WDIO Electron Service

WebdriverIO service for testing Electron applications

Enables cross-platform E2E testing of electron apps via the extensive WebdriverIO ecosystem. Adds electron-specific browser capabilities and handles chromedriver execution.

Spiritual successor to Spectron (RIP).

Installation

npm i -D wdio-electron-service

Or use your package manager of choice - yarn, pnpm, etc.

You will need to install WebdriverIO, instructions can be found here.

Chromedriver

wdio-electron-service needs chromedriver to work. The chromedriver version needs to be appropriate for the version of electron that your app was built with, so it is recommended to install it via electron-chromedriver as their versioning directly tracks electron releases. For example:

npm i -D electron-chromedriver@18

The above command installs electron-chromedriver v18 which installs the chromedriver version that will work with an app built using electron 18.

Alternatively you can install chromedriver directly or via some other means, in this case you will need to specify the chromedriverCustomPath property.

npm i -D chromedriver@100  # for Electron 18 apps
npm i -D chromedriver@96  # for Electron 16 apps

        chromedriver: {
          port: 9519,
          logFileName: 'wdio-chromedriver.log',
          chromedriverCustomPath: require.resolve('chromedriver/bin/chromedriver') // resolves to chromedriver binary
        },

Example Configuration

To use the service you need to add electron to your services array, followed by a configuration object:

// wdio.conf.js
const { join } = require('path');
const fs = require('fs');

const packageJson = JSON.parse(fs.readFileSync('./package.json'));
const {
  build: { productName },
} = packageJson;

const config = {
  outputDir: 'all-logs',
  // ...
  services: [
    [
      'electron',
      {
        appPath: join(__dirname, 'dist'),
        appName: productName,
        appArgs: ['foo', 'bar=baz'],
        chromedriver: {
          port: 9519,
          logFileName: 'wdio-chromedriver.log',
        },
      },
    ],
  ],
  // ...
};

module.exports = { config };

API Configuration

If you wish to use the electron APIs then you will need to import the preload and main scripts. At the top of your preload:

import 'wdio-electron-service/preload';

And at the top of your main index file (app entry point):

import 'wdio-electron-service/main';

The APIs should now be available in tests. Currently available APIs: app, mainProcess, browserWindow.

const appName = await browser.electronApp('getName');

Custom Electron API

You can also implement a custom API if you wish. To do this you will need to define a handler in your main process:

import { ipcMain } from 'electron';

ipcMain.handle('wdio-electron', () => {
  // access some Electron or Node things on the main process
  return 'such api';
});

The custom API can then be called in a spec file:

const someValue = await browser.electronAPI('wow'); // default
const someValue = await browser.myCustomAPI('wow'); // configured using `customApiBrowserCommand`

Example

See wdio-electron-service-example for an example of "real-world" usage in testing a minimal electron app.

Configuration

appPath: string

The path to the built app for testing. In a typical electron project this will be where electron-builder is configured to output, e.g. dist by default. Required to be used with appName as both are needed in order to generate a path to the electron binary.

appName: string

The name of the built app for testing. Required to be used with appPath as both are needed in order to generate a path to the Electron binary.

It needs to match the name of the install directory used by electron-builder; this value is derived from your electron-builder configuration and will be either the name property (from package.json) or the productName property (from electron-builder config). You can find more information regarding this in the electron-builder documentation.

binaryPath: string

The path to the electron binary of the app for testing. The path generated by using appPath and appName is tied to electron-builder output, if you are implementing something custom then you can use this.

appArgs: string[]

An array of string arguments to be passed through to the app on execution of the test run.

customApiBrowserCommand: string

default electronAPI

The browser command used to access the custom electron API.

Chromedriver configuration

This service wraps the wdio-chromedriver-service, you can configure the following options which will be passed through to that service:

chromedriver.port: number

default 9515

The port on which chromedriver should run.

chromedriver.path: string

default /

The path on which chromedriver should run.

chromedriver.protocol: string

default http

The protocol chromedriver should use.

chromedriver.hostname: string

default localhost

The hostname chromedriver should use.

chromedriver.outputDir: string

default defined by config.outputDir

The path where the output log of the chromedriver server should be stored. If not specified, the WDIO outputDir config property is used and chromedriver logs are written to the same directory as the WDIO logs.

chromedriver.logFileName: string

default wdio-chromedriver.log

The name of the output log file to be written in the outputDir.

chromedriver.chromedriverCustomPath: string

default require.resolve('electron-chromedriver')

The path of the chromedriver binary to be executed. If not specified, the service will look for the electron-chromedriver module.