Introduction: Configuration

Ensure tests are passing outside of Wallaby

Before you get started, we recommend ensuring that your tests are executing correctly (and passing) outside of Wallaby. While not strictly necessary, sometimes test environments (especially complex ones - e.g. babel + webpack + browser) are not working before starting Wallaby, which may confuse you into thinking that Wallaby is not working properly when instead the problem is with your tests or test runner configuration.

Automatic configuration

For many testing frameworks and environments Wallaby requires no configuration at all. Automatic configuration is available for projects that are using Jest >= v24, Angular CLI >= v8.2, Vitest, node:test, Vue CLI >= v4, Create-React-App >= v3, and NX Workspaces >= v8.

If automatic configuration for your testing framework is not yet supported, you may continue to use Wallaby with a simple configuration file.

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Overriding automatic defaults

In order to override any defaults, you may use a Wallaby Configuration file or add a wallaby section to your package.json file.

If you do not have a files or tests array defined in your configuration settings then Wallaby will use Automatic Configuration. If you have a files or tests array defined, then you must specify the autoDetect: true setting to use Automatic Configuration.

package.json

{
  "name": "...",
  ...

  "dependencies": {
    ...
  },

  "devDependencies": {
    ...
  },

  ...

  "wallaby": {
    ...
  }
}

wallaby.js

module.exports = () => ({
   autoDetect: true,
   ...
});

Configuration file

Wallaby.js configuration file lists your files/tests and describes the build/setup process for your testing environment.

For example, if you are using a compiler or a module bundler, it needs a configuration for the compiler, such as Babel or TypeScript compiler, or the module bundler, such as Browserify or Webpack.

These things are configured in wallaby.js configuration file, that should be placed to your project root folder. Recommended name is wallaby.js or wallaby.conf.js.

The configuration file is a simple JavaScript file, with a root object containing the properties listed below or exporting a function that returns an object of the same structure.

For example:

module.exports = function (wallaby) {
  return {
    files: [
      'src/**/*.js'
    ],

    tests: [
      'test/**/*Spec.js'
    ]
    ...
    // for node.js tests you need to set env property as well
    // https://wallabyjs.com/docs/integration/node.html
  };
};

By default wallaby.js uses Google Chrome (headless) to run tests. If you want to use wallaby.js to run your node.js tests, or run your tests in the latest Chromium/V8 via Electron, or run your tests in PhantomJs, you will also need to specify the env configuration property.

You may read more about various configuration settings, such as files, in the corresponding documentation sections. For example, how to configure wallaby to use Webpack or Babel.

Configuration in package.json

You may use wallaby section in your package.json file to configure Wallaby.js, specify some settings in addition to those specified in your Wallaby config file, or to or override automatic configuration mode defaults:

package.json

{
  "name": "...",
  ...

  "dependencies": {
    ...
  },

  "devDependencies": {
    ...
  },

  ...

  "wallaby": {
    "slowTestThreshold": 200
  }
}

Applying Configuration Changes

Wallaby determines your configuration once, when it first starts. This means that configuration changes will not take effect until Wallaby is next started.