JezK
Edit File: arguments-read-and-assignment.js
// Copyright 2009 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. // Testing basic functionality of the arguments object. // Introduced to ensure that the fast compiler does the right thing. // The arguments object itself. assertEquals(42, function(){ return arguments;}(42)[0], "return arguments value"); assertEquals(42, function(){ return arguments;}(42)[0], "arguments in plain value context"); assertEquals(42, function(){ arguments;return 42}(37), "arguments in effect context"); assertEquals(42, function(){ if(arguments)return 42;}(), "arguments in a boolean context"); assertEquals(42, function(){ return arguments || true;}(42)[0], "arguments in a short-circuit boolean context - or"); assertEquals(true, function(){ return arguments && [true];}(42)[0], "arguments in a short-circuit boolean context - and"); assertEquals(42, function(){ arguments = 42; return 42;}(), "arguments assignment"); // Properties of the arguments object. assertEquals(42, function(){ return arguments[0]; }(42), "args[0] value returned"); assertEquals(42, function(){ arguments[0]; return 42}(), "args[0] value ignored"); assertEquals(42, function(){ if (arguments[0]) return 42; }(37), "args[0] to boolean"); assertEquals(42, function(){ return arguments[0] || "no"; }(42), "args[0] short-circuit boolean or true"); assertEquals(42, function(){ return arguments[0] || 42; }(0), "args[0] short-circuit boolean or false"); assertEquals(37, function(){ return arguments[0] && 37; }(42), "args[0] short-circuit boolean and true"); assertEquals(0, function(){ return arguments[0] && 42; }(0), "args[0] short-circuit boolean and false"); assertEquals(42, function(){ arguments[0] = 42; return arguments[0]; }(37), "args[0] assignment"); // Link between arguments and parameters. assertEquals(42, function(a) { arguments[0] = 42; return a; }(37), "assign args[0]->a"); assertEquals(42, function(a) { a = 42; return arguments[0]; }(37), "assign a->args[0]"); assertEquals(54, function(a, b) { arguments[1] = 54; return b; }(42, 37), "assign args[1]->b:b"); assertEquals(54, function(a, b) { b = 54; return arguments[1]; }(42, 47), "assign b->args[1]:b"); assertEquals(42, function(a, b) { arguments[1] = 54; return a; }(42, 37), "assign args[1]->b:a"); assertEquals(42, function(a, b) { b = 54; return arguments[0]; }(42, 47), "assign b->args[1]:a"); // Capture parameters in nested contexts. assertEquals(33, function(a,b) { return a + arguments[0] + function(b){ return a + b + arguments[0]; }(b); }(7,6), "captured parameters"); assertEquals(42, function(a) { arguments[0] = 42; return function(b){ return a; }(); }(37), "capture value returned"); assertEquals(42, function(a) { arguments[0] = 26; return function(b){ a; return 42; }(); }(37), "capture value ignored"); assertEquals(42, function(a) { arguments[0] = 26; return function(b){ if (a) return 42; }(); }(37), "capture to boolean"); assertEquals(42, function(a) { arguments[0] = 42; return function(b){ return a || "no"; }(); }(37), "capture short-circuit boolean or true"); assertEquals(0, function(a) { arguments[0] = 0; return function(b){ return a && 42; }(); }(37), "capture short-circuit boolean and false"); // Deeply nested. assertEquals(42, function(a,b) { return arguments[2] + function(){ return b + function() { return a; }(); }(); }(7,14,21), "deep nested capture"); // Assignment to captured parameters. assertEquals(42, function(a,b) { arguments[1] = 11; return a + function(){ a = b; return a; }() + a; }(20, 37), "captured assignment"); // Inside non-function scopes. assertEquals(42, function(a) { arguments[0] = 20; with ({ b : 22 }) { return a + b; } }(37), "a in with"); assertEquals(42, function(a) { with ({ b : 22 }) { return arguments[0] + b; } }(20), "args in with"); assertEquals(42, function(a) { arguments[0] = 20; with ({ b : 22 }) { return function() { return a; }() + b; } }(37), "captured a in with"); assertEquals(42, function(a) { arguments[0] = 12; with ({ b : 22 }) { return function f() { try { throw 8 } catch(e) { return e + a }; }() + b; } }(37), "in a catch in a named function captured a in with "); // Escaping arguments. function weirdargs(a,b,c) { if (!a) return arguments; return [b[2],c]; } var args1 = weirdargs(false, null, 40); var res = weirdargs(true, args1, 15); assertEquals(40, res[0], "return old args element"); assertEquals(15, res[1], "return own args element");