1 // Copyright 2011 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 temporal dead zone semantics of let bound variables in 29 // function and block scopes. 30 31 function TestFunctionLocal(s) { 32 try { 33 eval("(function(){" + s + "; })")(); 34 } catch (e) { 35 assertInstanceof(e, ReferenceError); 36 return; 37 } 38 assertUnreachable(); 39 } 40 41 function TestBlockLocal(s,e) { 42 try { 43 eval("(function(){ {" + s + ";} })")(); 44 } catch (e) { 45 assertInstanceof(e, ReferenceError); 46 return; 47 } 48 assertUnreachable(); 49 } 50 51 52 function TestAll(s) { 53 TestBlockLocal(s); 54 TestFunctionLocal(s); 55 } 56 57 // Use before initialization in declaration statement. 58 TestAll('let x = x + 1'); 59 TestAll('let x = x += 1'); 60 TestAll('let x = x++'); 61 TestAll('let x = ++x'); 62 TestAll('const x = x + 1'); 63 64 // Use before initialization in prior statement. 65 TestAll('x + 1; let x;'); 66 TestAll('x = 1; let x;'); 67 TestAll('x += 1; let x;'); 68 TestAll('++x; let x;'); 69 TestAll('x++; let x;'); 70 TestAll('let y = x; const x = 1;'); 71 TestAll('let y = x; class x {}'); 72 73 TestAll('f(); let x; function f() { return x + 1; }'); 74 TestAll('f(); let x; function f() { x = 1; }'); 75 TestAll('f(); let x; function f() { x += 1; }'); 76 TestAll('f(); let x; function f() { ++x; }'); 77 TestAll('f(); let x; function f() { x++; }'); 78 TestAll('f(); const x = 1; function f() { return x; }'); 79 TestAll('f(); class x { }; function f() { return x; }'); 80 81 TestAll('f()(); let x; function f() { return function() { return x + 1; } }'); 82 TestAll('f()(); let x; function f() { return function() { x = 1; } }'); 83 TestAll('f()(); let x; function f() { return function() { x += 1; } }'); 84 TestAll('f()(); let x; function f() { return function() { ++x; } }'); 85 TestAll('f()(); let x; function f() { return function() { x++; } }'); 86 TestAll('f()(); const x = 1; function f() { return function() { return x; } }'); 87 TestAll('f()(); class x { }; function f() { return function() { return x; } }'); 88 89 for (var kw of ['let x = 2', 'const x = 2', 'class x { }']) { 90 // Use before initialization with a dynamic lookup. 91 TestAll(`eval("x"); ${kw};`); 92 TestAll(`eval("x + 1;"); ${kw};`); 93 TestAll(`eval("x = 1;"); ${kw};`); 94 TestAll(`eval("x += 1;"); ${kw};`); 95 TestAll(`eval("++x;"); ${kw};`); 96 TestAll(`eval("x++;"); ${kw};`); 97 98 // Use before initialization with check for eval-shadowed bindings. 99 TestAll(`function f() { eval("var y = 2;"); x + 1; }; f(); ${kw};`); 100 TestAll(`function f() { eval("var y = 2;"); x = 1; }; f(); ${kw};`); 101 TestAll(`function f() { eval("var y = 2;"); x += 1; }; f(); ${kw};`); 102 TestAll(`function f() { eval("var y = 2;"); ++x; }; f(); ${kw};`); 103 TestAll(`function f() { eval("var y = 2;"); x++; }; f(); ${kw};`); 104 } 105 106 // Test that variables introduced by function declarations are created and 107 // initialized upon entering a function / block scope. 108 function f() { 109 { 110 assertEquals(2, g1()); 111 assertEquals(2, eval("g1()")); 112 113 // block scoped function declaration 114 function g1() { 115 return 2; 116 } 117 } 118 119 assertEquals(3, g2()); 120 assertEquals(3, eval("g2()")); 121 // function scoped function declaration 122 function g2() { 123 return 3; 124 } 125 } 126 f(); 127 128 // Test that a function declaration introduces a block scoped variable 129 // and no function hoisting if there is a conflict. 130 TestFunctionLocal('{ function k() { return 0; } }; k(); let k;'); 131 132 // Test that a function declaration sees the scope it resides in. 133 function f2() { 134 let m, n, o, p; 135 { 136 m = g; 137 function g() { 138 return a; 139 } 140 let a = 1; 141 } 142 assertEquals(1, m()); 143 144 try { 145 throw 2; 146 } catch(b) { 147 n = h; 148 function h() { 149 return b + c; 150 } 151 let c = 3; 152 } 153 assertEquals(5, n()); 154 155 { 156 o = i; 157 function i() { 158 return d; 159 } 160 let d = 4; 161 } 162 assertEquals(4, o()); 163 164 try { 165 throw 5; 166 } catch(e) { 167 p = j; 168 function j() { 169 return e + f; 170 } 171 let f = 6; 172 } 173 assertEquals(11, p()); 174 } 175 f2(); 176 177 // Test that resolution of let bound variables works with scopes that call eval. 178 function outer() { 179 function middle() { 180 function inner() { 181 return x; 182 } 183 eval("1 + 1"); 184 return x + inner(); 185 } 186 187 let x = 1; 188 return middle(); 189 } 190 191 assertEquals(2, outer()); 192
