What is stacktrace.js?

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 stacktrace.js?

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 available in IE or Safari 5-

var lastError;
try {
    // error producing code
} catch(e) {
   lastError = e;
   // do something else with error
}

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

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 stacktrace.js support?

It is currently tested and working on:

• Firefox (and Iceweasel) 0.9+
• Google Chrome 1+
• Safari 3.0+
• Opera 7+
• IE 5.5+
• Konqueror 3.5+
• Flock 1.0+
• SeaMonkey 1.0+
• K-Meleon 1.5.3+
• Epiphany 2.28.0+
• Iceape 1.1+

Contributions

This project is made possible due to the efforts of these fine people:

• Eric Wendelin
• Luke Smith
• Loic Dachary
• Johan Euphrosine
• Øyvind Sean Kinsey
• Victor Homyakov

Making contributions

When submitting your pull requests, please do the following to make it easier to incorporate your changes:

• Include unit and/or functional tests that validate changes you're making.
• Run unit tests in the latest IE, Firefox, Chrome, Safari and Opera and make sure they pass.
• Rebase your changes onto origin/HEAD if you can do so cleanly.
• If submitting additional functionality, provide an example of how to use it.
• Please keep code style consistent with surrounding code.

Testing

There are a few ways to run tests:

• You can run tests in PhantomJS by simply running gradlew test from your favorite shell.
• Run tests with JSTestDriver using gradlew jstd
• Point any browser to ≤project dir>/test/TestStacktrace.html for unit tests
• Point your browser to ≤project dir>/test/functional/index.html for more real-world functional tests