Perfect.js

PERF ormance E valuating C omparative T esting

Perfect is a library that works in conjunction with Benchmarkjs.

Goals

Perfect helps you spot performance regressions in your code by running benchmarks on multiple versions of your library.

Usage

The minimal working code you need to use Perfect resembles this:

var perfect = new Perfect({
	a: "lib/target_library_0.1.js",
	b: "lib/target_library_0.2.js"
});

perfect.add("some test", function() {
	target_library.some_function();
});

perfect.run();

As you can see, Perfect expects paths to two versions of the library you need to test for performance regressions, and they go to properties a and b.

The in-built UI

Perfect ships with a very simple UI. To enable it, pass the following option to the constructor:

	enable_ui: true

You will need an HTML file that includes the Perfect CSS file:

<link rel="stylesheet" type="text/css" href="perfect-ui.min.css" />

and the following JavaScript files:

<script src="perfect-libs.js"></script>
<script src="perfect-ui.js"></script>
<script src="perfect.js"></script>

Additionally, you need an element with id="pefect". Please see the "simple" example.

QUnit compatibility layer

Because Perfect works by comparing two versions of your library, you may recycle your QUnit unit tests as performance tests. Knowing that certain unit tests run faster or slower across different versions of your library can help you spot performance regressions, and you don't need to write a lot of performance tests anew.

To reuse your QUnit unit tests, link perfect-qunit.js after perfect.js in your HTML file.

You should first have some code like this:

<script type="text/javascript">
	QUnit.initPerfect({
		name: 'My performance test',
		a: 'lib/target_library_0.1.js',
		b: 'lib/target_library_0.2.js'
	});
</script>

then you should include your unit tests JavaScript file, and, finally, do this:

<script type="text/javascript">
	QUnit.runPerfect();
</script>

Examples

Please see the examples/ directory.

Third party libraries

Perfect uses:

Benchmarkjs: http://benchmarkjs.com/
lodash: http://lodash.com/
LazyLoad: https://github.com/rgrove/lazyload/
Mediator: https://github.com/ajacksified/Mediator.js
Bootstrap: https://github.com/twitter/bootstrap (only for the CSS)

They are deployed as part of perfect-libs.js.

Contributing

Clone the repository and fetch the submodules:

git clone git@github.com:siovene/perfectjs.git

Use Grunt to build:

grunt

Please remember to run grunt lint before submitting patches.

Testing

Perfect ships with unit tests. Please run npm install to install the required dependencies, install phantomjs using your distribution's package manager, and then do:

phantomjs tests/phantomjs-index.js tests/index.html

or simply:

npm test

Authors and contributors

Salvatore Iovene salvatore.iovene@intel.com