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
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
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11 // with the distribution.
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13 // contributors may be used to endorse or promote products derived
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16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 // Test for const semantics.
31 function 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';
43 function TestLocal(s,e) {
45 return eval("(function(){" + s + ";return " + e + "})")();
47 return CheckException(x);
52 function TestContext(s,e) {
54 // Use a with-statement to force the system to do dynamic
55 // declarations of the introduced variables or constants.
57 return eval(s + ";" + e);
60 return CheckException(x);
65 function TestAll(expected,s,opt_e) {
68 if (opt_e) { e = opt_e; msg += "; " + opt_e; }
69 assertEquals(expected, TestLocal(s,e), "local:'" + msg + "'");
70 assertEquals(expected, TestContext(s,e), "context:'" + msg + "'");
74 function TestConflict(def0, def1) {
76 TestAll("TypeError", def0 +'; ' + def1);
78 TestAll("TypeError", 'eval("' + def0 + '; ' + def1 + '")');
79 // Eval first definition.
80 TestAll("TypeError", 'eval("' + def0 +'"); ' + def1);
81 // Eval second definition.
82 TestAll("TypeError", def0 + '; eval("' + def1 +'")');
83 // Eval both definitions separately.
84 TestAll("TypeError", 'eval("' + def0 +'"); eval("' + def1 + '")');
88 // Test conflicting definitions.
89 TestConflict("const x", "var x");
90 TestConflict("const x = 0", "var x");
91 TestConflict("const x", "var x = 0");
92 TestConflict("const x = 0", "var x = 0");
94 TestConflict("var x", "const x");
95 TestConflict("var x = 0", "const x");
96 TestConflict("var x", "const x = 0");
97 TestConflict("var x = 0", "const x = 0");
99 TestConflict("const x = undefined", "var x");
100 TestConflict("const x", "var x = undefined");
101 TestConflict("const x = undefined", "var x = undefined");
103 TestConflict("var x = undefined", "const x");
104 TestConflict("var x", "const x = undefined");
105 TestConflict("var x = undefined", "const x = undefined");
107 TestConflict("const x = undefined", "var x = 0");
108 TestConflict("const x = 0", "var x = undefined");
110 TestConflict("var x = undefined", "const x = 0");
111 TestConflict("var x = 0", "const x = undefined");
113 TestConflict("const x", "function x() { }");
114 TestConflict("const x = 0", "function x() { }");
115 TestConflict("const x = undefined", "function x() { }");
117 TestConflict("function x() { }", "const x");
118 TestConflict("function x() { }", "const x = 0");
119 TestConflict("function x() { }", "const x = undefined");
121 TestConflict("const x, y", "var x");
122 TestConflict("const x, y", "var y");
123 TestConflict("const x = 0, y", "var x");
124 TestConflict("const x = 0, y", "var y");
125 TestConflict("const x, y = 0", "var x");
126 TestConflict("const x, y = 0", "var y");
127 TestConflict("const x = 0, y = 0", "var x");
128 TestConflict("const x = 0, y = 0", "var y");
130 TestConflict("var x", "const x, y");
131 TestConflict("var y", "const x, y");
132 TestConflict("var x", "const x = 0, y");
133 TestConflict("var y", "const x = 0, y");
134 TestConflict("var x", "const x, y = 0");
135 TestConflict("var y", "const x, y = 0");
136 TestConflict("var x", "const x = 0, y = 0");
137 TestConflict("var y", "const x = 0, y = 0");
140 // Test that multiple conflicts do not cause issues.
141 TestConflict("var x, y", "const x, y");
144 // Test that repeated const declarations throw redeclaration errors.
145 TestConflict("const x", "const x");
146 TestConflict("const x = 0", "const x");
147 TestConflict("const x", "const x = 0");
148 TestConflict("const x = 0", "const x = 0");
150 TestConflict("const x = undefined", "const x");
151 TestConflict("const x", "const x = undefined");
152 TestConflict("const x = undefined", "const x = undefined");
154 TestConflict("const x = undefined", "const x = 0");
155 TestConflict("const x = 0", "const x = undefined");
157 TestConflict("const x, y", "const x");
158 TestConflict("const x, y", "const y");
159 TestConflict("const x = 0, y", "const x");
160 TestConflict("const x = 0, y", "const y");
161 TestConflict("const x, y = 0", "const x");
162 TestConflict("const x, y = 0", "const y");
163 TestConflict("const x = 0, y = 0", "const x");
164 TestConflict("const x = 0, y = 0", "const y");
166 TestConflict("const x", "const x, y");
167 TestConflict("const y", "const x, y");
168 TestConflict("const x", "const x = 0, y");
169 TestConflict("const y", "const x = 0, y");
170 TestConflict("const x", "const x, y = 0");
171 TestConflict("const y", "const x, y = 0");
172 TestConflict("const x", "const x = 0, y = 0");
173 TestConflict("const y", "const x = 0, y = 0");
176 // Test that multiple const conflicts do not cause issues.
177 TestConflict("const x, y", "const x, y");
180 // Test that const inside loop behaves correctly.
181 var loop = "for (var i = 0; i < 3; i++) { const x = i; }";
182 TestAll(0, loop, "x");
183 TestAll(0, "var a,b,c,d,e,f,g,h; " + loop, "x");
186 // Test that const inside with behaves correctly.
187 TestAll(87, "with ({x:42}) { const x = 87; }", "x");
188 TestAll(undefined, "with ({x:42}) { const x; }", "x");
191 // Additional tests for how various combinations of re-declarations affect
192 // the values of the var/const in question.
194 eval("var undefined;");
196 assertUnreachable("undefined (1) has thrown");
199 var original_undef = undefined;
200 var undefined = 1; // Should be silently ignored.
201 assertEquals(original_undef, undefined, "undefined got overwritten");
202 undefined = original_undef;
204 const e = 1; eval('var e = 2');
205 assertEquals(1, e, "e has wrong value");
207 const h; eval('var h = 1');
208 assertEquals(undefined, h, "h has wrong value");
210 eval("Object.defineProperty(this, 'i', { writable: true });"
212 + "assertEquals(7, i, \"i has wrong value\");");
215 Object.defineProperty(global, 'j', { value: 100, writable: true });
216 assertEquals(100, j);
217 // The const declaration stays configurable, so the declaration above goes
218 // through even though the const declaration is hoisted above.
220 assertEquals(2, j, "j has wrong value");
223 try { eval('const k'); } catch(e) { }
224 assertEquals(1, k, "k has wrong value");
225 try { eval('const k = 10'); } catch(e) { }
226 assertEquals(1, k, "k has wrong value");