Selenium Standalone Service

Handling the Selenium server is out of the scope of the actual WebdriverIO project. This service helps you to run Selenium seamlessly when running tests with the WDIO testrunner. It uses the well-known selenium-standalone NPM package that automatically sets up the standalone server and all required drivers for you.

Note: If you use this service you don't need any other driver services (e.g. wdio-chromedriver-service) anymore. All local browsers can be started using this service.

Installation

Before starting make sure you have JDK installed.

The easiest way is to keep @wdio/selenium-standalone-service as a devDependency in your package.json. You can do it by:

npm install @wdio/selenium-standalone-service --save-dev

Instructions on how to install WebdriverIO can be found here.

Configuration

By default, ChromeDriver, Geckodriver and some other browser drivers based on the OS are available when installed on the user's system. To use the service you need to add selenium-standalone to your service array:

/**
 * simplified mode (available since v6.11.0)
 * set `true` to use the version provided by `selenium-standalone`, 'latest' by default
*/
export const config = {
    // ...
    services: [
        ['selenium-standalone', { drivers: { firefox: '0.33.0', chrome: true, chromiumedge: 'latest' } }]
    ],
    // ...
};

Control browser driver installation/running separately.

// wdio.conf.js
const drivers = {
    chrome: { version: '112.0.5615.49.101' }, // https://chromedriver.chromium.org/
    firefox: { version: '0.33.0' }, // https://github.com/mozilla/geckodriver/releases
    chromiumedge: { version: '114.0.1791.0' } // https://developer.microsoft.com/en-us/microsoft-edge/tools/webdriver/
}

export const config = {
    // ...
    services: [
        ['selenium-standalone', {
            logPath: 'logs',
            installArgs: { drivers }, // drivers to install
            args: { drivers } // drivers to use
        }]
    ],
    // ...
};

Custom Configurations

By default the service starts on localhost:4444 and ensures that all capabilities are able to connect to it. If you prefer to run on a different port please specify port as an option in your capabilities, e.g.:

// wdio.conf.js
export const config = {
    // ...
    services: [
        ['selenium-standalone', {
            logPath: './temp',
            args: {
                version: "4.4.0",
                seleniumArgs: ['--host', '127.0.0.1','--port', '5555']
            },
        }]
    ],
    capabilities: [{
        browserName: 'chrome',
        port: 5555
    }, {
        browserName: 'firefox',
        port: 5555
    }, {
        browserName: 'MicrosoftEdge',
        port: 5555
    }]
    // ...
}

Options

The following options can be added to the wdio.conf.js file.

logPath

Path where all logs from the Selenium server should be stored.

Type: String

Default: {}

Example:

logPath : './',

args

Map of arguments for the Selenium server, passed directly to Selenium.start(). Please note that latest drivers have to be installed, see installArgs.

Type: Object

Default: {}

Example:

args: {
    version : "4.4.0",
    drivers : {
        chrome : {
            version : "112.0.5615.49.101",
            arch    : process.arch
        }
    }
},

installArgs

Map of arguments for the Selenium server, passed directly to Selenium.install().

By default, versions will be installed based on what is set in the selenium-standalone package. The defaults can be overridden by specifying the versions.

Type: Object

Default: {}

Example:

installArgs: {
    version : "4.4.0",
    baseURL : "https://github.com/SeleniumHQ/selenium/releases/download",
    drivers : {
        chrome : {
            version : "112.0.5615.49.101",
            arch    : process.arch,
            baseURL : "https://chromedriver.storage.googleapis.com"
        }
    }
},

skipSeleniumInstall

Boolean for skipping selenium-standalone server install.

Type: Boolean

Default: false

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For more information on WebdriverIO see the homepage.