michael@0: /* vim:set ts=2 sw=2 sts=2 ci et: */
michael@0: /* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: 
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: // This file contains functions that are useful for debugging purposes from
michael@0: // within JavaScript code.
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = ["NS_ASSERT"];
michael@0: 
michael@0: var gTraceOnAssert = true;
michael@0: 
michael@0: /**
michael@0:  * This function provides a simple assertion function for JavaScript.
michael@0:  * If the condition is true, this function will do nothing.  If the
michael@0:  * condition is false, then the message will be printed to the console
michael@0:  * and an alert will appear showing a stack trace, so that the (alpha
michael@0:  * or nightly) user can file a bug containing it.  For future enhancements, 
michael@0:  * see bugs 330077 and 330078.
michael@0:  *
michael@0:  * To suppress the dialogs, you can run with the environment variable
michael@0:  * XUL_ASSERT_PROMPT set to 0 (if unset, this defaults to 1).
michael@0:  *
michael@0:  * @param condition represents the condition that we're asserting to be
michael@0:  *                  true when we call this function--should be
michael@0:  *                  something that can be evaluated as a boolean.
michael@0:  * @param message   a string to be displayed upon failure of the assertion
michael@0:  */
michael@0: 
michael@0: this.NS_ASSERT = function NS_ASSERT(condition, message) {
michael@0:   if (condition)
michael@0:     return;
michael@0: 
michael@0:   var releaseBuild = true;
michael@0:   var defB = Components.classes["@mozilla.org/preferences-service;1"]
michael@0:                        .getService(Components.interfaces.nsIPrefService)
michael@0:                        .getDefaultBranch(null);
michael@0:   try {
michael@0:     switch (defB.getCharPref("app.update.channel")) {
michael@0:       case "nightly":
michael@0:       case "aurora":
michael@0:       case "alpha":
michael@0:       case "beta":
michael@0:       case "default":
michael@0:         releaseBuild = false;
michael@0:     }
michael@0:   } catch(ex) {}
michael@0: 
michael@0:   var caller = arguments.callee.caller;
michael@0:   var assertionText = "ASSERT: " + message + "\n";
michael@0: 
michael@0:   // Report the error to the console
michael@0:   Components.utils.reportError(assertionText);
michael@0: 
michael@0:   if (releaseBuild) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   // dump the stack to stdout too in non-release builds
michael@0:   var stackText = "";
michael@0:   if (gTraceOnAssert) {
michael@0:     stackText = "Stack Trace: \n";
michael@0:     var count = 0;
michael@0:     while (caller) {
michael@0:       stackText += count++ + ":" + caller.name + "(";
michael@0:       for (var i = 0; i < caller.arguments.length; ++i) {
michael@0:         var arg = caller.arguments[i];
michael@0:         stackText += arg;
michael@0:         if (i < caller.arguments.length - 1)
michael@0:           stackText += ",";
michael@0:       }
michael@0:       stackText += ")\n";
michael@0:       caller = caller.arguments.callee.caller;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   dump(assertionText + stackText);
michael@0: }