karma-electron

karma-electron

Karma launcher and preprocessor for Electron

This was written to allow for directly testing in Electron where we might want require to work automatically

Features:

• Tested via CI on Linux and Windows
• Support for Node.js integration in the renderer process (e.g. node_modules, __filename, relative paths for require)
• Support for hidden browser windows
• Support for isolated test runs to prevent cookie/localStorage pollution

Requirements:

• karma>=1.1.0 to work within electron's security policy for shared context between parent/child windows
  • See https://github.com/karma-runner/karma/pull/1984 for more information

Notices:

• This plugin has been tested against electron@0.37.4 and electron@1.3.3 but should support the latest version
• This plugin is best suited for testing the renderer portion of an electron application
  • For testing a full application, see electron's documentation on Selenium and WebDriver
  • https://github.com/electron/electron/blob/v1.3.6/docs/tutorial/using-selenium-and-webdriver.md

Breaking changes in 5.0.0

We have corrected inaccuracies with file:// behavior from Electron. For example:

• __filename is now Karma's context.html
• Relative paths for require resolve from Karma's context.html directory

We have transferred support for this to the option client.loadScriptsViaRequire which loads scripts via require and has the original expected Node.js behavior

For more information, see https://github.com/twolfson/karma-electron/issues/11

Getting Started

On a project that has been set up with karma init already, install the module via:

# Install our module and `electron-prebuilt`
npm install karma-electron electron-prebuilt

Then, configure the module:

// Inside `karma.conf.js`
browsers: ['Electron']

// If you would like Node.js integration support (e.g. `require`)
//   then, you must include this in `preprocessors` and `client`
// DEV: preprocessors is for backfilling `__filename` and local `require` paths
preprocessors: {
  '**/*.js': ['electron']
},
// DEV: `useIframe: false` is for launching a new window instead of using an iframe
//   In Electron, iframes don't get `nodeIntegration` priveleges yet windows do
client: {
  useIframe: false
}

Then, we can run Karma:

karma start

Documentation

Environment variables

• ELECTRON_BIN - Override path to use for electron
  • By default, we will use path given by electron-prebuilt

Example:

ELECTRON_BIN=/usr/bin/electron karma start

Script configuration

We support the following configurations:

• client Object - Container for configuring child windows loaded from Karma
  • loadScriptsViaRequire Boolean - Load scripts via require instead of <script src=
    • This sets __filename, __dirname, and module to match the script instead of Karma's context.html
    • By default, this is false and we directly load the original scripts content

Example:

module.exports = function (config) {
  config.set({
    // Use `require` instead of `<script src=` to load scripts
    client: {
      loadScriptsViaRequire: true
    }
  });
};

Launcher configuration

We support configuration via Karma's custom launcher inheritance:

• flags Array - List of Chromium flags to alter Electron's behavior
  • https://github.com/atom/electron/blob/v0.36.9/docs/api/chrome-command-line-switches.md
  • We added support for a --show to allow making the Karma window visible
• userDataDir String - Directory to store cookies/localStorage information
  • By default, this is a random directory generated by Karma (e.g. /tmp/karma-5355024)

Example:

module.exports = function (config) {
  config.set({
    // Specify usage of our custom launcher
    browsers: ['CustomElectron'],

    // Define a custom launcher which inherits from `Electron`
    customLaunchers: {
      CustomElectron: {
        base: 'Electron',
        userDataDir: __dirname + '/.electron',
        flags: ['--show']
      }
    }
  });
};

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint via npm run lint and test via npm test.

Donating

Support this project and others by twolfson via gratipay.

Unlicense

As of Mar 03 2016, Todd Wolfson has released this repository and its contents to the public domain.

It has been released under the UNLICENSE.