Add more spec for rake task db:rollback

Author: PikachuEXE

spec/lib/sequel_rails/railties/database_rake_spec.rb

@@ -82,11 +82,20 @@
   end
 
   describe 'db:rollback' do
+    let(:version) { nil }
+    let(:rake_task_call) do
+      if version
+        proc { `rake db:rollback VERSION=#{version}` }
+      else
+        proc { `rake db:rollback` }
+      end
+    end
+
     it 'revert latest migration' do
       Dir.chdir app_root do
         begin
           expect do
-            `rake db:rollback`
+            rake_task_call.call
           end.to change { SequelRails::Migrations.current_migration }.from(
             '1365762739_add_github_username_to_users.rb'
           ).to('1365762738_add_display_name_to_users.rb')
@@ -95,6 +104,58 @@
         end
       end
     end
+
+    context 'when version supplied' do
+      context 'same as current version' do
+        let(:version) { '1365762739' }
+
+        it 'does not revert' do
+          Dir.chdir app_root do
+            begin
+              expect do
+                rake_task_call.call
+              end.not_to change { SequelRails::Migrations.current_migration }
+            ensure
+              SequelRails::Migrations.migrate_up!
+            end
+          end
+        end
+      end
+      context 'same as last version' do
+        let(:version) { '1365762738' }
+
+        it 'revert latest migration' do
+          Dir.chdir app_root do
+            begin
+              expect do
+                rake_task_call.call
+              end.to change { SequelRails::Migrations.current_migration }.from(
+                '1365762739_add_github_username_to_users.rb'
+              ).to('1365762738_add_display_name_to_users.rb')
+            ensure
+              SequelRails::Migrations.migrate_up!
+            end
+          end
+        end
+      end
+      context 'smaller than last version' do
+        let(:version) { '1273253849' }
+
+        it 'revert until migration specified by version' do
+          Dir.chdir app_root do
+            begin
+              expect do
+                rake_task_call.call
+              end.to change { SequelRails::Migrations.current_migration }.from(
+                '1365762739_add_github_username_to_users.rb'
+              ).to('1273253849_add_twitter_handle_to_users.rb')
+            ensure
+              SequelRails::Migrations.migrate_up!
+            end
+          end
+        end
+      end
+    end
   end
 
   describe 'db:migrate:redo' do