Database cleaner configuration for rails applications

database_cleaner.rb

# frozen_string_literal: true

require 'database_cleaner'

RSpec.configure do |config|
  config.use_transactional_fixtures = false

  config.before(:suite) do
    if config.use_transactional_fixtures?

      raise(<<-MSG)
			Comment 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 Ruby app server that the JavaScript browser driver
			connects to uses a different database connection to the database connection
			used by the spec.
			This Ruby app server database connection would not be able to see data that
			has been setup by the spec's database connection inside an uncommitted
			transaction.
			Disabling the use_transactional_fixtures setting helps avoid uncommitted
			transactions in JavaScript-dependent specs, meaning that the Ruby app server
			database connection can see any data set up by the specs.
			MSG

    end
  end

  config.before(:suite) do
    DatabaseCleaner.clean_with(:truncation)
  end

  config.before(:each) do
    DatabaseCleaner.strategy = :transaction
  end

  config.before(:each, type: :feature) do
    # :rack_test driver's Rack app under test shares database connection
    # with the specs, so we can use transaction strategy for speed.
    driver_shares_db_connection_with_specs = Capybara.current_driver == :rack_test

    DatabaseCleaner.strategy = if driver_shares_db_connection_with_specs
                                 :transaction
                               else
                                 # Non-:rack_test driver is probably a driver for a JavaScript browser
                                 # with a Rack app under test that does *not* share a database
                                 # connection with the specs, so we must use truncation strategy.
                                 :truncation
                               end
  end

  config.before(:each) do
    DatabaseCleaner.start
  end

  config.after(:each) do
    DatabaseCleaner.clean
  end
end