Wallaby.js runs your JavaScript tests immediately as you type and displays execution results in your code editor. It also provides beautiful test and code coverage reports updated in realtime.


What is wallaby.js?

Wallaby.js is an integrated test runner that enables highly productive JavaScript (or TypeScript, or CoffeeScript) unit testing workflow. It runs your unit tests immediately as you type and displays various execution results, including code coverage and inline messages, right inside your code editor. The tool is insanely fast, because it only executes tests affected by your code changes and runs your tests in parallel.

Wallaby.js is great for doing JavaScript (or TypeScript, or CoffeeScript) TDD (Test-driven development) or BDD (Behavior Driven Development), while also working nicely for other approaches.

There is no vendor, API or framework lock-in when using wallaby.js, because the tool is just using your testing framework and assertion libraries. You are getting a productivity boost with wallaby.js, and you will always be able to run your tests without the tool.

Once you have wallaby.js installed and running in any of the supported editors, you may also use wallaby.js browser app to get the realtime test execution and code coverage reports connected to your editor.

Who is using wallaby.js?

Thousands of individual professional developers and companies (including many of Fortune 500 companies and well-known tech giants) all over the world have already become more productive with wallaby.js. Even software development tools vendors, such as our friends from JetBrains, are trusting wallaby.js to help building other development tools.

What are our users saying?

Show more happy users

How much does wallaby.js license cost?

There are no free tools, unless your time has no value. You may find our pricing and licensing details on the pricing page.

Do I need to use some new APIs in my tests or change my tests/code to run them with wallaby.js?

No. Wallaby.js just makes your code editor smarter and your tests to run faster. No need to switch and invest into new frameworks, commands, or APIs - just use your existing testing libraries.

There's no vendor, API or framework lock-in when using wallaby.js. You are getting a productivity boost with wallaby.js, but you will always be able to run your tests without the tool.

What about a list of main features?

  • Supports continuous testing in your code editor:
    • WebStorm, IntelliJ IDEA, PhpStorm, Rider, RubyMine, PyCharm
    • Visual Studio Code
    • Atom Text Editor
    • Visual Studio 2017,
      Visual Studio 2019
    • Sublime Text
  • Supports browser code unit testing (via Chrome, PhantomJs, Electron or node.js) and node.js unit testing.
  • Shows live test coverage.
  • Allows to quickly inspect object values.
  • Provides beautiful realtime test and coverage reports.
  • Shows failed expectations, errors and console.log messages inline, where and when they occur.
  • Shows compact and side-by-side diff views for failing equality assertions and snapshots.
  • Supports many testing frameworks (Jasmine, QUnit, Mocha, Jest + snapshots, and AVA).
  • Supports ES.next, JSX, Babel.
  • Supports TypeScript, CoffeeScript, Flow.
  • Supports Webpack and Browserify.
  • Extensible via preprocessors, compilers and more.
  • Runs tests affected by code changes.
  • Runs tests in parallel.
  • Runs selected test(s), can update individual test(s) snapshots.

Where can I find more information about wallaby.js, such as tutorials and samples?

You can find more information, detailed tutorials and sample project links in our documentation.

How is it different from Karma, Mocha runner, Jest CLI runner, etc.?

With other test runners you either need to run your tests manually, or, at best, configure them to run the tests when you save your source code files. Those runners either execute all of your tests or, at best, all tests in all spec files affected by all uncommitted code changes, even if you are primarily editing just one file. So, as your project grows, it takes more and more time to complete the task. The test execution results are displayed somewhere outside of your code editor, and constant context switching to view the results is a productivity killer.

Wallaby.js runs your unit tests immediately as you type, no need to run anything manually, there's even no need to save files. The tool calculates and runs the minimum required number of tests affected by your code changes, often it is just a single test - and no other testing tool is capable of operating on this level. So no matter how large your project grows - the feedback is almost instant with wallaby.js. Test execution results, including code coverage, are displayed and updated in real time right where you need it — in your code editor, next to the line of code that you're editing.

Can I use wallaby.js with Jasmine, Mocha, QUnit, AVA, or Jest?

Yes. You can use your favorite testing framework, any mocking framework (such as Sinon.js), any assertion library (such as Chai.js, Expect.js, Should.js, Jasmine built-in one, etc.) with wallaby.js. No matter how awesome and fast your testing framework is (like Jest, Mocha, Jasmine, AVA, etc.), wallaby.js makes it even more awesome and faster with the features it adds.

Does wallaby.js support Angular, React, Backbone.js, Aurelia, etc.?

Yes. As long as you can write tests for your application, wallaby.js can run them. Check out our tutorials for testing Angular and React applications.

What about node.js?

Wallaby.js supports node.js testing. In fact, wallaby.js is written in node.js and we write tests for wallaby.js using wallaby.js.

What about ES.next or JSX?

ES.next is supported both natively for engines that can execute it and via code transpilers, such as Babel. You can see realtime coverage for your generators, classes, arrow functions and much more with wallaby.js. For JSX, not only does wallaby.js understand its syntax, but it also displays coverage inside JavaScript expressions within JSX elements.

What about TypeScript, CoffeeScript, Flow?

Wallaby.js has zero-configuration support for TypeScript and CoffeeScript. Babel is also fully supported.

What about Browserify or Webpack?

Wallaby.js supports both Browserify and Webpack via open source plugins. These plugins not only use incremental compilation, but also leverage browser caching to provide the best performance.

What about code preprocessors like in Karma?

Wallaby.js supports Karma-like preprocessors. Simply provide a function invoking an existing node module.

Do I have to install any standalone applications with wallaby.js?

No. All you need to install is the wallaby.js plugin for your code editor, period. No new command line tools or browser plugins. Our goal is not to add more things between you and the feedback from your tests. In fact, it's the opposite: wallaby.js eliminates any unnecessary context switching, so it's just you and your test feedback, right where and when you write your code.

Do I have to use TDD with wallaby.js or do I have to write my code first?

Wallaby.js is agnostic of any software development techniques. It helps you be more productive whether you're doing JavaScript TDD, writing tests after, or using any mixed approach.

Who stands behind wallaby.js?

At the core of our team are professional JavaScript developers and professional development tools makers. Not only do we know and love the language and the ecosystem, but we have also dedicated our careers to making programmers happier and more productive.

Where is your changelog, and what does the roadmap for wallaby.js look like?

Our changelog is in our public repository.

Wallaby.js roadmap:

How can I contact you?

Please feel free to send us an email to [email protected] or a message on twitter @WallabyJs and we will get back to you shortly.

How can I subscribe to wallaby.js news?

Follow us on twitter @WallabyJs to receive all the latest news.

We also send out project updates every now and then. Have a look at our past newsletters to decide if they’re worth subscribing to.