const-redecl.js revision 85b71799222b55eb5dd74ea26efe0c64ab655c8c 
1// Copyright 2008 the V8 project authors. All rights reserved.
2// Redistribution and use in source and binary forms, with or without
3// modification, are permitted provided that the following conditions are
4// met:
5//
6//     * Redistributions of source code must retain the above copyright
7//       notice, this list of conditions and the following disclaimer.
8//     * Redistributions in binary form must reproduce the above
9//       copyright notice, this list of conditions and the following
10//       disclaimer in the documentation and/or other materials provided
11//       with the distribution.
12//     * Neither the name of Google Inc. nor the names of its
13//       contributors may be used to endorse or promote products derived
14//       from this software without specific prior written permission.
15//
16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
28// Test for const semantics.
29
30
31function CheckException(e) {
32  var string = e.toString();
33  var index = string.indexOf(':');
34  assertTrue(index >= 0);
35  var name = string.slice(0, index);
36  assertTrue(string.indexOf("has already been declared") >= 0 ||
37             string.indexOf("redeclaration") >= 0);
38  if (name == 'SyntaxError') return 'TypeError';
39  return name;
40}
41
42
43function TestLocal(s,e) {
44  try {
45    return eval("(function(){" + s + ";return " + e + "})")();
46  } catch (x) {
47    return CheckException(x);
48  }
49}
50
51
52// NOTE: TestGlobal usually only tests the given string in the context
53// of a global object in dictionary mode. This is because we use
54// delete to get rid of any added properties.
55function TestGlobal(s,e) {
56  // Collect the global properties before the call.
57  var properties = [];
58  for (var key in this) properties.push(key);
59  // Compute the result.
60  var result;
61  try {
62    var code = s + (e ? "; $$$result=" + e : "");
63    if (this.execScript) {
64      execScript(code);
65    } else {
66      this.eval(code);
67    }
68    // Avoid issues if $$$result is not defined by
69    // reading it through this.
70    result = this.$$$result;
71  } catch (x) {
72    result = CheckException(x);
73  }
74  // Get rid of any introduced global properties before
75  // returning the result.
76  for (var key in this) {
77    if (properties.indexOf(key) == -1) delete this[key];
78  }
79  return result;
80}
81
82
83function TestContext(s,e) {
84  try {
85    // Use a with-statement to force the system to do dynamic
86    // declarations of the introduced variables or constants.
87    with ({}) {
88      return eval(s + ";" + e);
89    }
90  } catch (x) {
91    return CheckException(x);
92  }
93}
94
95
96function TestAll(expected,s,opt_e) {
97  var e = "";
98  var msg = s;
99  if (opt_e) { e = opt_e; msg += "; " + opt_e; }
100  assertEquals(expected, TestLocal(s,e), "local:'" + msg + "'");
101  assertEquals(expected, TestGlobal(s,e), "global:'" + msg + "'");
102  assertEquals(expected, TestContext(s,e), "context:'" + msg + "'");
103}
104
105
106function TestConflict(def0, def1) {
107  // No eval.
108  TestAll("TypeError", def0 +'; ' + def1);
109  // Eval everything.
110  TestAll("TypeError", 'eval("' + def0 + '; ' + def1 + '")');
111  // Eval first definition.
112  TestAll("TypeError", 'eval("' + def0 +'"); ' + def1);
113  // Eval second definition.
114  TestAll("TypeError", def0 + '; eval("' + def1 + '")');
115  // Eval both definitions separately.
116  TestAll("TypeError", 'eval("' + def0 +'"); eval("' + def1 + '")');
117}
118
119
120// Test conflicting definitions.
121TestConflict("const x", "var x");
122TestConflict("const x = 0", "var x");
123TestConflict("const x", "var x = 0");
124TestConflict("const x = 0", "var x = 0");
125
126TestConflict("var x", "const x");
127TestConflict("var x = 0", "const x");
128TestConflict("var x", "const x = 0");
129TestConflict("var x = 0", "const x = 0");
130
131TestConflict("const x = undefined", "var x");
132TestConflict("const x", "var x = undefined");
133TestConflict("const x = undefined", "var x = undefined");
134
135TestConflict("var x = undefined", "const x");
136TestConflict("var x", "const x = undefined");
137TestConflict("var x = undefined", "const x = undefined");
138
139TestConflict("const x = undefined", "var x = 0");
140TestConflict("const x = 0", "var x = undefined");
141
142TestConflict("var x = undefined", "const x = 0");
143TestConflict("var x = 0", "const x = undefined");
144
145TestConflict("const x", "function x() { }");
146TestConflict("const x = 0", "function x() { }");
147TestConflict("const x = undefined", "function x() { }");
148
149TestConflict("function x() { }", "const x");
150TestConflict("function x() { }", "const x = 0");
151TestConflict("function x() { }", "const x = undefined");
152
153TestConflict("const x, y", "var x");
154TestConflict("const x, y", "var y");
155TestConflict("const x = 0, y", "var x");
156TestConflict("const x = 0, y", "var y");
157TestConflict("const x, y = 0", "var x");
158TestConflict("const x, y = 0", "var y");
159TestConflict("const x = 0, y = 0", "var x");
160TestConflict("const x = 0, y = 0", "var y");
161
162TestConflict("var x", "const x, y");
163TestConflict("var y", "const x, y");
164TestConflict("var x", "const x = 0, y");
165TestConflict("var y", "const x = 0, y");
166TestConflict("var x", "const x, y = 0");
167TestConflict("var y", "const x, y = 0");
168TestConflict("var x", "const x = 0, y = 0");
169TestConflict("var y", "const x = 0, y = 0");
170
171
172// Test that multiple conflicts do not cause issues.
173TestConflict("var x, y", "const x, y");
174
175
176// Test that repeated const declarations throw redeclaration errors.
177TestConflict("const x", "const x");
178TestConflict("const x = 0", "const x");
179TestConflict("const x", "const x = 0");
180TestConflict("const x = 0", "const x = 0");
181
182TestConflict("const x = undefined", "const x");
183TestConflict("const x", "const x = undefined");
184TestConflict("const x = undefined", "const x = undefined");
185
186TestConflict("const x = undefined", "const x = 0");
187TestConflict("const x = 0", "const x = undefined");
188
189TestConflict("const x, y", "const x");
190TestConflict("const x, y", "const y");
191TestConflict("const x = 0, y", "const x");
192TestConflict("const x = 0, y", "const y");
193TestConflict("const x, y = 0", "const x");
194TestConflict("const x, y = 0", "const y");
195TestConflict("const x = 0, y = 0", "const x");
196TestConflict("const x = 0, y = 0", "const y");
197
198TestConflict("const x", "const x, y");
199TestConflict("const y", "const x, y");
200TestConflict("const x", "const x = 0, y");
201TestConflict("const y", "const x = 0, y");
202TestConflict("const x", "const x, y = 0");
203TestConflict("const y", "const x, y = 0");
204TestConflict("const x", "const x = 0, y = 0");
205TestConflict("const y", "const x = 0, y = 0");
206
207
208// Test that multiple const conflicts do not cause issues.
209TestConflict("const x, y", "const x, y");
210
211
212// Test that const inside loop behaves correctly.
213var loop = "for (var i = 0; i < 3; i++) { const x = i; }";
214TestAll(0, loop, "x");
215TestAll(0, "var a,b,c,d,e,f,g,h; " + loop, "x");
216
217
218// Test that const inside with behaves correctly.
219TestAll(87, "with ({x:42}) { const x = 87; }", "x");
220TestAll(undefined, "with ({x:42}) { const x; }", "x");
221