firefoxOptions

Starting with geckodriver 0.26.0 additional capabilities exist if Firefox or an application embedding GeckoView has to be controlled on Android:

androidPackage (string, required)

The package name of Firefox, e.g. org.mozilla.firefox, org.mozilla.firefox_beta, or org.mozilla.fennec depending on the release channel, or the package name of the application embedding GeckoView, e.g. org.mozilla.geckoview_example.

androidActivity (string, optional)

The fully qualified class name of the activity to be launched, e.g. .GeckoViewActivity. If not specified, the package's default activity will be used.

androidDeviceSerial (string, optional)

The serial number of the device on which to launch the application. If not specified and multiple devices are attached, an error will be returned.

androidIntentArguments (array of strings, optional)

Arguments to launch the intent with. Under the hood, geckodriver uses Android am to start the Android application under test. The given intent arguments are appended to the am start command. See Android's specification for intent arguments for details. This allows to control how the application is launched and to include optional extras for enabling and disabling features. For example, to launch with the view action and a specified URL before navigating as part of a test, include:

{
  "androidIntentArguments": [
    "-a",
    "android.intent.action.VIEW",
    "-d",
    "https://example.com"
  ]
}

For example, to specify a boolean extra that can be processed with android.content.Intent.getBooleanExtra, include:

{
  "androidIntentArguments": ["--ez", "customBooleanFlagName", "true"]
}

env (Env object)

Map of environment variable name to environment variable value, both of which must be strings, that will be forwarded to application process running on the Android device.

A JSON Object that may have any of these fields:

level (string)

Set the level of verbosity of geckodriver and Firefox. Available levels are trace, debug, config, info, warn, error, and fatal. If left undefined the default is info. The value is treated case-insensitively.

A JSON Object with one entry per preference to set. The preference will be written to the profile before starting Firefox. A full list of available preferences is available from visiting "about:config" in your Firefox browser. Some of these are documented in this source file.

An example of a preference object:

{
  "dom.ipc.processCount": 8,
  "javascript.options.showInConsole": false
}

A JSON Object with one entry per environment variable to set. On Desktop, the Firefox under test will launch with given variable in its environment. On Android, the GeckoView-based App will have the given variable added to the env block in its configuration YAML.

An example of an env object:

{
  "MOZ_LOG": "nsHttp:5",
  "MOZ_LOG_FILE": "/mnt/sdcard/log"
}

The following is an example of a full capabilities object that selects a specific Firefox binary to run with a prepared profile from the filesystem in headless mode. It also increases the number of IPC processes through a preference, turns off chrome errors/warnings in the console, and enables more verbose logging:

{
  "capabilities": {
    "alwaysMatch": {
      "moz:firefoxOptions": {
        "binary": "/usr/local/firefox/bin/firefox",
        "args": ["-headless", "-profile", "/path/to/my/profile"],
        "prefs": {
          "dom.ipc.processCount": 8,
          "javascript.options.showInConsole": false
        },
        "log": { "level": "trace" },
        "env": {
          "MOZ_LOG": "nsHttp:5",
          "MOZ_LOG_FILE": "/path/to/my/profile/log"
        }
      }
    }
  }
}

The moz:firefoxOptions must be placed—as above—inside alwaysMatch, or in one of the firstMatch capabilities objects as seen here:

{
  "capabilities": {
    "firstMatch": [
      {"moz:firefoxOptions": …}
    ]
  }
}

This runs the GeckoView example application as installed on the first Android emulator running on the host machine:

{
  "capabilities": {
    "alwaysMatch": {
      "moz:firefoxOptions": {
        "androidPackage": "org.mozilla.geckoview_example",
        "androidActivity": "org.mozilla.geckoview_example.GeckoView",
        "androidDeviceSerial": "emulator-5554",
        "androidIntentArguments": ["-d", "http://example.org"],
        "env": {
          "MOZ_LOG": "nsHttp:5",
          "MOZ_LOG_FILE": "/mnt/sdcard/log"
        }
      }
    }
  }
}

• geckodriver's documentation on supported Firefox capabilities
• Chrome-specific WebDriver capabilities (goog:chromeOptions)
• List of WebDriver capabilities
• New Session command