Starting a webdriver server

If you aren't sure about what a webdriver server is, then download the Selenium standalone server.

It is a .jar file. Make sure you have Java and Firefox installed.

Assuming the file you downloaded is called selenium-server-standalone-2.45.0.jar, you can start the server with:

java -jar selenium-server-standalone-2.45.0.jar

If you are using macOS with Homebrew you can install the Selenium standalone server with:

brew install selenium-server-standalone

Follow the Homebrew post-install instructions to run the server locally.

Starting a PhantomJS webdriver server

If you are using macOS with Homebrew you can install PhantomJS with:

brew cask install phantomjs

Once you have installed phantomjs, run the following command.

phantomjs --wd

Now you can open a new console window and run your tests.

If you are using macOS with Homebrew you can install ChromeDriver with:

brew cask install chromedriver

Follow the Homebrew post-install instructions to run ChromeDriver locally.