Cucumber step to set cookies in your Capybara session

To set a cookie in your test browser for cucumber tests, you need to know which driver you are using. Use the step below according to your driver.

Rack::Test

CopyGiven /^I have a "([^\"]+)" cookie set to "([^\"]+)"$/ do |key, value|
  headers = {}
  Rack::Utils.set_cookie_header!(headers, key, value)
  cookie_string = headers['Set-Cookie']

  Capybara.current_session.driver.browser.set_cookie(cookie_string)
end

Note that Rack::Utils is only used to find out the correct cookie header string (you don't want to generate it yourself) -- it is then passed to Capybara's browser. The browser will send the cookies when making the next request.

Cuprite Browser Show archive.org snapshot

CopyGiven /^I have a "([^\"]+)" cookie set to "([^\"]+)"$/ do |key, value|
   Capybara.current_session.driver.set_cookie(key, value)
end

Usage in feature tests

CopyGiven I have a "page_views" cookie set to "42"
When I visit the start page
Then something should happen

A word of advice

You should rarely care about doing the above. Usually, your integration tests should not be concerned with browser internals like cookies. However, if you want to test something like visitors with old cookies (which your application can't set any more) on the whole application stack, this is for you.