Add filename_proc option to Factory generator

features/fixture_replacement_config.feature

@@ -115,3 +115,18 @@ Feature:
       | spec/factories/users_suffix.rb |
     Then the following files should not exist:
       | spec/factories/users.rb |
+
+  Scenario: Use a filename_proc with the Factory Girl generator
+    When I add "rspec-rails" as a dependency
+    When I configure the factories as:
+      """
+      config.generators do |g|
+        g.factory_girl filename_proc: Proc.new { |tb| "prefix_#{tb.singularize}_suffix" }
+      end
+      """
+    And I run `bundle install` with a clean environment
+    And I run `bundle exec rails generate model User name:string` with a clean environment
+    Then the following files should exist:
+      | spec/factories/prefix_user_suffix.rb |
+    Then the following files should not exist:
+      | spec/factories/users.rb |

features/step_definitions/rails_steps.rb

@@ -6,19 +6,6 @@ When /^I add "([^"]+)" as a dependency$/ do |gem_name|
   append_to_file('Gemfile', %{gem "#{gem_name}"\n})
 end
 
-When /^I set the FactoryGirl :suffix option to "([^"]+)"$/ do |suffix|
-  append_to_file('config/application.rb', <<-RUBY)
-    module Testapp
-      class Application < Rails::Application
-        config.generators do |g|
-          g.fixture_replacement :factory_girl, :suffix => '#{suffix}'
-        end
-      end
-    end
-  RUBY
-
-end
-
 When /^I print out "([^"]*)"$/ do |path|
   in_current_dir do
     File.open(path, 'r') do |f|

lib/generators/factory_girl/model/model_generator.rb

@@ -48,7 +48,6 @@ module FactoryGirl
       end
 
       def create_factory_file
-        filename = [table_name, filename_suffix].compact.join('_')
         file = File.join(options[:dir], "#{filename}.rb")
         create_file(file, single_file_factory_definition)
       end
@@ -75,6 +74,14 @@ RUBY
         end.join("\n")
       end
 
+      def filename
+        if factory_girl_options[:filename_proc].present?
+          factory_girl_options[:filename_proc].call(table_name)
+        else
+          [table_name, filename_suffix].compact.join('_')
+        end
+      end
+
       def filename_suffix
         factory_girl_options[:suffix] || options[:suffix]
       end