Add test for generator

lib/generators/paperclip/paperclip_generator.rb

@@ -29,5 +29,4 @@ class PaperclipGenerator < ActiveRecord::Generators::Base
   def migration_class_name
     migration_name.camelize
   end
-
 end

test/generator_test.rb

+require './test/helper'
+require 'rails/generators'
+require 'generators/paperclip/paperclip_generator'
+
+class GeneratorTest < Rails::Generators::TestCase
+  tests PaperclipGenerator
+  destination File.expand_path("../tmp", File.dirname(__FILE__))
+  setup :prepare_destination
+
+  context 'running migration' do
+    context 'with single attachment name' do
+      setup do
+        run_generator %w(user avatar)
+      end
+
+      should 'create a correct migration file' do
+        assert_migration 'db/migrate/add_attachment_avatar_to_user.rb' do |migration|
+          assert_match /class AddAttachmentAvatarToUser/, migration
+
+          assert_class_method :up, migration do |up|
+            assert_match /add_column :users, :avatar_file_name, :string/, up
+            assert_match /add_column :users, :avatar_content_type, :string/, up
+            assert_match /add_column :users, :avatar_file_size, :integer/, up
+            assert_match /add_column :users, :avatar_updated_at, :datetime/, up
+          end
+
+          assert_class_method :down, migration do |down|
+            assert_match /remove_column :users, :avatar_file_name/, down
+            assert_match /remove_column :users, :avatar_content_type/, down
+            assert_match /remove_column :users, :avatar_file_size/, down
+            assert_match /remove_column :users, :avatar_updated_at/, down
+          end
+        end
+      end
+    end
+
+    context 'with multiple attachment names' do
+      setup do
+        run_generator %w(user avatar photo)
+      end
+
+      should 'create a correct migration file' do
+        assert_migration 'db/migrate/add_attachment_avatar_photo_to_user.rb' do |migration|
+          assert_match /class AddAttachmentAvatarPhotoToUser/, migration
+
+          assert_class_method :up, migration do |up|
+            assert_match /add_column :users, :avatar_file_name, :string/, up
+            assert_match /add_column :users, :avatar_content_type, :string/, up
+            assert_match /add_column :users, :avatar_file_size, :integer/, up
+            assert_match /add_column :users, :avatar_updated_at, :datetime/, up
+            assert_match /add_column :users, :photo_file_name, :string/, up
+            assert_match /add_column :users, :photo_content_type, :string/, up
+            assert_match /add_column :users, :photo_file_size, :integer/, up
+            assert_match /add_column :users, :photo_updated_at, :datetime/, up
+          end
+
+          assert_class_method :down, migration do |down|
+            assert_match /remove_column :users, :avatar_file_name/, down
+            assert_match /remove_column :users, :avatar_content_type/, down
+            assert_match /remove_column :users, :avatar_file_size/, down
+            assert_match /remove_column :users, :avatar_updated_at/, down
+            assert_match /remove_column :users, :photo_file_name/, down
+            assert_match /remove_column :users, :photo_content_type/, down
+            assert_match /remove_column :users, :photo_file_size/, down
+            assert_match /remove_column :users, :photo_updated_at/, down
+          end
+        end
+      end
+    end
+
+    context 'without required arguments' do
+      should 'not create the migration' do
+        silence_stream(STDERR) { run_generator %w() }
+        assert_no_migration 'db/migrate/add_attachment_avatar_to_user.rb'
+      end
+    end
+  end
+end