What is Javascript Stacktrace?

A Javascript tool that allows you to debug your Javascript by giving you a stack trace of function calls leading to an error (or any condition you specify)

How do I use Javascript Stacktrace?

Just include stacktrace.js file on your page, and call it like so:

<script type="text/javascript" src="path/to/stacktrace.js" />
<script type="text/javascript">
    ... your code ...
    if (errorCondition) {
         var trace = printStackTrace();
         //Output however you want!
         alert(trace.join('\n\n'));
    }
    ... more code of yours ...
</script>

Bookmarklet available on the project home page.

You can also pass in your own Error to get a stacktrace not in IE or Safari, though :(

<script type="text/javascript">
	var lastError;
	try {
	    // error producing code
	} catch(e) {
	   lastError = e;
	   // do something else with error
	}

	// Returns stacktrace from lastError!
	printStackTrace({e: lastError});
</script>

Some people recommend just assigning it to window.onerror Only in IE and FF

window.onerror = function(msg, file, line) {
    alert(printStackTrace().join('\n\n'));
}

Function Instrumentation

You can now have any (public or privileged) function give you a stacktrace when it is called:

var p = new printStackTrace.implementation();
p.instrumentFunction(this, 'baz', logStackTrace);
function logStackTrace(stack) {
	console.log(stack.join('\n'));
}
function foo() {
	var a = 1;
	bar();
}
function bar() {
	baz();
}
foo(); //Will log a stacktrace when 'baz()' is called containing 'foo()'!

p.deinstrumentFunction(this, 'baz'); //Remove function instrumentation

What browsers does Javascript Stacktrace support?

It is currently tested and working on:

• Firefox (and Iceweasel) 0.9+
• Google Chrome 1+
• Safari 3.0+
• IE 5.5+
• Konqueror 3.5+
• Flock 1.0+
• SeaMonkey 1.0+
• K-Meleon 1.5.3+
• Epiphany 2.28.0+
• Iceape 1.1+

Working (readable, valid stack trace) but not perfectly tested on:

• Opera 7+