Testing with rspec and capybara in rails

We’re supposing, you’ve a rails app already working. Now you want to write test cases for testing your rails app. Let’s see how to do.

Add gem 'rspec-rails' to your Gemfile in the :development, :test group.

group :development, :test do
    ...
    gem 'rspec-rails', '~> 3.8', '>= 3.8.2'
end

1. In the terminal window, run bundle install
2. In the terminal window, run rails generate rspec:install .
3. Add gem 'factory_bot_rails' to your Gemfile in the :development, :test group.

group :development, :test do
  ...
  gem 'rspec-rails', '~> 3.8', '>= 3.8.2'
  gem 'factory_bot_rails', '~> 5.1'
end

the terminal window, run bundle install

1. Create a new directory at mkdir spec/factories/ by running mkdir spec/factories in the terminal window. This is required by factory_bot_rails
2. Create a new directory at spec/support/ by running mkdir spec/support in the terminal window
3. Create factory_bot.rb in spec/support by running touch spec/support/factory_bot.rb in the terminal window
4. Open spec/support/factory_bot.rb and add the following:

RSpec.configure do |config|
    config.include FactoryBot::Syntax::Methods
end

Add gem 'capybara' to your Gemfile in the :development, :test group.

group :development, :test do
  ...
  gem 'rspec-rails', '~> 3.8', '>= 3.8.2'
  gem 'factory_bot_rails', '~> 5.1'
  gem 'capybara', '~> 3.29'
end

1. In the terminal window, run bundle install
2. Create capybara.rb in spec/support by running touch spec/support/capybara.rb in the terminal window
3. Open spec/support/capybara.rb and add the following:

require 'capybara/rspec'

1. Add gem 'database_cleaner' to your Gemfile in the :test group.

group :test do
  gem 'database_cleaner', '~> 1.7'end

1. In the terminal window, run bundle install
2. Open spec/support/capybara.rb and add the following:

require 'capybara/rspec'
RSpec.configure do |config|
  config.use_transactional_fixtures = false 
  config.before(:suite) do
    if config.use_transactional_fixtures?
        raise(<<-MSG)
          Delete line `config.use_transactional_fixtures = true`
          from rails_helper.rb (or set it to false) to prevent
          uncommitted transactions being used in JavaScript-
          dependent specs.
          During testing, the app-under-test that the browser driver
          connects to uses a different database connection to the
          database connection used by the spec. The app's database
          connection would not be able to access uncommitted       
          transaction data setup over the spec's database
          connection.
        MSG
    end
    DatabaseCleaner.clean_with(:truncation)
  end
  config.before(:each) do
    DatabaseCleaner.strategy = :transaction 
  end
  config.before(:each, type: :feature) do
    driver_shares_db_connection_with_specs = Capybara.current_driver
    == :rack_test
    unless driver_shares_db_connection_with_specs
      DatabaseCleaner.strategy = :truncation    
    end  
  end     
 config.before(:each) do
  DatabaseCleaner.start   
 end     
 config.append_after(:each) do    
  DatabaseCleaner.clean   
 end  
end

Create Our First Test (Optional)

Now that our app’s test suite is configured with RSpec, Capybara, Factory Bot Rails and Database Cleaner, let’s write some tests to ensure everything is working.

In the terminal window, run rails db:migrate RAILS_ENV=test — traceto migrate the database. I’ve a user model already with following association in app/models/user.rb .

has_many :businesses, -> { distinct} , through: :memberships, dependent: :destroy

And business model with following validation in app/models/business.rb .

validates :name, :phone, :address1, :city, :state, :zip, :country,  presence: true

And a scope businesses to fined user’s approved business

scope :businesses, -> do
  where(approved: true)
end

Now generatespec/models/business_spec.rb by running following command:

rails generate rspec:model business

Update spec/models/business_spec.rb with the following code:

require 'rails_helper'
RSpec.describe Business, type: :model do
  context 'business scope test' do
    before(:each) do
      Business.new(name: 'Test1', phone: '12345678', address1: 'Test
      Address-1', city: 'Test City-1', state: 'Test State-1', zip:
      '1234', country: 'Test Country-1').save!
      Business.new(name: 'Test2', phone: '12345678', address1: 'Test
      Address-2', city: 'Test City-2', state: 'Test State-2', zip:
      '1234', country: 'Test Country-2', approved:true).save!
      Memberships.create(user_id: 2, business_id: Business.first.id)
    end
    it 'should return approved businesses for a user' do
      expect(User.second.businesses.size).to eq(1)
    end
  end
end

Run rspec. It will first create two business, one with approved: true and one will have approved: false by default. Then it will create a membership of second user for first business in our database. Then it will retrieve all businesses of second user with approved: true which counts to 1.