test.diff

diff --git a/activerecord/test/cases/adapters/postgresql/hstore_test.rb b/activerecord/test/cases/adapters/postgresql/hstore_test.rb
index 6df5d8f..8d1e7bc 100644
--- a/activerecord/test/cases/adapters/postgresql/hstore_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/hstore_test.rb
@@ -70,6 +70,23 @@ class PostgresqlHstoreTest < ActiveRecord::TestCase
       Hstore.reset_column_information
     end
 
+    def test_adding_hstore_column_is_revertable
+      hstore_migration = Class.new(ActiveRecord::Migration) do
+        def write(text = '')
+        end
+
+        def change
+          add_column 'hstores', 'groups', :hstore
+        end
+      end
+
+      migration = hstore_migration.new
+      migration.migrate(:up)
+      assert_equal ["id", "tags", "settings", "groups"], @connection.columns("hstores").map(&:name)
+      migration.migrate(:down)
+      assert_equal ["id", "tags", "settings"], @connection.columns("hstores").map(&:name)
+    end
+
     def test_cast_value_on_write
       x = Hstore.new tags: {"bool" => true, "number" => 5}
       assert_equal({"bool" => "true", "number" => "5"}, x.tags)