Today I Learned

A Hashrocket project

Open devtools when running a Selenium Chrome test

The Network tab in Chrome devtools doesn’t record requests unless devtools is open. This makes debugging specific issues in tests much harder. It’s great being able to see which api requests were made and what payloads they returned.

You can start Chrome with devtools open though with the the chrome option --auto-open-devtools-for-tabs.

If you are using Selenium with Chrome in a Ruby integration test, you can pass the option

opts = {
  browser: :chrome,
  options: Selenium::WebDriver::Chrome::Options.new(
  args: %w(--auto-open-devtools-for-tabs --window-size=2400,2400)
)
}

Capybara.register_driver :chrome do |app|
  Capybara::Selenium::Driver.new(app, opts)
end

Opening devtools automatically may restrict your window size enough to disrupt some of your tests in which case you can set -window-size to a value that accomodates your website.