A Rails authentication gem that takes a minimalist approach. It is designed to be simple to understand, use, and customize for your application.

Add this line to your application's Gemfile:

gem "minimalist_authentication"

And then run:

bundle

Create a user model with email for an identifier:

bin/rails generate model user active:boolean email:string password_digest:string last_logged_in_at:datetime

OR create a user model with username for an identifier:

bin/rails generate model user active:boolean username:string password_digest:string last_logged_in_at:datetime

Create a Current class that inherits from ActiveSupport::CurrentAttributes with a user attribute (app/models/current.rb)

class Current < ActiveSupport::CurrentAttributes
  attribute :user
end

Include MinimalistAuthentication::User in your user model (app/models/user.rb)

class User < ApplicationRecord
  include MinimalistAuthentication::User
end

Include MinimalistAuthentication::Controller in your ApplicationController (app/controllers/application.rb)

class ApplicationController < ActionController::Base
  include MinimalistAuthentication::Controller
end

Include MinimalistAuthentication::Sessions in your SessionsController (app/controllers/sessions_controller.rb)

class SessionsController < ApplicationController
  include MinimalistAuthentication::Sessions
end

Add session to your routes file (config/routes.rb)

Rails.application.routes.draw do
  resource :session, only: %i(new create destroy)
end

Include Minimalist::TestHelper in your test helper (test/test_helper.rb)

class ActiveSupport::TestCase
  include MinimalistAuthentication::TestHelper
end

Customize the configuration with an initializer. Create a minimalist_authentication.rb file in config/initializers.

MinimalistAuthentication.configure do |configuration|
  configuration.account_setup_duration      = 3.days              # default: 1.day
  configuration.email_verification_duration = 30.minutes          # default: 1.hour
  configuration.login_redirect_path         = :custom_path        # default: :root_path
  configuration.logout_redirect_path        = :custom_path        # default: :new_session_path
  configuration.password_reset_duration     = 30.minutes          # default: 1.hour
  configuration.request_email               = true                # default: true
  configuration.session_key                 = :custom_session_key # default: :user_id
  configuration.user_model_name             = "CustomModelName"   # default: "::User"
  configuration.validate_email              = true                # default: true
  configuration.validate_email_presence     = true                # default: true
  configuration.verify_email                = true                # default: true
end

MinimalistAuthentication.configure do |configuration|
  configuration.login_redirect_path     = :dashboard_path
  configuration.session_key             = :person_id
  configuration.user_model_name         = "Person"
  configuration.validate_email_presence = false
end

Use MinimalistAuthentication::TestHelper::PASSWORD_DIGEST to create a password_digest for fixture users.

example_user:
  email: user@example.com
  password_digest: <%= MinimalistAuthentication::TestHelper::PASSWORD_DIGEST %>

Include MinimalistAuthentication::EmailVerification in your user model (app/models/user.rb)

class User < ApplicationRecord
  include MinimalistAuthentication::User
  include MinimalistAuthentication::EmailVerification
end

Add the email_verified_at column to your user model:

bin/rails generate migration AddEmailVerifiedAtToUsers email_verified_at:datetime

Verification token support is provided by the ActiveRecord::TokenFor#generate_token_for method. MinimalistAuthentication includes token definitions for account_setup, password_reset, and email_verification.

The account_setup token is used for new users to set their initial password. The token expires in 1 day and is invalidated when the user's password is changed.

token = user.generate_token_for(:account_setup)
User.find_by_token_for(:account_setup, token) # => user
user.update!(password: "new password")
User.find_by_token_for(:account_setup, token) # => nil

The password_reset token is used for existing users to reset their password. The token expires in 1 hour and is invalidated when the user's password is changed.

token = user.generate_token_for(:password_reset)
User.find_by_token_for(:password_reset, token) # => user
user.update!(password: "new password")
User.find_by_token_for(:password_reset, token) # => nil

The email_verification token expires in 1 hour and is invalidated when the user's email is changed.

token = user.generate_token_for(:email_verification)
User.find_by_token_for(:email_verification, token) # => user
user.update!(email: "new_email@example.com")
User.find_by_token_for(:email_verification, token) # => nil

Pre 2.0 versions of MinimalistAuthentication supported multiple hash algorithms and stored the hashed password and salt as separate fields in the database (crypted_password and salt). The 2.0 version of MinimalistAuthentication uses BCrypt to hash passwords and stores the result in the password_hash field.

To convert from a pre 2.0 version add the password_hash to your user model and run the conversion routine.

bin/rails generate migration AddPasswordHashToUsers password_hash:string

MinimalistAuthentication::Conversions::MergePasswordHash.run!

When the conversion is complete the crypted_password, salt, and using_digest_version fields can safely be removed.

Version 3.0 of MinimalistAuthentication uses the Rails has_secure_password for authentication. This change requires either renaming the password_hash column to password_digest or adding an alias_attribute to map password_digest to password_hash.

Add a migration to rename the column in your users table:

bin/rails generate migration rename_users_password_hash_to_password_digest

Update the change method:

def change
  rename_column :users, :password_hash, :password_digest
end

alias_attribute :password_digest, :password_hash

The verification_token and verification_token_generated_at database columns are no longer used and can be safely removed from your user model.

The gem is available as open source under the terms of the MIT License.