Running ActiveRecord specs

active_record_helper.rb

require 'bundler/setup'
Bundler.setup(:default, :test)

require 'yaml'
require 'active_record'
require 'rspec/matchers'

require 'factory_girl'
require 'factory_girl/preload'
require 'factory_girl/preload/rspec2'

ActiveSupport::Dependencies.autoload_paths += %w[./app/models]

connection_info = YAML.load_file('config/database.yml')['test']
ActiveRecord::Base.establish_connection(connection_info)

require_relative 'support/factories'

factories.rb

FactoryGirl.define do
  factory :user do
    sequence(:email) {|n| "email#{n}@example.com" }
    password 'test'
  end

  preload do
    factory(:john) { create(:user) }
  end
end

Gemfile

source 'https://rubygems.org'

gem 'rails', '4.2.1'
gem 'sqlite3'
gem 'sass-rails', '~> 5.0'
gem 'uglifier', '>= 1.3.0'
gem 'jquery-rails'
gem 'turbolinks'
gem 'bcrypt'

group :development, :test do
  gem 'rspec-rails'
  gem 'factory_girl'
  gem 'factory_girl-preload'
  gem 'pry-meta'
end

rails_helper.rb

ENV['RAILS_ENV'] ||= 'test'
require 'spec_helper'
require File.expand_path('../../config/environment', __FILE__)
require 'rspec/rails'

Dir[Rails.root.join('spec/support/**/*.rb')].each { |f| require f }
ActiveRecord::Migration.maintain_test_schema!

RSpec.configure do |config|
  config.use_transactional_fixtures = true
  config.infer_spec_type_from_file_location!
end

user.rb

class User < ActiveRecord::Base
  has_secure_password
  validates_format_of :email, with: /\A.+@.+\..+\z/
  validates_uniqueness_of :email
end

user_spec.rb

require 'active_record_helper'

RSpec.describe User, type: :model do
  it 'requires email' do
    user = User.create(email: '')
    expect(user.errors[:email]).not_to be_empty
  end

  it 'rejects duplicated email' do
    user = User.create(email: users(:john).email)
    expect(user.errors[:email]).not_to be_empty
  end
end