237 function test()
 238 {
 239   enterFunc ('test');
 240   printBugNumber (bug);
 241   printStatus (summary);
 242
 243   for (var i = 0; i < UBound; i++)
 244   {
 245     reportCompare(expectedvalues[i], actualvalues[i], statusitems[i]);
 246   }
 247
 248   exitFunc ('test');
 249 }