Test database seeding with Minitest-rails, Capybara, Capybara-webkit and Rails 4

Question

I'm very new to TDD, and have opted to go with the above mentioned Gems. I think I have set it up correctly as I can run my tests. I can't, however, figure out how to populate my test database from db/seeds.rb. When I invoke

rake db:seed RAILS_ENV=test

in the terminal, I can see the rows created in the database through PGAdmin. However, when I run my tests with the following

rake minitest:all

the database ends up being blank afterwards, and in the test when I save a screenshot, the items from the database does not appear in the frontend as it does when I'm in dev.

My test_helper.rb contains the following.

ENV["RAILS_ENV"] = "test"
require File.expand_path("../../config/environment", __FILE__)
require "rails/test_help"
require "minitest/rails"
require 'minitest/rails/capybara'
require 'minitest/focus'
require 'minitest/colorize'
Capybara.javascript_driver = :webkit

class ActiveSupport::TestCase
  fixtures :all
    DatabaseCleaner.strategy = :transaction

    class MiniTest::Spec
      before :each do
            Rake::Task["db:seed"].invoke
            DatabaseCleaner.start
      end

      after :each do
            DatabaseCleaner.clean
      end
    end
end

And for some extra background, my db/seeds.rb file (which works when seeded from manually using rake)

ProgramIndustry.delete_all
ProgramIndustry.create([
        { name: 'Accounting and finance'},
        { name: 'Banking'},
        { name: 'Construction'},
        { name: 'Education'}
])

Why would the database not be populated with seeds.rb when the tests start?

Answer 1

Your database is blank because you are using DatabaseCleaner, which removes the data from the database. I assume this is what you want your test_helper.rb file to look like:

ENV["RAILS_ENV"] = "test"
require File.expand_path("../../config/environment", __FILE__)
require "rails/test_help"
require "minitest/rails"
require 'minitest/rails/capybara'
require 'minitest/focus'
require 'minitest/colorize'

Capybara.javascript_driver = :webkit

class ActiveSupport::TestCase
  fixtures :all

  DatabaseCleaner.strategy = :transaction

  before do
    DatabaseCleaner.start
    Rake::Task["db:seed"].invoke # seed after starting
  end

  after do
    DatabaseCleaner.clean
  end
end

I don't know about invoking the db:seed task from the before hook, that seems kinda suspect. But I don't use DatabaseCleaner, as I prefer to use fixtures and the transactions supported by ActiveSupport::TestCase.

I don't know why you are using DatabaseCleaner, but seeing as you are using RSpec syntax in Minitest, I'm assuming you are just trying things until they work. Might I suggest the dropping DatabaseCleaner and put all your test data in fixtures and using the following to manage the database transactions across threads:

ENV["RAILS_ENV"] = "test"
require File.expand_path("../../config/environment", __FILE__)
require "rails/test_help"
require "minitest/rails"
require 'minitest/rails/capybara'
require 'minitest/focus'
require 'minitest/colorize'

class ActiveSupport::TestCase
  fixtures :all
end

# Capybara driver
Capybara.javascript_driver = :webkit

# Make all database transactions use the same thread
ActiveRecord::ConnectionAdapters::ConnectionPool.class_eval do
  def current_connection_id
    Thread.main.object_id
  end
end

And if you have issues with that, consider this variation:

ENV["RAILS_ENV"] = "test"
require File.expand_path("../../config/environment", __FILE__)
require "rails/test_help"
require "minitest/rails"
require 'minitest/rails/capybara'
require 'minitest/focus'
require 'minitest/colorize'

class ActiveSupport::TestCase
  fixtures :all
end

# Capybara driver
Capybara.javascript_driver = :webkit

# Make all database transactions use the same thread
class ActiveRecord::Base
  mattr_accessor :shared_connection
  @@shared_connection = nil

  def self.connection
    @@shared_connection || retrieve_connection
  end
end

ActiveRecord::Base.shared_connection = ActiveRecord::Base.connection