cucumber feature and example app done. Got the AR transaction strategy done as well.

cucumber.yml

@@ -0,0 +1 @@
+default: features

examples/features/support/env.rb

@@ -1,19 +1,16 @@
 require 'rubygems'
 require 'spec/expectations'
 
-require 'activerecord'
-require '../../lib/database_cleaner'
+begin
+  require "#{File.dirname(__FILE__)}/../../lib/#{ENV['ORM']}"
+rescue LoadError
+  raise "I don't have the setup for the '#{ENV['ORM']}' ORM!"
+end
+
+$:.unshift(File.dirname(__FILE__) + '/../../../lib')
+require 'database_cleaner'
 require 'database_cleaner/cucumber'
 
-DatabaseCleaner.strategy = :transaction #DatabaseCleaner::ActiveRecord::Transaction.new
+DatabaseCleaner.strategy = ENV['STRATEGY'].to_sym
 
-ActiveRecord::Base.establish_connection(:adapter => "sqlite3", :dbfile => ":memory:")
 
-ActiveRecord::Schema.define(:version => 1) do
-  create_table :widgets do |t|
-    t.string :name
-  end
-end
-
-class Widget < ActiveRecord::Base
-end

examples/lib/activerecord.rb

@@ -0,0 +1,12 @@
+require 'activerecord'
+
+ActiveRecord::Base.establish_connection(:adapter => "sqlite3", :dbfile => ":memory:")
+
+ActiveRecord::Schema.define(:version => 1) do
+  create_table :widgets do |t|
+    t.string :name
+  end
+end
+
+class Widget < ActiveRecord::Base
+end

features/cleaning.feature

@@ -1,9 +1,15 @@
-Feature: something something
-  In order to something something
-  A user something something
-  something something something
+Feature: database cleaning
+  In order to ease example and feature writing
+  As a developer
+  I want to have my database in a clean state
 
-  Scenario: something something
-    Given inspiration
-    When I create a sweet new gem
-    Then everyone should see how awesome I am
+  Scenario Outline: ruby app
+    Given I am using <ORM>
+    And the <Strategy> cleaning strategy
+
+    When I run my scenarios that rely on a clean database
+    Then I should see all green
+
+  Examples:
+    | ORM          | Strategy      |
+    | ActiveRecord | transaction   |

features/step_definitions/database_cleaner_steps.rb

@@ -0,0 +1,25 @@
+Given /^I am using (ActiveRecord|DataMapper)$/ do |orm|
+  @orm = orm
+end
+
+Given /^the (.+) cleaning strategy$/ do |strategy|
+  @strategy = strategy
+end
+
+When "I run my scenarios that rely on a clean database" do
+  full_dir ||= File.expand_path(File.dirname(__FILE__) + "/../../examples/")
+  Dir.chdir(full_dir) do
+    ENV['ORM'] = @orm.downcase
+    ENV['STRATEGY'] = @strategy
+    @out = `cucumber features`
+    @status = $?.exitstatus
+  end
+end
+
+Then "I should see all green" do
+  unless @status == 0
+    raise "Expected to see all green but we saw FAIL! Output:\n#{@out}"
+  end
+end
+
+

lib/database_cleaner/active_record/transaction.rb

@@ -1,6 +1,26 @@
 module DatabaseCleaner::ActiveRecord
   class Transaction
 
+    def start
+      if ActiveRecord::Base.connection.respond_to?(:increment_open_transactions)
+        ActiveRecord::Base.connection.increment_open_transactions
+      else
+        ActiveRecord::Base.__send__(:increment_open_transactions)
+      end
+
+      ActiveRecord::Base.connection.begin_db_transaction
+    end
+
+
+    def clean
+      ActiveRecord::Base.connection.rollback_db_transaction
+
+      if ActiveRecord::Base.connection.respond_to?(:decrement_open_transactions)
+        ActiveRecord::Base.connection.decrement_open_transactions
+      else
+        ActiveRecord::Base.__send__(:decrement_open_transactions)
+      end
+    end
   end
 
 end