[FIXED] Selenium::WebDriver::Error::JavascriptError: arguments[0] is undefined

Issue

After seeing that this is a problem with Firefox 35, I installed 34 and ran bundle exec rspec and my tests ran perfectly. But when I tried running it again, it somehow opened the newer version of Firefox as I get the following error again when I run my test suite:

 Selenium::WebDriver::Error::JavascriptError: arguments[0] is undefined

Is there a way to guarantee that I don't have Firefox 35 installed that Selenium is somehow finding and opening? I know that Firefox 34 is the version of the Firefox in my Applications directory, but I am not certain there isn't a replica copy of a newer firefox that Selenium is grabbing when launchy is used.

Solution

This is a known issue with the current release of selenium.

As @janders223 points out in a comment on another question, the temporary workaround for a Ruby project is to use the dev version of the selenium-webdriver gem.

Modify your Gemfile to specify the latest dev version (as of this writing):

gem 'selenium-webdriver', '>=2.45.0.dev3'

Then run bundle install.

Answered By - Mike Mazur