215 Browser automation with Capybara and Selenium WebDriver [2d]

We use Selenium WebDriver Show archive.org snapshot integrated with Cucumber/Capybara for full-stack integration testing.

Try and use it

Your forked MovieDB should already include a feature that uses a real browser. Add the @javascript tag to your other features to test it yourself.

When you run your cucumber feature now with NO_HEADLESS=1 geordi cucumber, you should see a browser opening. Get someone to help you if this does not work.

Some of your features might now fail. You might find solutions below:

Making peace with Selenium

Selenium is a powerful tool that you can use to test almost all user interfaces. However it has a lot of quirks you have to deal with. Luckily for you, someone else has already solved all major issues that the Capybara/Selenium combo brings with it.

Understand the following issues and solutions in depth:

• Difference between Capybara drivers
  • Rack::Test Show archive.org snapshot
  • selenium-webdriver Show archive.org snapshot
• Fixing flaky integration tests (also watch the video on YouTube Show archive.org snapshot )
• What does the @javascript tag do and how does it work?
• We used to use Selenium with Firefox, but now we run Selenium tests with Chrome instead, which doesn't have the same incompatibility issues as Firefox
  • Therefore we use Chrome in headless mode running Chrome in headless mode
• Use capybara lockstep to ensure requests don't bleed between steps Show archive.org snapshot
  • Read through the README of the capybara-lockstep Show archive.org snapshot gem. What problem does it solve and how does it work?
• Threads and processes in a Capybara/Selenium session
• Why do we need the database_cleaner gem for integration tests?
• Why your Cucumber feature loses cookies when run under Selenium
  
• Capybara cannot interact with the browser while a blocking dialog is open
  • How to configure Selenium WebDriver to not automatically close alerts or other browser dialogs
  • How to accept or deny JavaScript confirmation dialogs in Capybara/Selenium
  • Testing file downloads
• Taking screenshots in Capybara
• Capybara/Selenium: evaluate_script might freeze your browser, use execute_script
• How to: Start Selenium browser maximized or with custom window size
• Mock the browser time or time zone in Selenium features

Exercise: A walk through the forest

Work through the code of all Spreewald steps Show archive.org snapshot . Do you understand the implementation of each step?

Exercise: Recognize common culprits

Have a look at this code:

Copyclass User < ApplicationRecord
  def self.find_by_email(email)
    @cached_users ||= {}
    @cached_users[email] ||= User.find_by_email!(email)
  end
end

Could it cause your tests to become flaky?