Allow override for finding record during session creation

README.md

@@ -16,6 +16,7 @@ Add authentication to your Rails app without all the icky-ness of passwords.
 * [Usage](#usage)
      * [Getting the current user, restricting access, the usual](#getting-the-current-user-restricting-access-the-usual)
      * [Providing your own templates](#providing-your-own-templates)
+     * [Overrides](#overrides)
      * [Registering new users](#registering-new-users)
      * [Generating tokens](#generating-tokens)
      * [Redirecting back after sign-in](#redirecting-back-after-sign-in)
@@ -51,7 +52,7 @@ Then specify which field on your `User` record is the email field with:
 ```ruby
 class User < ApplicationRecord
   validates :email, presence: true, uniqueness: { case_sensitive: false }
-  
+
   passwordless_with :email # <-- here!
 end
 ```
@@ -73,13 +74,13 @@ Passwordless doesn't give you `current_user` automatically -- it's dead easy to
 ```ruby
 class ApplicationController < ActionController::Base
   include Passwordless::ControllerHelpers # <-- This!
-  
+
   # ...
-  
+
   helper_method :current_user
-  
+
   private
-  
+
   def current_user
     @current_user ||= authenticate_by_cookie(User)
   end
@@ -96,7 +97,7 @@ Et voilà:
 ```ruby
 class VerySecretThingsController < ApplicationController
   before_action :require_user!
-  
+
   def index
     @things = current_user.very_secret_things
   end
@@ -118,6 +119,25 @@ app/views/passwordless/mailer/magic_link.text.erb
 
 See [the bundled views](https://github.com/mikker/passwordless/tree/master/app/views/passwordless).
 
+### Overrides
+
+By default `passwordless` uses the `passwordless_with` column you specify in the model to case insensitively fetch the resource during authentication. You can override this and provide your own customer fetcher by defining a class method `fetch_resource_for_passwordless` in your passwordless model. The method will be supplied with the downcased email and should return an `ActiveRecord` instance of the model.
+
+Example time:
+
+Let's say we would like to fetch the record and if it doesn't exist, create automatically.
+
+```ruby
+    class User < ApplicationRecord
+        def self.fetch_resource_for_passwordless(email)
+            record = where("lower(email) = ?", email).first
+            return record if record.present?
+
+            create(email: email)
+        end
+    end
+```
+
 ### Registering new users
 
 Because your `User` record is like any other record, you create one like you normally would. Passwordless provides a helper method you can use to sign in the created user after it is saved like so:
@@ -129,15 +149,15 @@ class UsersController < ApplicationController
 
   def create
     @user = User.new user_params
-    
+
     if @user.save
       sign_in @user # <-- And this!
       redirect_to @user, flash: {notice: 'Welcome!'}
     else
       render :new
     end
   end
-  
+
   # ...
 end
 ```
@@ -161,9 +181,9 @@ By default Passwordless will redirect back to where the user wanted to go **if**
 ```ruby
 class ApplicationController < ActionController::Base
   include Passwordless::ControllerHelpers # <-- Probably already have this!
-  
+
   # ...
-  
+
   def require_user!
     return if current_user
     save_passwordless_redirect_location!(User) # <-- here we go!
@@ -181,7 +201,7 @@ By default, Passwordless uses the resource name given to `passwordless_for` to g
 ```ruby
 passwordless_for :users
   # <%= users.sign_in_path %> # => /users/sign_in
-  
+
 passwordless_for :users, at: '/', as: :auth
   # <%= auth.sign_in_path %> # => /sign_in
 ```

app/controllers/passwordless/sessions_controller.rb

@@ -90,9 +90,15 @@ def email_field
     end
 
     def find_authenticatable
-      authenticatable_class.where(
-        "lower(#{email_field}) = ?", params[:passwordless][email_field].downcase
-      ).first
+      email = params[:passwordless][email_field].downcase
+
+      if authenticatable_class.respond_to?(:fetch_resource_for_passwordless)
+        authenticatable_class.fetch_resource_for_passwordless(email)
+      else
+        authenticatable_class.where(
+          "lower(#{email_field}) = ?", params[:passwordless][email_field].downcase
+        ).first
+      end
     end
 
     def find_session

test/controllers/passwordless/sessions_controller_test.rb

@@ -12,6 +12,12 @@ def create_session_for(user)
       )
     end
 
+    def User.fetch_resource_for_passwordless(email)
+      return if email == 'invalidemail'
+
+      User.find_or_create_by(email: email)
+    end
+
     test 'requesting a magic link as an existing user' do
       User.create email: 'a@a'
 
@@ -31,13 +37,25 @@ def create_session_for(user)
       assert_equal 200, status
 
       post '/users/sign_in',
-        params: { passwordless: { email: 'something_em@ilish' } },
+        params: { passwordless: { email: 'invalidemail' } },
         headers: { 'User-Agent': 'an actual monkey' }
       assert_equal 200, status
 
       assert_equal 0, ActionMailer::Base.deliveries.size
     end
 
+    test 'requesting a magic link with overridden fetch method' do
+      get '/users/sign_in'
+      assert_equal 200, status
+
+      post '/users/sign_in',
+        params: { passwordless: { email: 'overriden_email@example' } },
+        headers: { 'User-Agent': 'an actual monkey' }
+      assert_equal 200, status
+
+      assert_equal 1, ActionMailer::Base.deliveries.size
+    end
+
     test 'signing in via a token' do
       user = User.create email: 'a@a'
       session = create_session_for user