Question

I’m using window.onerror, and window.onbeforeunload to pass all the errors encountered in the users session with AJAX, I’m trying to test it, and I need to create some javascript errors to test if it is catching it I’ve tried things like var a = b; (where b doesn’t exist) problem is these errors seems to be fatal and stop any further processing…

Can anyone think of a decent way to cause some errors without stopping the processing of the script?

ErrorManager: (function () {
        function Init(message) {
            InitErrorHandler();
            InitAjaxHandler();


        }
        function InitErrorHandler() {
            Data.ErrorHandlerText = "";
            Data.ErrorHandlerCount = 0;
            window.onerror = function(errorMessage, url, line) {
                Data.ErrorHandlerText +"Error: "+(Data.ErrorHandlerCount+1)+" \n\n";
                //Get error specific info
                Data.ErrorHandlerText += escape(errorMessage) + "\n";
                Data.ErrorHandlerText +=  escape(url) + "\n";
                Data.ErrorHandlerText +=  escape(line) + "\n";
                Data.ErrorHandlerCount++;
            }
        }
        function InitAjaxHandler() {
            window.onbeforeunload = function() { //when browser closed
                if(Data.ErrorHandlerCount > 0) {
                    SendErrorsToAjax();
                }
            }
        }
        function SendErrorsToAjax() {
            PrepareErrorsForAjax();
            $.getJSON(Interface.PrefixUrl('/sendjserrors/'+Data.ErrorHandlerText), AjaxCallback);
        }
        function AjaxCallback(response) {
            console.log('response of js error ajax request '+response);
        }
        function PrepareErrorsForAjax() {
            var preText = "A user has encountered a few errors: \n\n";
            //Get session info
            var userAgent, activePageID;
            userAgent = escape(navigator.userAgent);
            preText += "User agent: "+userAgent+" \n";
            if($.mobile.activePage != null) {
                activePageID = $.mobile.activePage.attr('id');
                preText += "Page ID: "+activePageID+" \n";
            }

            preText += "\n The following errors were encountered:\n\n";
            Data.ErrorHandlerText = preText + Data.ErrorHandlerText;
        }
        return {
            Init: Init,
            SendErrorsToAjax: SendErrorsToAjax
        }
    })(),

Answer 1

How about

throw new Error( 'No worries. Just testing...' );

You do have to catch it though if you don’t want your program to break.