Monban is currently in the process of being renamed Oath: https://github.com/halogenandtoast/oath

Oath is designed to be a very simple and extensible user authentication library for rails. Its goal is to give all the power to the developer instead of forcing them to make Oath work with their system.

Oath makes authentication simple:

• Easy to use in tests with dependency injection
• Provides convenient controller helpers
• Very customizable

Oath doesn't do the following:

• Doesn't automatically add routes to your application
• Doesn't force you to use engine based controllers or views
• Doesn't require you to make changes to your user model

You can read the full documentation at rubydoc

Oath was designed to work with Rails > 4.0. Add this line to your Gemfile:

gem 'oath'

Then inside of your ApplicationController add the following:

include Oath::ControllerHelpers

And you're ready to start designing your authentication system.

If you'd like a good starting point for building an app using Oath, it is suggested to use the oath generators

Oath does currently have some out-of-the-box expectations, but you can configure and change any of these:

• By default the model should be called User
• Oath expects your user model to respond to create, id, and find_by
• You should have an email and password_digest column on your User
• Passwords will be handled with BCrypt

If you're trying to sign up a User in a console you won't be able to call User#new or User#create because the User model does not know how to encrypt passwords. You should instead use the sign up service in order to create the user:

Oath.config.sign_up_service.new(email: "foo@example.com", password: "password").perform

Oath doesn't add validations to your user model unless you're using oath generators so it's suggested to add the following validations:

validates :email, presence: true, uniqueness: true
validates :password_digest, presence: true

In addition to that you'll want to add the following to your config/locale/en.yml:

en:
  activerecord:
    attributes:
      user:
        password_digest: "Password"

Which will generate the error message Password can't be blank instead of Password digest can't be blank.

It is suggested you add something like this to your application layout:

<% if signed_in? %>
  <%= link_to "Sign out", session_path, method: :delete %>
<% else %>
  <%= link_to "Sign in", new_session_path %>
  <%= link_to "Sign up", new_user_path %>
<% end %>

If you want to introduce a Guest object when a user is not signed in, you can override Oath's current_user method in your ApplicationController:

def current_user
  super || Guest.new
end

In app/models/, define a Guest class:

class Guest
  def name
    "Guest"
  end
end

This article on the Null Object Pattern provides a good explanation of why you might want to do this.

If you want to use I18n for the notice instructing users to sign in when they try to access an unauthorized page you can do so with the following configuration:

Oath.configure do |config|
  config.sign_in_notice = -> { I18n.t("sign_in_notice") }
end

It is suggested to store this file at config/initializers/oath.rb

Oath provides the following controller methods:

• sign_in(user)
• sign_out
• sign_up(user_params)
• authenticate(user, password)
• authenticate_session(session_params)
• reset_password(user, password)

These helpers:

• current_user
• signed_in?

And this filter:

• require_login

To authorize users in config/routes.rb:

require "oath/constraints/signed_in"
require "oath/constraints/signed_out"

Blog::Application.routes.draw do
  constraints Oath::Constraints::SignedIn.new do
    root "dashboards#show", as: :dashboard
  end

  constraints Oath::Constraints::SignedOut.new do
    root "landings#show"
  end
end

Oath provides the following:

Oath.test_mode!

Which will change password hashing method to provide plaintext responses instead of using BCrypt. This will allow you to write factories using the password_digest field:

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

A couple of convenience methods are available in your tests. In order to set this up you'll want to add the following to rails_helper.rb or if that doesn't exist spec_helper.rb

Oath.test_mode!

RSpec.configure do |config|
  config.include Oath::Test::Helpers, type: :feature
  config.after :each do
    Oath.test_reset!
  end
end

Then you can use any of the test helpers in your scenarios

feature "A feature spec" do
  scenario "that requires login" do
    user = create(:user)
    sign_in(user)
    # do something
    sign_out
    # do something else
  end
end

Similar to clearance's backdoor you can visit a path and sign in quickly via

user = create(:user)
visit dashboard_path(as: user)

To enable this functionality you'll want to add the following to config/environments/test.rb:

config.middleware.insert_after Warden::Manager, Oath::BackDoor

If you'd like to find your User model by a field other than id, insert the middleware with a block that accepts the as query parameter and returns an instance of your User model:

config.middleware.insert_after Warden::Manager, Oath::BackDoor do |user_param|
  User.find_by(username: user_param)
end

If you are going to write controller tests, helpers are provided for those as well:

Oath.test_mode!

RSpec.configure do |config|
  config.include Oath::Test::ControllerHelpers, type: :controller
  config.after :each do
    Oath.test_reset!
  end
end

require 'spec_helper'

describe ProtectedController do

  describe "GET 'index'" do
    it "returns http success when signed in" do
      user = create(:user)
      sign_in(user)
      get 'index'
      response.should be_success
    end

    it "redirects when not signed in" do
      get 'index'
      response.should be_redirect
    end
  end
end

If you want to sign in with username instead of email just change the configuration option

# config/initializers/oath.rb
Oath.configure do |config|
  config.user_lookup_field = :username
end

If you used the oath:scaffold generator from oath generators you'll have to change the following four references to email.

• In SessionsController#session_params
• In UsersController#user_params
• The email form field on sessions#new
• The email form field on users#new

You may perform a look up on a user using multiple fields by doing something like the following:

class SessionsController < ApplicationController
  def create
    user = authenticate_session(session_params, email_or_username: [:email, :username])

    if sign_in(user)
      redirect_to(root_path)
    else
      render :new
    end
  end

  private

  def session_params
    params.require(:session).permit(:email_or_username, :password)
  end

end

This will allow the user to enter either their username or email to login

Oath::Configuration has lots of options for changing how oath works. Currently the options you can change are as follows:

• user_lookup_field: (default :email) Field in the database to lookup a user by.
• user_token_field: (default :password) Field the form submits containing the undigested password.
• user_token_store_field: (default: :password_digest) Field in the database that stores the user's digested password.
• user_class: (default: 'User') The user class.

• sign_in_notice: (default: You must be signed in) Rails flash message to set when user signs in.
• sign_in_service: (default: Oath::Services::SignIn) Service for signing a user in.
• sign_up_service: (default: Oath::Services::SignUp) Service for signing a user up.
• sign_out_service: (default: Oath::Services::SignOut) Service for signing a user out.
• authentication_service: (default: Oath::Services::Authentication) Service for authenticated a user.
• password_reset_service: (default: Oath::Services::PasswordReset) Service for resetting a user's password.

• no_login_handler: A before_action for rails that handles when a user is not signed in.
• no_login_redirect: Used by the no_login_handler to redirect the user

• hashing_method: Method to hash an undigested password.
• token_comparison: Method to compare a digested and undigested password.
• creation_method: Method for creating a user.
• find_method: Method for finding a user.

• failure_app: Necessary for warden to work. A rack app that handles failures in authentication.

Here are a few of the current limitations of oath:

• Oath assumes you only have one user model.

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request