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 that we can set function prototypes to non-object values. The 29 // prototype used for instances in that case should be the initial 30 // object prototype. ECMA-262 13.2.2. 31 function TestNonObjectPrototype(value) { 32 function F() {}; 33 F.prototype = value; 34 var f = new F(); 35 assertEquals(value, F.prototype); 36 assertEquals(Object.prototype, f.__proto__); 37 // Test that map transitions don't break anything. 38 F.property = "value"; 39 assertEquals(value, F.prototype); 40 } 41 42 var values = [123, "asdf", true]; 43 44 values.forEach(TestNonObjectPrototype); 45 46 47 // Test moving between non-object and object values. 48 function F() {}; 49 var f = new F(); 50 assertEquals(f.__proto__, F.prototype); 51 F.prototype = 42; 52 f = new F(); 53 assertEquals(Object.prototype, f.__proto__); 54 assertEquals(42, F.prototype); 55 F.prototype = { a: 42 }; 56 f = new F(); 57 assertEquals(42, F.prototype.a); 58 assertEquals(f.__proto__, F.prototype); 59 60 61 // Test that the fast case optimizations can handle non-functions, 62 // functions with no prototypes (yet), non-object prototypes, 63 // functions without initial maps, and the fully initialized 64 // functions. 65 function GetPrototypeOf(f) { 66 return f.prototype; 67 }; 68 69 // Seed the GetPrototypeOf function to enable the fast case 70 // optimizations. 71 var p = GetPrototypeOf(GetPrototypeOf); 72 73 // Check that getting the prototype of a tagged integer works. 74 assertTrue(typeof GetPrototypeOf(1) == 'undefined'); 75 76 function NoPrototypeYet() { } 77 var p = GetPrototypeOf(NoPrototypeYet); 78 assertEquals(NoPrototypeYet.prototype, p); 79 80 function NonObjectPrototype() { } 81 NonObjectPrototype.prototype = 42; 82 assertEquals(42, GetPrototypeOf(NonObjectPrototype)); 83 84 function NoInitialMap() { } 85 var p = NoInitialMap.prototype; 86 assertEquals(p, GetPrototypeOf(NoInitialMap)); 87 88 // Check the standard fast case. 89 assertEquals(F.prototype, GetPrototypeOf(F)); 90 91 // Check that getting the prototype of a non-function works. This must 92 // be the last thing we do because this will clobber the optimizations 93 // in GetPrototypeOf and go to a monomorphic IC load instead. 94 assertEquals(87, GetPrototypeOf({prototype:87})); 95 96 // Check the prototype is not enumerable, as per ES5 section 15.3.5.2. Note 97 // that this is in difference to ES3, which specified that function instances 98 // would have enumerable prototypes (section 15.3.5.2 also). 99 var foo = new Function("return x"); 100 var result = "" 101 for (var n in foo) result += n; 102 assertEquals(result, ""); 103 104 f = new Function('return 1;') 105 var desc = Object.getOwnPropertyDescriptor(f, "prototype"); 106 assertFalse(desc.configurable); 107 assertFalse(desc.enumerable); 108 assertTrue(desc.writable); 109 110 f = Function('return 1;') 111 var desc = Object.getOwnPropertyDescriptor(f, "prototype"); 112 assertFalse(desc.configurable); 113 assertFalse(desc.enumerable); 114 assertTrue(desc.writable); 115 116 f = function () { return 1; } 117 var desc = Object.getOwnPropertyDescriptor(f, "prototype"); 118 assertFalse(desc.configurable); 119 assertFalse(desc.enumerable); 120 assertTrue(desc.writable); 121
