create_user.rb

require 'spec_helper'
require 'faker'

feature 'Create user' do
  scenario 'creates a user successfully with a valid username, email and password' do
    register_with Faker::Internet.user_name, 'test123', 'test123', Faker::Internet.email
    user_sees_success_message "Registered successfully!"
  end

  scenario 'notifies the user if his username is invalid' do
    register_with nil, 'test123', 'test123', Faker::Internet.email
    user_sees_error_message "Username can't be blank"
  end

  scenario 'notifies the user if his username is to short' do
    register_with 'el', 'test123', 'test123', Faker::Internet.email
    user_sees_error_message "Username is too short (minimum is 3 characters)"
  end

  scenario 'notifies the user if his email is invalid' do
    register_with Faker::Internet.user_name, 'test123', 'test123', nil
    user_sees_error_message "Email can't be blank"
  end

  scenario 'notifies the user if his password is to short' do
    register_with Faker::Internet.user_name, 'test', 'test', Faker::Internet.email
    user_sees_error_message "Password is too short (minimum is 6 characters)"
  end

  scenario 'notifies the user if his password doesnt match' do
    register_with Faker::Internet.user_name, 'test123', 'test321', Faker::Internet.email
    user_sees_error_message "Password confirmation doesn't match Password"
  end

  def user_sees_error_message(message)
    expect(page).to have_css '.error_messages', message
  end

  def user_sees_success_message(message)
    expect(page).to have_css '.notice', message
  end

  def register_with(username, password, password_confirm, email)
    visit new_user_path
    fill_in 'Username', with: username
    fill_in 'Password', with: password
    fill_in 'Password confirmation', with: password_confirm
    fill_in 'Email', with: email
    click_button 'Register'
  end
end

sign_in_spec.rb

require 'spec_helper'
require 'faker'

feature 'Signing in' do
  background do
    @email = '[email protected]'
    @password = 'test123'
    @user = create(:user, username: 'ellen.u', email: @email, password: @password, password_confirmation: @password)
  end

  scenario 'signs the user in successfully with a valid email and password' do
    sign_in_with(@email, @password)
    user_sees_success_message 'Logged in!'
  end

  scenario 'notifies the user if his email or password is invalid' do
    sign_in_with(Faker::Internet.email, Faker::Internet.password)
    user_sees_error_message 'Invalid email or password'
  end
  

  def user_sees_error_message(message)
    expect(page).to have_css '.alert', message
  end

  def user_sees_success_message(message)
    expect(page).to have_css '.notice', message
  end

  def sign_in_with(email, password)
    visit session_path
    fill_in 'Email', with: email
    fill_in 'Password', with: password
    click_button 'Login'
  end
end

sign_out_spec.rb

require 'spec_helper'
require 'faker'

feature 'Signing out' do
  background do
    @user = create(:user, username: 'ellen.u', email: '[email protected]', password: 'test123', password_confirmation: 'test123')
  end

  scenario 'signs the user out successfully' do
    login_user(@user)
    logout_user
    user_sees_success_message 'Logged out!'
  end

  def user_sees_error_message(message)
    expect(page).to have_css '.alert', message
  end

  def user_sees_success_message(message)
    expect(page).to have_css '.notice', message
  end

  def login_user(user)
    visit session_path
    fill_in 'Email', with: user.email
    fill_in 'Password', with: user.password
    click_button 'Login'
  end

  def logout_user
    visit root_path
    click_link 'Logout'
  end
end

user.rb

class User < ActiveRecord::Base
  has_many :posts
  has_many :topics
  has_secure_password

  validates :password, length: { minimum: 6 }
  validates :username, presence: true, uniqueness: true, length: { minimum: 3 }
  validates :email, presence: true, uniqueness: true
end

user_spec.rb

require 'spec_helper'

describe User do
  it "is valid if all parameters match" do
    build(:user).should be_valid
  end

  it { should have_secure_password }

  it { should validate_presence_of(:email) }

  it { should ensure_length_of(:username).is_at_least(3) }

  it { should ensure_length_of(:password).is_at_least(6) }

  it do
    should validate_confirmation_of(:password)
  end

  it { should validate_uniqueness_of(:username) }

  it { should validate_uniqueness_of(:email) }
end

users.rb

require 'faker'
FactoryGirl.define do
  factory :user do 
    email {Faker::Internet.email}
    username {Faker::Internet.user_name}
    first_name {Faker::Name.first_name}
    last_name {Faker::Name.last_name}
    password 'test123'
    password_confirmation 'test123'
  end
end