When using database_authenticatable Devise will now only create an email field when appropriate.

(If using default authentication_keys or custom authentication_keys with email included)

Test written for Mongoid, not sure how to test for active_record yet.

lib/devise/schema.rb

@@ -3,7 +3,7 @@ module Devise
   # and overwrite the apply_schema method.
   module Schema
 
-    # Creates email, encrypted_password and password_salt.
+    # Creates email when enabled (on by default), encrypted_password and password_salt.
     #
     # == Options
     # * :null - When true, allow columns to be null.
@@ -15,8 +15,10 @@ module Devise
     def database_authenticatable(options={})
       null    = options[:null] || false
       default = options.key?(:default) ? options[:default] : ("" if null == false)
+      include_email =  !self.respond_to?(:authentication_keys) \
+                       || (self.respond_to?(:authentication_keys) && self.authentication_keys.include?(:email))
 
-      apply_devise_schema :email,              String, :null => null, :default => default
+      apply_devise_schema :email,              String, :null => null, :default => default if include_email
       apply_devise_schema :encrypted_password, String, :null => null, :default => default, :limit => 128
     end
 

test/schema_test.rb

@@ -0,0 +1,21 @@
+require 'test_helper'
+
+class SchemaTest < ActiveSupport::TestCase
+  if DEVISE_ORM == :mongoid 
+    test 'should create an email field if there are no custom authentication keys' do
+      eval "class User2; include Mongoid::Document; devise :database_authenticatable; end"
+      assert_not_equal User2.fields['email'], nil
+    end
+
+    test 'should create an email field if there are custom authentication keys and they include email' do
+      eval "class User3; include Mongoid::Document; devise :database_authenticatable, :authentication_keys => [:username, :email]; end"
+      assert_not_equal User3.fields['email'], nil
+    end
+    
+    test 'should not create an email field if there are custom authentication keys they don\'t include email' do
+      eval "class User4; include Mongoid::Document; devise :database_authenticatable, :authentication_keys => [:usernames]; end"
+      assert_equal User4.fields['email'], nil
+      assert_equal User4.fields['username'], nil
+    end
+  end
+end