RDee is a gem that makes it easy to switch between different browsers when you are using Selenium or Watir as your driver. You can also easily switch between running on a local browser or a browser that is part of a Selenium Grid on on Sauce Labs.


RDee was designed to make it easy for your tests to switch between different browsers. It can select browsers that are running on your local machine or on a Selenium Grid. The way you select a browser is by calling one of the following methods:

RDee.selenium_browser(target = :chrome, options = {})
# or
RDee.watir_browser(target = :chrome, options = {})

These methods take two optional parameters. The first is the target browser. The second is options that can be passed to that browser when it is started.

Specifying the target browser

As we saw in the previous section, you can specify the target browser by passing a symbol to the selenium_browser or watir_browser methods. The problem with this is that you would have to change the code if you wanted to use a different browser. RDee has made this simpler by allowing you to set the target browser using an environment variable. The environment variable is named RDEE_BROWSER. A couple of typical usage patterns are to set this in the cucumber.yml file for specific profiles or to simply set this on the command-line when running the tests. Here is an example of a cucumber.yml file:

default: RDEE_BROWSER=firefox --format pretty --color
chrome: RDEE_BROWSER=chrome --format pretty --color
safari: RDEE_BROWSER=safari --format pretty --color

From the command-line you could simply do this:

RDEE_BROWSER=chrome bundle exec cucumber

The format of the target passed to the methods or set in the environment variable determines what browser, version, and host os you get. The format follows the following pattern:


The first part of the target determines what browser to use. At the current time you can specify firefox, chrome, ie, safari, phantomjs or ios. In the near future we will be supporting more mobile platforms so stay tuned.

Immediately following the browser is the version. This is optional and if you do not specify it will select whatever version is available. It is up to you to make sure that the browser and version combination are valid.

For mobile the version is the version of the OS you require replacing the dot with an underscore. For example, :ios10_2 will use iOS 10.2 and :android4_4 will use Android 4.4. You will provide the additional information like the device type as additional values. See below.

Following the version there is an underscore followed by the host os. This value is also optional. Currently the following host os values are available:

host description
win10 Windows 10
win81 Windows 8.1
win8 Windows 8
win7 Windows 7
winxp Windows XP
mountain_lion OS X 10.8
mavricks OS X 10.9
yosemite OS X 10.10
el_capitan OS X 10.11
sierra macOS 10.12
linux Linux
ios 'iOS'
android 'Android'

The host os value is typically used when running the tests on a Selenium Grid. It is up to you to ensure that the host and requested browser combination exist on your grid.

Additional Configurations

Additional parameters can be set by calling the configure method on the RDee module. First of all, you can set the url value. If the url is set RDee will attempt to make a remote connect to the grid specified by the url. Additionaly you can specify whether it should use a persistent http connection as well as specify additional parameters that should be sent to a specific type of browser when it is used. Here are examples:

RDee.configure do | config |
  config.url = 'http://path.to.selenium.grid/wd/hub'
  config.persistent_http = true
  config.chrome_options = { :switches => %w[--disable-extensions] }
  config.firefox_options = { :switches => %w[--disable-popups] }
  config.ie_options = { :switches => %w[--disable-popups] }
  config.safari_options = { :switches => %w[--disable-popups] }
  config.ios_options = { :switches => %w[--disable-popups] }
  config.android_options = { :switches => %w[--disable-popups] }

Mobile Specific Additional Settings

Mobile is more complex that the standard desktop browsers. In order to get everything to work properly on a mobile platform you will need to provide some additional information. Here is an example:

mobile_capabilities = {
  appiumVersion: '1.6.4',
  deviceName: 'iPhone Simulator',
  deviceOrientation: 'portrait'
RDee.watir_browser(target = :ios10_2, desired_capabilities: mobile_capabilities)

For Android it is extremely simular:

mobile_capabilities = {
  appiumVersion: '1.6.4',
  deviceName: 'Google Nexus 7 HD Emulator',
  deviceOrientation: 'portrait'
RDee.watir_browser(target = :android4_4, desired_capabilities: mobile_capabilities)

Another way to specify these additional capabilities is to specify them in the configure block like this:

RDee.configure do | config |
  config.url = 'http://path.to.selenium.grid/wd/hub'
  config.ios_capabilities = {
    appiumVersion:      '1.6.4',
    deviceName:         'iPhone Simulator',
    deviceOrientation:  'portrait'
  config.android_capabilities = {
    appiumVersion:      '1.6.4',
    deviceName:         'Google Nexus 7 HD Emulator',
    deviceOrientation:  'portrait'

Using the config allows us to set the values via environment variables without changing code.

RDee.configure do | config |
  config.url = 'http://path.to.selenium.grid/wd/hub'
  config.ios_capabilities = {
    appiumVersion:      ENV['ios_appiumVersion'],
    deviceName:         ENV['ios_deviceName'],
    deviceOrientation:  ENV['ios_deviceOrientation']
  config.android_capabilities = {
    appiumVersion:      ENV['android_appiumVersion'],
    deviceName:         ENV['android_deviceName'],
    deviceOrientation:  ENV['android_deviceOrientation']

To see what options you should use please look at the Sauce Labs Configurator.


Add this line to your application's Gemfile:

gem 'RDee'

And then execute:

$ bundle

Or install it yourself as:

$ gem install RDee


  1. Fork it ( https://github.com/[my-github-username]/rd/fork )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request