Allow to run migrations with given scope, with SCOPE=<scope>

Scope in migrations can be defined by adding suffix in filename,
like: 01_a_migration.blog.rb. Such migration have blog scope.

Scope is automatically added while copying migrations from engine,
so if you want to revert all of the migrations from given engine,
you can just run db:migrate with SCOPE, like:

    rake db:migrate SCOPE=blog

1 files changed, 24 insertions, 0 deletions

diff --git a/railties/test/application/rake/migrations_test.rb b/railties/test/application/rake/migrations_test.rb
index 4ec6f1b67c..3d3e01cdc0 100644
--- a/railties/test/application/rake/migrations_test.rb
+++ b/railties/test/application/rake/migrations_test.rb
@@ -12,6 +12,30 @@ module ApplicationTests
       def teardown
         teardown_app
       end
+
+      test 'running migrations with given scope' do
+        Dir.chdir(app_path) do
+          `rails generate model user username:string password:string`
+        end
+        app_file "db/migrate/01_a_migration.bukkits.rb", <<-MIGRATION
+          class AMigration < ActiveRecord::Migration
+          end
+        MIGRATION
+
+        output = Dir.chdir(app_path) { `rake db:migrate SCOPE=bukkits` }
+        assert_no_match(/create_table\(:users\)/, output)
+        assert_no_match(/CreateUsers/, output)
+        assert_no_match(/add_column\(:users, :email, :string\)/, output)
+
+        assert_match(/AMigration: migrated/, output)
+
+        output = Dir.chdir(app_path) { `rake db:migrate SCOPE=bukkits VERSION=0` }
+        assert_no_match(/drop_table\(:users\)/, output)
+        assert_no_match(/CreateUsers/, output)
+        assert_no_match(/remove_column\(:users, :email\)/, output)
+
+        assert_match(/AMigration: reverted/, output)
+      end
       
       test 'model and migration generator with change syntax' do
          Dir.chdir(app_path) do