Setting Up Chrome Selenium driver for Capybara when using chrome canary on a Mac

31 Dec 2014

We have been adding Rspec + Capybara to Suggestion.io to ensure we don’t create any regression bugs. There are plenty of resources online to set-up Capybara to use Selenium’s Chrome driver (instead of Firefox).

But, what if you are using Chrome Canary as your browser?

You would probably see the following error:

Selenium::WebDriver::Error::UnknownError: unknown error: cannot find Chrome binary

There are two ways to fix this issue:

### Solution 1 - Download Chrome

Whilst, searching for the solution, I ended up on ChromeDriver’s wiki. It clearly states that Chrome driver expects the Chrome binary to be in:

/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome

That’s exactly where Chrome is installed on a Mac, so, to fix this issue just download Chrome.

Solution 2 - Pass the location of Chrome Canary’s binary to Selenium Chrome Driver via Capybara

Downloading Chrome just for the sake of passing specs doesn’t make sense. Googling revealed that there’s something called ‘ChromeOptions’, but, how the hell do I pass that option from Capybara, so that it get’s passed correctly to Selenium Chrome driver. After, trawling through the capybara and selenium-webdriver source, I found a way to pass the location of Chrome Canary as the binary. Here’s how:

Capybara.register_driver :chrome do |app|
  Capybara::Selenium::Driver.new(app, 
    browser: :chrome, 
    desired_capabilities: {
      "chromeOptions" => {
        "binary" => '/Applications/Google Chrome Canary.app/Contents/MacOS/Google Chrome Canary' 
      } 
    })
end

The ‘binary’ option specifies the location of Chrome Canary’s binary on your Mac.

That was a couple of hours well spent. Hope it helps!