Develop Reference

debugging javascript console error

I just got some big project and with error in console. there are many more than scripts used at that page but error shows very little information. there are 25 scripts loading at page. To give you an idea how many scripts they are you can see. :(
I have error in console but i can't find which original file, line number causing it. the error showing are in library. but i know it's not library bug it's caused by some other script. but this stack trace is very small. is there any tool or any other way where i can originally find from where it is originating.
let me know if further information is required.

If you click on link "amstock.js" you will be redirect to that file and directly in the line that was causing the error. Always the upper file is which causes the problem, but some times because of a previous one.
In adition, the error maybe cause by an asynchronous call that leaves your variable in null and fill it after the line of the error was call, or just you are trying to access a wrong variable. Check that line.

Uncaught TypeError without ability to find the reason

Every time I right-click anywhere in my Application, jQuery is going to throw an error at line 5095 saying:
Uncaught TypeError: undefined is not a function
To find the cause of this error I tried two ways without success:
1. Debug jQuery:
In the Dev-Tool's I debug jQuery at Line 5095. The Problem: When I move the cursor over the page, it will stop and break. I have NO possibility to get it to make a right click. Even if I press play in Chrome's Debug-Line which appears, it will instantly fire again, even if I won't move the cursor!
2. Searching the reason in my code:
Since this Error is thrown for a long time now I cannot tell where to search. I have multiple js-files. So I realized the error is being thrown when I release the mouse-button. So I searched ALL my code for ANY mouse(-up/down)-events without success (found several that wont fire if I set breakpoints)
Now I am out of ideas how to find the source of it. I thought debugging the line of jQuery where the error is thrown would give me access to the stack variables with possibly more information about its source. Any suggestions?
Please don't ask me to post code. Since I can't tell where the mistakes happen I might post thousands of lines of JavaScript. I need a logical way to find the Errorsource.

the error definitely isn't in jquery or jquery-ui files. it's most definitely in a plugin's code or your custom code.
think of where the error might be. just do a basic estimation. and put a console.log() before those lines and run it again. see if the error occurs before the console output. if it happens before, investigate the code that executes before this line and the javascript files that are included before this file. if it happens after do the opposite. You can narrow down by putting multiple console.log()s

you can look at events with
$._data(element, "events")
but you cant see where the bind is in your code
maybe someone knows

"Object doesn't support property or method 'getAttribute'"

I'm working with Dynamics CRM 2011 Online and trying to refactor some code that works on the Quote > Add Product page to also work on Order > Add Product. The problem is that when the page loads I get the error "Unable to get property 'getValue' of undefined or null reference."
I went into the IE console (tried both IE 9 and 10) and typed in what I believed to be the offending line:
Xrm.Page.getAttribute('ati_clin').getValue()
It complains with "Object doesn't support property or method 'getAttribute'". I also tried
document.getElementById('ati_clin')
but that too fails.
This doesn't make sense to me because I can use the HTML view of the developer console to find the object on the page and it's clearly there (no typo too). It also doesn't make sense that this statement fails in the console on both pages even though one of the pages runs properly at runtime and the other doesn't. Shouldn't it at least work on the page that does work at runtime?
After doing some research I think the following posting is the most relevant but I'm afraid it doesn't lead me to an answer seeing as how new I am to this: Xrm.Page.data is null
My question is why does the console return this error if the element clearly exists?

A handy trick when debugging a problem like this:
The Xrm.Page object lives in the context of a frame. If you want to use console in IE Developer tools without having to break in debug mode, you first have to point to the frame on the page.
Example:
frames[0].Xrm.Page.getAttribute('ati_clin').getValue()

Stop suppressing JavaScript errors

I'm using Firebug to view JavaScript errors. But I'm also using jQuery. For some reason, I never see JavaScript errors when using jQuery and this is one of the biggest problems with working with jQuery in the first place.
There's no particular code to show, just imagine alert(areareg); where areareg is undefined or any sort of JavaScript error, and Firebug won't tell me about it. The JavaScript will simply fail without warning or notification of any sort. This is always the case, in any project where I've used jQuery and it's the only reason I don't like jQuery; because it's notoriously difficult to debug when something goes wrong.
For some reason I've even had trouble finding this question raised online, let alone answered. But I figured I'd give it a try here:
Is there any way to make jQuery stop suppressing error messages?
Am I the only one in the world who has always had this problem with jQuery?
EDIT:
I use both Firefox (with Firebug) and Chrome, and I only use the non-minified version of jQuery. Still, I have never in my entire life seen a jQuery error message of any kind, neither useful nor useless, nor in fact normal JavaScript errors, when using jQuery.

Well, despite your impression, jQuery itself doesn't do anything to "suppress" error messages. Now, Firefox does tend to throw away certain kinds of exceptions, notably like what you describe. I often find that wrapping a whole Javascript block in a try ... catch with an alert call should an exception happen is a useful way to deal with it, but it's still irritating.

I use google Chrome for my debugging, and it's pretty good, it shows all the jquery errors as well (as Alfred said, if you use minified version, you wont get any meaningful name in your errors, so it's better to use the raw source)

I am having the same problem in FF 18. I am using JSF and JQuery, though it happens even for plain JS code on the page. I intentionally put javascript code that should throw a syntax error without a word in Firebug. FF 18 has its own built-in console that looks similar to firebug. When I disabled the firebug plug-in the console.log messages started showing up. However, the errors are still not showing up. I just tried Chrome and the errors do appear there.

I've run into this problem several times. It's quite inconsistent and hard to replicate, sometimes it seems related to version issues. Settings rarely seem to make a difference, though "Break on next" sometimes (not always) identifies errors that otherwise slip through.
One thing I've noticed is, it tends to happen for code that is triggered inside a callback function, e.g. from a UI event or from an AJAX call. Sometimes Firefox / Firebug will behave like other browsers and show errors in the console, sometimes it gives nothing at all even for incredibly clear-cut cases like:
console.log('something'); // Shows up in console fine
fail // Other browsers give undefined variable error, Firefox gives nothing
console.log('something else'); // Never reached, so silent error clearly happens
The best approach I've found to this is:
Once you've found a no-show error, work back using console.trace() until you reach a point where inside a function, the error is hidden, outside, it shows, adding some code snippet like:
console.trace();
fail // cause the error, look out for a trace followed by nothing
If it's an AJAX call, manually add a basic error handler, because for some reason Firefox/Firebug is losing the default:
$.ajax({
error: function(a,b,c){
throw c;
},
other: '...settings'
}
If it's something you can't add an error handling function to, wrap it in a try... catch, for example:
try {
// whatever the code is within which there are no errors
} catch( err ){
throw err;
}
This should be enough to catch all errors where-ever they are within the scope where Firefox is losing them. Beware of cases where you have a callback within a callback though, you might need to do this twice...

'Invalid Argument' Error in IE, in a line number that doesn't exist

I'm getting the following error in IE 6:
Line: 454
Char: 13
Error: Invalid Argument
Code: 0
URL: xxxxx/Iframe1.aspx
and I can't for the life of me find what's causing this.
This only happens in a situation where I have a main page that has several IFrames, and it only happens when I have one particular IFrame (the one pointed to by the URL in the error message), and that IFrame is invisible at the time of loading.
I've narrowed it up to there, but I still can't find anything more specific...
The IFrame in question doesn't have 454 lines in its HTML, nor do any of the JS files referred by it.
I tried attaching VS to iexplore.exe as a debugger, and it breaks when the error occurs, but then tells me "There is no source code available for the current location"...
Any suggestions on how I can go about chasing this one?
UPDATE: I found this problem through brute-force, basically, commenting everything out and uncommenting randomly...
But the question still stands: what is the rational way to find where the error is, when IE reports the wrong line number / file?

IE's Javascript engine is disgusting when it comes to debugging. You can try enabling script debugging in the Advanced Options, and then if you have Visual Studio installed it will jump to the place of error... if you're lucky. Other times you don't get anything, especially if the code was eval()'ed.
Another thing about these line numbers is that it doesn't reflect which file the error is happening in. I've had cases where the line number was actually correct, but it was in a linked .js file, not the main file.

Try using the Microsoft Script Debugger or DebugBar (http://www.debugbar.com) which may give you some better IE6 debugging tools. They always help me with IE6.
Also, does this happen in any newer versions of IE or just in IE6?

It's virtually impossible to debug this without a live example, but one thing that often causes an "Invalid Argument" error in Internet Explorer is trying to set an incorrect value for a style property.
So something like:
document.getElementById("foo").style.borderWidth = bar + "px";
when "bar" has the value null, or undefined, or is the string "grandma", will cause it, as "grandmapx" isn't a valid value for the borderWidth style property.

IE9 has a browser mode.
Open up Developer Tools, then select the version you want to emulate in the console, reload the page with errors, and the console will show you line numbers and the correct file where the error is.

I run into this problem a lot too, and I've also resorted to commenting everything out until I find the problem. One thing that I find to be useful is to add a try/catch block to every javascript method. Sometimes I add an alert to tell what method the error came from. Still tedious, but easier than trial and error commenting. And if you add them every time you write a new method it saves a lot of time in the event errors like those occur.
function TestMethod()
{
try
{
//whatever
}
catch (ex)
{
ShowError(ex.description);
//alert("TestMethod");
}
}

A note to other readers: I recently had this "Invalid argument." error reported in IE7-9 and eventually found that it was down to the way I was using setTimeout/setInterval.
This is wrong, in IE:
var Thing = {};
Thing.myFunc = function() { ... };
setTimeout(Thing.myFunc, 1000);
Instead, wrap the callback in an anonymous function like so:
var Thing = {};
Thing.myFunc = function() { ... };
setTimeout(function() { Thing.myFunc(); }, 1000);
and no more "invalid argument" errors.

Another possibility:
I do a lot of dev between two computers, at home and at work, so I often email myself or download pages from the server to work on. Recently I realised that Vista has a habit of unilaterally applying blocks to certain files when they are downloaded in certain ways, without notifying me that it is doing this.
The result is that, for example, an HTML page wants to access the .js file in its header, but it doesn't have permission to access local files. In this case, it doesn't matter what you write in the .js file, the browser will never even read it, and an irksome Line: 0 error will result.
So before you comb your code for an error, check your HTML page's properties, and see if it hasn't been blocked by the OS....

Like NickFitz pointed out, styling was an issue with my code.
document.getElementById('sums<%= event.id %>').style.border='1px solid #3b3b3b;'
I removed the border style and my IE issues were gone.