Feature testing is high level testing that allows us to go through our entire system, ensuring that each and every component is working perfectly fine. The test-cases written for it are termed as feature specs, which requires capybara.
In this blog, we will be focussing on writing feature specs using capybara with rspec. More specifically, we are going to look at capybara key features as well as, how capybara specs looks like.
We as a developer are mainly focussed about the underlying things, but we should also consider end user’s view. So, Capybara comes to rescue, it lets you write yours test-cases from user’s perceptive i.e, how end users would interact with your system. It is a ruby gem build on the top of underlying web-based driver and these drivers drive our browsers based on what our master ‘capybara’ says.
There are multiple web-drivers supported by capybara, some of these are as follows:
It is one of the most popular driver and by default it supports Firefox browser where we can actually visualize our tests. It uses browser’s Javascipt Engine making it feel like having a actual human Q/A department interacting with our system. Also, we can configure it to be used in headless-mode which is specifically good from time and CI perspective.
This one runs our test-cases in PhantomJS browser with full JavaScipt support. It decreases the overall testing time by reducing the number of dependencies needed by CI server. But to use this, our system must have PhantomJS installed. Also, TravisCI, CircleCI have PhantomJS preinstalled. For more information you can refer poltergeist and phantomjs.
Provided you have installed Ruby, Rails and Rspec, we have to install Capybara. Here we will be using poltergeist driver which depends on PhantomJS, so firstly we need to have PhantomJS.
brew install phantomjs
sudo port install phantomjs
Installing Capybara and Poltergeist
Add this to Gemfile and run bundle install.
#Gemfile ... gem 'capybara' gem 'poltergeist'
After installing it, we need to tell our RSpec that we want to use Capybara with Poltergeist by adding this to spec/rails_helper.rb:
If we want to use web-driver other than poltergeist, we can include that here in place of poltergeist in the above mentioned file. But if we do not specify any capybara driver, than by default it will use rack::test.
As we have already installed everything, lets move onto how to write feature specs using capybara?
Consider a scenario, where our app has a home page and on that page we have a Log in button, so when a already registered user clicks on that Log in button she/he should be taken to a dashboard page.
Let’s test this feature using capybara:
require 'rails_helper' RSpec.feature "Log In" do background do @user = create :user, email: 'email@example.com' end scenario "signing in with valid credentials", js: true do visit '/homes' expect(page).to have_link('Log in') within(".login") do click_link 'Log in' end within(".sign-up") do fill_in 'Email', with: @user.email fill_in 'Password', with: 'testpassword' click_button 'Log In' end expect(page).to have_text('Dashboard page') end end
In order to use DatabaseCleaner, we have to include this in our Gemfile and run bundle install:
#Gemfile .... group :test do gem 'database_cleaner' end
After that, we have to configure our DatabaseCleaner strategy in spec/rails_helper.rb:
#spec/rails_helper.rb RSpec.configure do |config| config.use_transactional_fixtures = false config.before(:suite) do DatabaseCleaner.clean_with(:truncation) end config.around(:each) do |example| DatabaseCleaner.strategy = :truncation # Start transaction DatabaseCleaner.cleaning do # Run example example.run end end end
There are many ways as well as frameworks for doing end-to-end testing, one is using capybara with rspec which we have already covered in this blog. We can also do this testing using minitest that I’ll be covering in my next blog. Stay tuned 🙂