third_party/WebKit/LayoutTests/fast/js/script-tests/vardecl-preserve-arguments.js

   1 description(
   2 "This test checks that variable declaration 'var arguments;' doesn't override function's local arguments object."
   3 );
   4
   5 // this test needs to use shouldBe() a bit wrong, since passing the string that
   6 // would evaluate the actual expression (like "typeof arguments" instead of
   7 // "'" + typeof arguments + "'" would use the arguments property that would possibly
   8 // be set by the eval function. We want to test the arguments object that is in
   9 // the current scope
  10
  11 // this tests the overriding of arguments in the top-level funcition block
  12 function argumentsLength() {
  13   var arguments;
  14   shouldBe("'" + typeof arguments + "'", "'object'");
  15   return arguments.length;
  16 }
  17
  18 // this tests the overriding of arguments in a block statement inside function block
  19 function argumentsLengthInnerBlock() {
  20   for (var i=0; i < 1; ++i) {
  21     var arguments;
  22     shouldBe("'" + typeof arguments + "'", "'object'");
  23   }
  24   return arguments.length;
  25 }
  26
  27 function argumentsLengthInnerBlock2() {
  28   var i = 0;
  29   for (var arguments; i > 1; ++i) {
  30     shouldBe("'" + typeof arguments + "'", "'object'");
  31   }
  32   return arguments.length;
  33 }
  34
  35 // this tests that arguments doesn't get overriden by a variable declaration
  36 // with an initializer in a catch block with a parameter of the same name
  37 function argumentsLengthTryCatch() {
  38   try {
  39     throw ["foo"];
  40   } catch (arguments) {
  41     var arguments = ["foo", "bar"];
  42   }
  43
  44   return arguments.length;
  45 }
  46
  47 // this tests that arguments doesn't get overriden by a variable declaration
  48 // with an initializer in a with block where the parameter has a property of
  49 // same name
  50 function argumentsLengthWith() {
  51   var object = { 'arguments': ["foo"] };
  52
  53   with (object) {
  54     var arguments = ["foo", "bar"];
  55   }
  56
  57   return arguments.length;
  58 }
  59
  60 // this tests that arguments can still be overridden
  61 function argumentsLengthOverride() {
  62   shouldBe("'" + typeof arguments + "'", "'object'");
  63   var argslen = arguments.length;
  64
  65   var arguments = [0,1,2,3,5,6,7];
  66
  67   shouldBe("'" + typeof arguments + "'", "'object'");
  68   shouldBe("" + arguments.length, "7");
  69   return argslen;
  70 }
  71
  72 function argumentsLengthOverrideInnerBlock() {
  73   shouldBe("'" + typeof arguments + "'", "'object'");
  74   var argslen = arguments.length;
  75
  76   var i = 0;
  77   for (var arguments = [0,1,2,3,5,6,7]; i < 1; ++i) {
  78       // empty
  79   }
  80
  81   shouldBe("" + arguments.length, "7");
  82
  83   return argslen;
  84 }
  85
  86 function argumentsLengthOverrideInnerBlock2() {
  87   shouldBe("'" + typeof arguments + "'", "'object'");
  88   var argslen = arguments.length;
  89
  90   for (var i = 0; i < 1; ++i) {
  91       var arguments = [0,1,2,3,5,6,7];
  92       // empty
  93   }
  94
  95   shouldBe("" + arguments.length, "7");
  96
  97   return argslen;
  98 }
  99
 100 function argumentsLengthOverrideInnerBlock3() {
 101   shouldBe("'" + typeof arguments + "'", "'object'");
 102   var argslen = arguments.length;
 103   var arguments;
 104   for (var i = 0; i < 1; ++i) {
 105       arguments = [0,1,2,3,5,6,7];
 106       // empty
 107   }
 108
 109   shouldBe("" + arguments.length, "7");
 110
 111   return argslen;
 112 }
 113
 114 function argumentsTearOff1()
 115 {
 116     return argumentsTearOff2(2);
 117 }
 118
 119 function argumentsTearOff2(b)
 120 {
 121     var v = b;
 122     var w = argumentsTearOff1.arguments;
 123     argumentsTearOff3(3);
 124     return v;
 125 }
 126
 127 function argumentsTearOff3(c)
 128 {
 129     var v = c;
 130 }
 131
 132 shouldBe("argumentsLength()", "0");
 133 shouldBe("argumentsLength(1)", "1");
 134 shouldBe("argumentsLength('a','b')", "2");
 135
 136 shouldBe("argumentsLengthInnerBlock()", "0");
 137 shouldBe("argumentsLengthInnerBlock(1)", "1");
 138 shouldBe("argumentsLengthInnerBlock('a','b')", "2");
 139
 140 shouldBe("argumentsLengthInnerBlock2()", "0");
 141 shouldBe("argumentsLengthInnerBlock2(1)", "1");
 142 shouldBe("argumentsLengthInnerBlock2('a','b')", "2");
 143
 144 shouldBe("argumentsLengthTryCatch()", "0");
 145 shouldBe("argumentsLengthWith()", "0");
 146
 147 shouldBe("argumentsLengthOverride()", "0");
 148 shouldBe("argumentsLengthOverride(1)", "1");
 149 shouldBe("argumentsLengthOverride('a','b')", "2");
 150
 151 shouldBe("argumentsLengthOverrideInnerBlock()", "0");
 152 shouldBe("argumentsLengthOverrideInnerBlock(1)", "1");
 153 shouldBe("argumentsLengthOverrideInnerBlock('a','b')", "2");
 154
 155 shouldBe("argumentsLengthOverrideInnerBlock2()", "0");
 156 shouldBe("argumentsLengthOverrideInnerBlock2(1)", "1");
 157 shouldBe("argumentsLengthOverrideInnerBlock2('a','b')", "2");
 158
 159 shouldBe("argumentsLengthOverrideInnerBlock3()", "0");
 160 shouldBe("argumentsLengthOverrideInnerBlock3(1)", "1");
 161 shouldBe("argumentsLengthOverrideInnerBlock3('a','b')", "2");
 162
 163 shouldBe("argumentsTearOff1()", "2");
 164
 165 // this tests that behaviour should persists for
 166 // the program source elements also
 167 shouldBe("typeof undefined", "'undefined'");
 168 shouldBe("'" + typeof arguments + "'", "'undefined'");
 169
 170 var arguments;
 171 shouldBe("typeof arguments", "'object'");
 172 shouldBe("'" + typeof arguments + "'", "'undefined'");
 173
 174 var arguments = [3,2];
 175 shouldBe("'" + typeof arguments + "'", "'object'");
 176 shouldBe("" + arguments.length, "2");