First you need to install wallaby.js package for Atom, if you haven’t done it yet.

For this tutorial I will use this sample calculator project. You can clone it to try locally:

git clone https://github.com/wallabyjs/calculator-sample.git

Once you have the source code locally, open the project folder in Atom.

There you will find a simple calculator project there with wallaby.js configuration file. Wallaby configuration file is a simple JavaScript file in your project root folder with just a couple of mandatory settings. The configuration file includes a list of files and tests of your application as well as some settings for various technologies that you may be using to build your project, such as Webpack or Browserify configuration Babel/CoffeeScript/TypeScript compiler options, etc.

Wallaby supports lots of technologies and scenarios, we have collection of sample projects with configuration files for different tools, frameworks and languages, such as Webpack, Browserify, ES6 and ES7 via Babel, TypeScript and CoffeeScript, React and Angular, node.js, etc.

First steps

Selecting wallaby.js config file

Wallaby.js for Atom needs to know what configuration file to use to run your tests. If you only have one file named wallaby.js/wallaby.conf.js in your project root, wallaby will automatically select it.

However, if you have multiple configuration files, use different naming convention or have the config file not in the root folder, you may select the config file from the Tree View with context menu or by opening the config in an editor tab and using Select as Wallaby.js Config context menu item.

Wallaby.js Command Palette

As you probably know, you may press Ctrl/Cmd + Shift + P in Atom to get the editor Command Palette in case if you’ve forgotten some shortcuts or just like invoking commands this way. There you may search for wallaby and use the found commands.

Also, for your convenience wallaby.js adds its own Command Palette to Atom that you may display by pressing Ctrl/Cmd + Shift + Space. It’s a fast and easy way to quickly use various wallaby features.

Wallaby.js Panel

One of the things you’ll be using a lot is wallaby.js Panel. It displays the name of the selected config file, failing test results as well as some test stats. You can open and collapse it by using the corresponding command (from the palette or via Ctrl/Cmd + Shift + T, T shortcut).

Let’s try starting wallaby.js: to do that you need to invoke wallaby Start command. You may do it by using the Ctrl/Cmd + Shift + T, R shortcut, or using wallaby Command Palette, or by clicking Start button on the wallaby.js Panel.

To stop wallaby.js, you may use Stop command or Stop button on the wallaby.js Panel.

Now let’s have some fun.

Wallaby.js in action

Once you have started wallaby.js, at the bottom right corner of the editor you’ll see wallaby status indicator. It’s job is pretty simple: when it displays a spinner - your tests are running, when it’s red - you have some failing tests, when it’s green - all of your tests are passing. You may also use the indicator to toggle wallaby.js Panel by clicking it.

Now, let’s open the sample calculator project spec (test/calculatorSpec.js).

When wallaby.js is running, you can see the code coverage in opened source files (specified in wallaby configuration file). As you can see, there are various colored squares displayed for each line of your source code.

Try jumping to any of the passing tests and break it, for example try changing the 2 plus 2 expectation result to 5 in the should add numbers test, or try breaking the code covered by the test. Right after the change wallaby.js automatically runs your tests and displays the result in Atom, right where you need to see it.

The code coverage and inline messages are automatically updated, just as you type.

Also, try editing some console.log arguments or just console.log any object you like.

This is a great way to quickly inspect any objects without having to leave your editor, without switching to any other console. Think how cool it is - your code editor is your console with all the required context.

We also recommend reading about some more powerful ways to log things and measure code performance with wallaby.js.

Watch expressions in action

Watch performance in action

Coverage indicators

Let’s have a look at the editor gutter where you may see some indicators. Here is what these coverage indicators mean:

Any indicator click triggers Show line tests command which we will review later.

Failing tests

Wallaby.js Panel displays all tests that are currently failing along with the error stacks and registered console.log calls. Some bits of the displayed information are hyperlinks that you can use with your mouse or keyboard (Enter) to navigate to different places, for example to the exact error line, or a failing test, or a place where something is logged to console. To quickly focus the panel you may use the Focus Panel wallaby command (Ctrl + 1), pressing Esc will return the focus back to the editor.

Commands

To help you writing/navigating your code and tests more efficiently, wallaby.js provides a few commands. You may see the full list in the wallaby.js Command Palette (Ctrl/Cmd + Shift + Space).

These commands include:

Troubleshooting

If you encounter any issues with configuring or using wallaby.js and not sure why it happens, check out our troubleshooting docs section or search our public repository issues to see if someone else have been experiencing something similar.

Another useful technique is to run wallaby.js with the debug flag set to true. In this case wallaby outputs a lot of additional information about the test execution progress which may help you to understand what’s going on if something goes wrong. The output can be viewed in the Developer Tools Console (Ctrl/Cmd + Alt + I).

Trial version

Note that trial version of wallaby.js (the one without a valid license) will be displaying prompts and stopping after some time, so you will need to restart the tool or your editor. Please contact us if you would like to arrange a trial period for yourself or your team without activation prompts and restarts.