Setting up Rspec

4 min readFeb 6, 2018

In this post, I’d like to record for willing readers and my future-self how I go about configuring Rspec for writing tests in Rails. This will not be a tutorial on how to write tests, why to write tests or what kinds of tests to write, but rather a nuts and bolts reference for adding Rspec-driven testing tooling to a Rails project. There’s a lot of noise out there in the testing world, so I’ll try to make this post to-the-point.

Step 1 — Delete Any Existing Test Folders

If I’ve generated a new rails app using rails new <app> without using any additional flags, I remove the app/test directory:

Step 2 — Add Gems

I add the following gems to the :development, :test group in my Gemfile and run bundle.

group :development, :test do
  gem 'byebug', platform: :mri
  gem 'rspec-rails', '~> 3.5'
  gem 'factory_girl_rails'
  gem 'capybara'
  gem 'database_cleaner'
end

Briefly running through these gems one-by-one:

byebug allows for step-through debugging by placing byebug anywhere in the app.
rspec-rails is the testing framework.
factory_girl_rails replaces Rails fixtures for generating data to use in the tests.
capybara provides helper methods that make integration testing easier.
database_cleaner allows us to manage our testing database with precision: we decide when to wipe data (e.g. after, before tests).

Step 3 — Run Rspec Generator

Currently, the app directory doesn’t include a app/test/ directory (remember we deleted it in step 1), so I have nowhere to put my tests. This is where the Rspec generator, which will generate app/spec/, comes in:

rails generate rspec:install

This adds the following files in a app/spec directory:

spec/spec_helper.rb
spec/rails_helper.rb

and app/.rspec in the project’s root directory.

Now I’ve added the proper files to use Rspec instead of Minitest::Unit, but I still need to do a little more configuration before Rspec will work with the factory_girl_rails, capybara, and database_cleaner gems.

Step 4 — Configure Rspec

Open up spec/rails_helper.rb. All of the instructions from this section will be implemented in this file. I include the complete rails_helper.rb file at the bottom of this section.

database_cleaner

To use database_cleaner, I add require 'database_cleaner' below require 'rspec/rails', and change the following line in the Rspec.configure bloc from

config.use_transactional_fixtures = true

config.use_transactional_fixtures = false

Then I add the following to the Rspec.configure block:

RSpec.configure do |config|  #...omitted code...  config.use_transactional_fixtures = false  config.before(:suite) do
    DatabaseCleaner.clean_with(:truncation)
  end  config.before(:each) do
    DatabaseCleaner.strategy = :transaction
  end  config.before(:each, :js => true) do
    DatabaseCleaner.strategy = :truncation
  end  config.before(:each) do
    DatabaseCleaner.start
  end  config.after(:each) do
    DatabaseCleaner.clean
  end  config.before(:all) do
    DatabaseCleaner.start
  end  config.after(:all) do
    DatabaseCleaner.clean
  end #...omitted code...
 
end

capybara

To use capybara, I add require 'capybara/rspec' after require 'rspec/rails'.

factory_girl_rails

To use factory_girl_rails, I remove this line:

config.fixture_path = "#{::Rails.root}/spec/fixtures"

And add to the Rspec.configure block:

config.include FactoryGirl::Syntax::Methods

This will give me access to FactoryGirl methods like build and create. I place all of my factories in the spec/factories directory.

devise

If my app uses devise for authentication, I add:

config.include Devise::Test::ControllerHelpers, type: :controller

to the Rspec.configure block. This gives me helper methods like sign_in.

miscellaneous pointers

At the bottom of Rspec.configure block, you’ll see the following line:

config.infer_spec_type_from_file_location!

This allows rails to infer from the location of the spec file what kind of test it is and then give you context-specific helper methods (e.g. using get and post in controller tests if the file is found in the spec/controllers directory).

My complete rails_helper.rb file looks like this:

ENV['RAILS_ENV'] ||= 'test'require 'spec_helper'
require File.expand_path('../../config/environment', __FILE__)
require 'rspec/rails'
require 'database_cleaner'
require 'capybara/rspec'Dir[Rails.root.join('spec/support/**/*.rb')].each { |f| require f }
ActiveRecord::Migration.maintain_test_schema!RSpec.configure do |config|
  config.use_transactional_fixtures = false
  config.include FactoryGirl::Syntax::Methods
  config.include Devise::Test::ControllerHelpers, type: :controller
  config.before(:suite) do
    DatabaseCleaner.clean_with(:truncation)
  end
  config.before(:each) do
    DatabaseCleaner.strategy = :transaction
  end
  config.before(:each, js: true) do
    DatabaseCleaner.strategy = :truncation
  end
  config.before(:each) do
    DatabaseCleaner.start
  end
  config.after(:each) do
    DatabaseCleaner.clean
  end
  config.before(:all) do
    DatabaseCleaner.start
  end
  config.after(:all) do
    DatabaseCleaner.clean
  end
  config.infer_spec_type_from_file_location!
end

Step 5 — Write Tests

Now I’m ready to write some tests, all of which reside in the spec directory. Typically my spec directory looks something like this:

spec/
  controllers/
    user_controller_spec.rb
    resource_controller_spec.rb
  factories/
    user.rb
    resource.rb
  models/
    user_spec.rb
    resource_spec.rb
  mailers/
    mailer_spec.rb
  services/
    service_spec.rb  
  rails_helper.rb
  spec_helper.rb

This is by no means an exhaustive summary of all the different gems and tools that one can use in tests, but it does record my simple set up for getting going quickly. I hope it was useful.