// Copyright 2011 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following // disclaimer in the documentation and/or other materials provided // with the distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. "use strict"; // Test temporal dead zone semantics of let bound variables in // function and block scopes. function TestFunctionLocal(s) { try { eval("(function(){" + s + "; })")(); } catch (e) { assertInstanceof(e, ReferenceError); return; } assertUnreachable(); } function TestBlockLocal(s,e) { try { eval("(function(){ {" + s + ";} })")(); } catch (e) { assertInstanceof(e, ReferenceError); return; } assertUnreachable(); } function TestAll(s) { TestBlockLocal(s); TestFunctionLocal(s); } // Use before initialization in declaration statement. TestAll('let x = x + 1'); TestAll('let x = x += 1'); TestAll('let x = x++'); TestAll('let x = ++x'); TestAll('const x = x + 1'); // Use before initialization in prior statement. TestAll('x + 1; let x;'); TestAll('x = 1; let x;'); TestAll('x += 1; let x;'); TestAll('++x; let x;'); TestAll('x++; let x;'); TestAll('let y = x; const x = 1;'); TestAll('let y = x; class x {}'); TestAll('f(); let x; function f() { return x + 1; }'); TestAll('f(); let x; function f() { x = 1; }'); TestAll('f(); let x; function f() { x += 1; }'); TestAll('f(); let x; function f() { ++x; }'); TestAll('f(); let x; function f() { x++; }'); TestAll('f(); const x = 1; function f() { return x; }'); TestAll('f(); class x { }; function f() { return x; }'); TestAll('f()(); let x; function f() { return function() { return x + 1; } }'); TestAll('f()(); let x; function f() { return function() { x = 1; } }'); TestAll('f()(); let x; function f() { return function() { x += 1; } }'); TestAll('f()(); let x; function f() { return function() { ++x; } }'); TestAll('f()(); let x; function f() { return function() { x++; } }'); TestAll('f()(); const x = 1; function f() { return function() { return x; } }'); TestAll('f()(); class x { }; function f() { return function() { return x; } }'); for (var kw of ['let x = 2', 'const x = 2', 'class x { }']) { // Use before initialization with a dynamic lookup. TestAll(`eval("x"); ${kw};`); TestAll(`eval("x + 1;"); ${kw};`); TestAll(`eval("x = 1;"); ${kw};`); TestAll(`eval("x += 1;"); ${kw};`); TestAll(`eval("++x;"); ${kw};`); TestAll(`eval("x++;"); ${kw};`); // Use before initialization with check for eval-shadowed bindings. TestAll(`function f() { eval("var y = 2;"); x + 1; }; f(); ${kw};`); TestAll(`function f() { eval("var y = 2;"); x = 1; }; f(); ${kw};`); TestAll(`function f() { eval("var y = 2;"); x += 1; }; f(); ${kw};`); TestAll(`function f() { eval("var y = 2;"); ++x; }; f(); ${kw};`); TestAll(`function f() { eval("var y = 2;"); x++; }; f(); ${kw};`); } // Test that variables introduced by function declarations are created and // initialized upon entering a function / block scope. function f() { { assertEquals(2, g1()); assertEquals(2, eval("g1()")); // block scoped function declaration function g1() { return 2; } } assertEquals(3, g2()); assertEquals(3, eval("g2()")); // function scoped function declaration function g2() { return 3; } } f(); // Test that a function declaration introduces a block scoped variable. TestAll('{ function k() { return 0; } }; k(); '); // Test that a function declaration sees the scope it resides in. function f2() { let m, n, o, p; { m = g; function g() { return a; } let a = 1; } assertEquals(1, m()); try { throw 2; } catch(b) { n = h; function h() { return b + c; } let c = 3; } assertEquals(5, n()); { o = i; function i() { return d; } let d = 4; } assertEquals(4, o()); try { throw 5; } catch(e) { p = j; function j() { return e + f; } let f = 6; } assertEquals(11, p()); } f2(); // Test that resolution of let bound variables works with scopes that call eval. function outer() { function middle() { function inner() { return x; } eval("1 + 1"); return x + inner(); } let x = 1; return middle(); } assertEquals(2, outer());