Preparing RSpec for Rails

Since testing is important, I read a book about RSpec and summarized it here. I’m writing down the setup process as a memo so I won’t forget.

Everyday Rails - Introduction to Rails Testing with RSpec

Setting up RSpec.

Environment

Rails 5.1.1
Ruby 2.5.1
RSpec 3.6

Setup

In the past, you had to install various things, but starting with RSpec 3.6, the process has become much simpler.

Install rspec-rails and spring-commands-rspec to speed up the test suite startup time.

Gemfile

group :development, :test do
 gem 'rspec-rails', '~> 3.6.0'
 gem "factory_bot_rails"
end

group :development do
  gem 'spring-commands-rspec'
end

After adding the above to the Gemfile:

$ bundle install

Create a binstub:

$ bundle exec spring binstub rspec

Test Database

If there is no test database, add it as follows.

SQLite

config/database.yml
test:
  <<: *default
  database: db/test.sqlite3

MySQL or PostgreSQL

config/database.yml
test:
  <<: *default
  database: db/project_test
  Replace `project_test` with the appropriate name for your application.

Next, run the rake task to create a connectable database:

$ bin/rails db:create:all

RSpec Configuration

$ bin/rails g rspec:install
  Running via Spring preloader in process 2541
  create .rspec                   ← Configuration file for RSpec
  create spec                     ← Directory for spec files
  create spec/spec_helper.rb      ← Configuration file for RSpec
  create spec/rails_helper.rb

Change the RSpec output format from the default to documentation format (optional):

.rspec
--require spec_helper
--format documentation

Verification

$ bin/rspec
Running via Spring preloader in process 56846
No examples found.
Finished in 0.00074 seconds (files took 0.144553 seconds to load)
0 examples, 0 failures

Configure Generators to Avoid Creating Unnecessary Files

config/application.rb

require_relative 'boot'

require 'rails/all'

Bundler.require(*Rails.groups)

module Projects
  class Application < Rails::Application
    config.load_defaults 5.1
    config.generators do |g|
      g.test_framework :rspec,
      view_specs: false,
      helper_specs: false,
      routing_specs: false,
      request_specs: false
    end
  end
end

Creating a Model Spec

$ bin/rails g rspec:model user

Creating a Controller Spec (Controllers are often not tested)

$ bin/rails g rspec:controller users

Adding Factories to the Application

$ bin/rails g factory_bot:model user

Creating a Feature Spec

$ bin/rails g rspec:feature users

Setup complete.