nightwatch.conf.js

The Nightwatch test runner binary expects a configuration file, using by default either a nightwatch.conf.js or nightwatch.json file from the current working directory. nightwatch.conf.js is taking precedence if both files are found.

From Nightwatch 2, you can also specify the config file to return a Promise and the test runner will wait for it to resolve.

Here's an example config file which uses Firefox as target browser and assumes that the geckodriver NPM package is installed.

module.exports = {
  // An array of folders (excluding subfolders) where your tests are located;
  // if this is not specified, the test source must be passed as the second argument to the test runner.
  src_folders: [],

  webdriver: {
    start_process: true,
    port: 4444,
    server_path: require('geckodriver').path,
    cli_args: [
      // very verbose geckodriver logs
      // '-vv'
    ]
  },

  test_settings: {
    default: {
      launch_url: 'https://nightwatchjs.org',
      desiredCapabilities : {
        browserName : 'firefox'
      }
    }
  }
};

Auto-generated Configuration

Since version 1.3, Nightwatch will generate a nightwatch.conf.js config file on the first run or if no other config file has been found, based on the operation system and existing driver packages. If a nightwatch.json or nightwatch.conf.js file is found in the current folder, nothing happens and the file is not generated.

Feel free to edit this file and adapt the settings however you see fit. So far, we have included support for Chrome, Firefox, Safari, and Internet Explorer.

The following packages can be used from NPM and, if installed, Nightwatch will automatically detect and configure the test runner:

Working with Test Environments

It is likely you will run your tests against multiple environments and/or different browsers. Nightwatch provides a concept for defining different environments, in which you can set specific test settings.

The environments are located under the "test_settings" dictionary in the configuration file. A default environment is always required from which the other environments inherit the settings. You can overwrite any test setting for each environment as needed.

The auto-generated nightwatch.conf.js contains several pre-defined test environments for running tests against several different browsers (Firefox, Chrome, Safari), and also for running tests using Selenium Server or popular cloud testing provider Browserstack.

Here’s an extract:

module.exports = {
  src_folders: [],

  test_settings: {
    default: {
      launch_url: 'https://nightwatchjs.org'
    },

    safari: {
      desiredCapabilities : {
        browserName : 'safari',
        alwaysMatch: {
          acceptInsecureCerts: false
        }
      },
      webdriver: {
        port: 4445,
        start_process: true,
        server_path: '/usr/bin/safaridriver'
      }
    },

    firefox: {
      desiredCapabilities : {
        browserName : 'firefox'
      },

      webdriver: {
        start_process: true,
        port: 4444,
        server_path: require('geckodriver').path
      }
    }
  }
}

Considering this setup, to run tests, for instance, against Safari, we would run the following the command-line:

nightwatch --env safari

Refer to the Defining Test Environments page to learn more about how to use test environments.

Working with Test Globals

Another useful concept that Nightwatch provides is test globals. In its most simple form, it is a dictionary of name-value pairs which is defined in your configuration file.

Globals can be defined either as a "globals" property or as an external file which is specified as the "globals_path" property.

Here's an example definition using the "globals" property in nightwatch.json:

{
  "src_folders": [],

  "test_settings": {
    "default": {
      "launch_url": "https://nightwatchjs.org",

      "globals": {
        "myGlobalVar" : "some value",
        "otherGlobal" : "some other value"
      }
    }
}
}

Like the launch_url property, the globals object is made available directly on the Nightwatch api which is passed to the tests.

module.exports = {
  'Demo test' : function (browser) {

    console.log(browser.globals.myGlobalVar); // myGlobalVar == "some value"
}
};

Refer to the Using Test Globals page to learn more about how to use test globals.

Using Env variables

Any config value in either nightwatch.conf.js or nightwatch.json can be specified as the name of an environment variables. Nightwatch will automatically populate the value, if found, from process.env.

Dotenv files are also supported and will be used if an .env file is found in the current working directory.

Here's an example from the generated nightwatch.conf.js:

module.exports = {
  src_folders: [],

  test_settings: {
    default: {
      launch_url: 'https://nightwatchjs.org'
    },

    browserstack: {
      webdriver: {
        start_process: false
      },

      selenium: {
        host: 'hub-cloud.browserstack.com',
        port: 443
      },

      desiredCapabilities: {
         browserName: 'chrome',
        'bstack:options' : {
          userName: '${BROWSERSTACK_USER}',
          accessKey: '${BROWSERSTACK_KEY}',
        }
      }
    }
  }
}

Manual Configuration

At this point you should have at least one WebDriver package installed in your project. Refer to the WebDriver installation section for details. Create the nightwatch.json in the project's root folder.

Assuming you have downloaded or installed the ChromeDriver service, the simplest nightwatch.json file will look like this, where node_modules/.bin/chromedriver is the path where ChromeDriver is installed:

{
  "src_folders" : ["tests"],

  "webdriver" : {
    "start_process": true,
    "server_path": "node_modules/.bin/chromedriver",
    "port": 9515
  },

  "test_settings" : {
    "default" : {
      "desiredCapabilities": {
        "browserName": "chrome"
      }
    }
  }
}

Further Reading

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