JezK
Edit File: object-toprimitive.js
// Copyright 2010 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. // Test the ToPrimitive internal function used by ToNumber/ToString. // Does it [[Get]] and [[Call]] the object's toString and valueOf properties // correctly. Specifically, does it call [[Get]] only once per property. var o1 = { toString: function() { return 42; }, valueOf: function() { return "37"; } }; var n1 = Number(o1); var s1 = String(o1); assertTrue(typeof n1 == "number"); assertTrue(typeof s1 == "string"); var trace = []; var valueOfValue = 42; var toStringValue = "foo"; function traceValueOf () { trace.push("vo"); return valueOfValue; }; function traceToString() { trace.push("ts"); return toStringValue; }; var valueOfFunc = traceValueOf; var toStringFunc = traceToString; var ot = { get toString() { trace.push("gts"); return toStringFunc; }, get valueOf() { trace.push("gvo"); return valueOfFunc; } }; var nt = Number(ot); assertEquals(42, nt); assertEquals(["gvo","vo"], trace); trace = []; var st = String(ot); assertEquals("foo", st); assertEquals(["gts","ts"], trace); trace = []; valueOfValue = ["not primitive"]; var nt = Number(ot); assertEquals(Number("foo"), nt); assertEquals(["gvo", "vo", "gts", "ts"], trace); trace = []; valueOfValue = 42; toStringValue = ["not primitive"]; var st = String(ot); assertEquals(String(42), st); assertEquals(["gts", "ts", "gvo", "vo"], trace); trace = []; valueOfValue = ["not primitive"]; assertThrows("Number(ot)", TypeError); assertEquals(["gvo", "vo", "gts", "ts"], trace); toStringFunc = "not callable"; trace = []; valueOfValue = 42; var st = String(ot); assertEquals(String(42), st); assertEquals(["gts", "gvo", "vo"], trace); valueOfFunc = "not callable"; trace = []; assertThrows("String(ot)", TypeError); assertEquals(["gts", "gvo"], trace); toStringFunc = traceToString; toStringValue = "87"; trace = []; var nt = Number(ot); assertEquals(87, nt); assertEquals(["gvo", "gts", "ts"], trace);