include an email validator as seen on http://guides.rubyonrails.org/a…

…ctive_record_validations_callbacks.html#performing-custom-validations

lib/suspenders/app_builder.rb

@@ -14,7 +14,7 @@ def remove_public_images_rails
       remove_file 'public/images/rails.png'
     end
 
-    def setup_development_environment
+    def raise_delivery_errors
       replace_in_file "config/environments/development.rb", "raise_delivery_errors = false", "raise_delivery_errors = true"
     end
 
@@ -147,6 +147,10 @@ def set_attr_accessibles_on_user
         :after => /include Clearance::User\n/
     end
 
+    def add_email_validator
+      copy_file "email_validator.rb", "app/validators/email_validator.rb"
+    end
+
     def include_clearance_matchers
       create_file "spec/support/clearance.rb", "require 'clearance/testing'"
     end

lib/suspenders/generators/app_generator.rb

@@ -41,7 +41,7 @@ def remove_files_we_dont_need
 
     def setup_development_environment
       say "Setting up the development environment"
-      build(:setup_development_environment)
+      build(:raise_delivery_errors)
     end
 
     def setup_staging_environment
@@ -87,6 +87,7 @@ def configure_app
       build(:generate_cucumber)
       build(:generate_clearance)
       build(:install_factory_girl_steps)
+      build(:add_email_validator)
       build(:include_clearance_matchers)
       build(:setup_default_rake_task)
     end

templates/email_validator.rb

@@ -0,0 +1,7 @@
+class EmailValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    unless value =~ /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i
+      record.errors[attribute] << (options[:message] || "is not an email")
+    end
+  end
+end