Question

I’m reading the new version of “Rails Tutorial” by Michael Hartl and, since I’m pretty fond in BDD with Cucumber, I found myself concerned about what the author points out here: http://ruby.railstutorial.org/chapters/sign-in-sign-out?version=3.2#sec:rspec_custom_matchers

In few words the main hassle with Cucumber is that it’s impossible to DRY implementation-dependent tests like this:

Then /^he should see an error message$/ do
  page.should have_selector('div.alert.alert-error', text: 'Invalid')
end

writing RSpec custom matchers like this:

RSpec::Matchers.define :have_error_message do |message|
  match do |page|
    page.should have_selector('div.alert.alert-error', text: message)
  end
end 

Because such a custom matcher must be put in spec/support/utilities.rb and can be called from RSpec integration tests but not from Cucumber step definitions.

Are you positive / what you think about it?

Thank you.

Answer 1

You can put implementation-dependent or reusable methods, locators to Cucumber World.

Example for your scenario:

# step_definitions/general_steps.rb
Then /^he should see an error message "(.+)"$/ do |text|
  within(error_message) do
    page.should have_content(text)
  end
end

# support/general_helpers.rb
module GeneralHelpers
  def error_message
    page.first('div.alert.alert-error')
  end
end

World(GeneralHelpers)

Here are some articles that refer to this approach:

• It’s time to clean up your mess: refactoring Cucumber step definitions
• Using Cucumber World