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"use strict"; 29 30// Test temporal dead zone semantics of let bound variables in 31// function and block scopes. 32 33function TestFunctionLocal(s) { 34 try { 35 eval("(function(){" + s + "; })")(); 36 } catch (e) { 37 assertInstanceof(e, ReferenceError); 38 return; 39 } 40 assertUnreachable(); 41} 42 43function TestBlockLocal(s,e) { 44 try { 45 eval("(function(){ {" + s + ";} })")(); 46 } catch (e) { 47 assertInstanceof(e, ReferenceError); 48 return; 49 } 50 assertUnreachable(); 51} 52 53 54function TestAll(s) { 55 TestBlockLocal(s); 56 TestFunctionLocal(s); 57} 58 59// Use before initialization in declaration statement. 60TestAll('let x = x + 1'); 61TestAll('let x = x += 1'); 62TestAll('let x = x++'); 63TestAll('let x = ++x'); 64TestAll('const x = x + 1'); 65 66// Use before initialization in prior statement. 67TestAll('x + 1; let x;'); 68TestAll('x = 1; let x;'); 69TestAll('x += 1; let x;'); 70TestAll('++x; let x;'); 71TestAll('x++; let x;'); 72TestAll('let y = x; const x = 1;'); 73TestAll('let y = x; class x {}'); 74 75TestAll('f(); let x; function f() { return x + 1; }'); 76TestAll('f(); let x; function f() { x = 1; }'); 77TestAll('f(); let x; function f() { x += 1; }'); 78TestAll('f(); let x; function f() { ++x; }'); 79TestAll('f(); let x; function f() { x++; }'); 80TestAll('f(); const x = 1; function f() { return x; }'); 81TestAll('f(); class x { }; function f() { return x; }'); 82 83TestAll('f()(); let x; function f() { return function() { return x + 1; } }'); 84TestAll('f()(); let x; function f() { return function() { x = 1; } }'); 85TestAll('f()(); let x; function f() { return function() { x += 1; } }'); 86TestAll('f()(); let x; function f() { return function() { ++x; } }'); 87TestAll('f()(); let x; function f() { return function() { x++; } }'); 88TestAll('f()(); const x = 1; function f() { return function() { return x; } }'); 89TestAll('f()(); class x { }; function f() { return function() { return x; } }'); 90 91for (var kw of ['let x = 2', 'const x = 2', 'class x { }']) { 92 // Use before initialization with a dynamic lookup. 93 TestAll(`eval("x"); ${kw};`); 94 TestAll(`eval("x + 1;"); ${kw};`); 95 TestAll(`eval("x = 1;"); ${kw};`); 96 TestAll(`eval("x += 1;"); ${kw};`); 97 TestAll(`eval("++x;"); ${kw};`); 98 TestAll(`eval("x++;"); ${kw};`); 99 100 // Use before initialization with check for eval-shadowed bindings. 101 TestAll(`function f() { eval("var y = 2;"); x + 1; }; f(); ${kw};`); 102 TestAll(`function f() { eval("var y = 2;"); x = 1; }; f(); ${kw};`); 103 TestAll(`function f() { eval("var y = 2;"); x += 1; }; f(); ${kw};`); 104 TestAll(`function f() { eval("var y = 2;"); ++x; }; f(); ${kw};`); 105 TestAll(`function f() { eval("var y = 2;"); x++; }; f(); ${kw};`); 106} 107 108// Test that variables introduced by function declarations are created and 109// initialized upon entering a function / block scope. 110function f() { 111 { 112 assertEquals(2, g1()); 113 assertEquals(2, eval("g1()")); 114 115 // block scoped function declaration 116 function g1() { 117 return 2; 118 } 119 } 120 121 assertEquals(3, g2()); 122 assertEquals(3, eval("g2()")); 123 // function scoped function declaration 124 function g2() { 125 return 3; 126 } 127} 128f(); 129 130// Test that a function declaration introduces a block scoped variable. 131TestAll('{ function k() { return 0; } }; k(); '); 132 133// Test that a function declaration sees the scope it resides in. 134function f2() { 135 let m, n, o, p; 136 { 137 m = g; 138 function g() { 139 return a; 140 } 141 let a = 1; 142 } 143 assertEquals(1, m()); 144 145 try { 146 throw 2; 147 } catch(b) { 148 n = h; 149 function h() { 150 return b + c; 151 } 152 let c = 3; 153 } 154 assertEquals(5, n()); 155 156 { 157 o = i; 158 function i() { 159 return d; 160 } 161 let d = 4; 162 } 163 assertEquals(4, o()); 164 165 try { 166 throw 5; 167 } catch(e) { 168 p = j; 169 function j() { 170 return e + f; 171 } 172 let f = 6; 173 } 174 assertEquals(11, p()); 175} 176f2(); 177 178// Test that resolution of let bound variables works with scopes that call eval. 179function outer() { 180 function middle() { 181 function inner() { 182 return x; 183 } 184 eval("1 + 1"); 185 return x + inner(); 186 } 187 188 let x = 1; 189 return middle(); 190} 191 192assertEquals(2, outer()); 193