added clean_with shortcut method

lib/database_cleaner/configuration.rb

@@ -23,6 +23,12 @@ module DatabaseCleaner
       orm_strategy(strategy).new(*strategy_args)
     end
 
+    def clean_with(*args)
+      strategy = create_strategy(*args)
+      strategy.clean
+      strategy
+    end
+
     def strategy=(args)
       strategy, *strategy_args = args
        if strategy.is_a?(Symbol)

spec/database_cleaner/configuration_spec.rb

@@ -22,7 +22,7 @@ describe DatabaseCleaner do
   end
 
   describe ".create_strategy ( DatabaseCleaner() )" do
-    it "should initialize and return the appropirate strategy based on the ORM adapter detected" do
+    it "should initialize and return the appropirate strategy" do
       DatabaseCleaner::ActiveRecord::Transaction.should_receive(:new).with('options' => 'hash')
       result = DatabaseCleaner(:transaction, {'options' => 'hash'})
 
@@ -30,6 +30,15 @@ describe DatabaseCleaner do
     end
   end
 
+  describe ".clean_with" do
+    it "should initialize the appropirate strategy and clean with it" do
+      DatabaseCleaner::ActiveRecord::Transaction.should_receive(:new).with('options' => 'hash')
+      @strategy.should_receive(:clean)
+
+      DatabaseCleaner.clean_with(:transaction, 'options' => 'hash')
+    end
+  end
+
   describe ".strategy=" do
     it "should initialize the appropirate strategy based on the ORM adapter detected" do
       DatabaseCleaner::ActiveRecord::Transaction.should_receive(:new).with('options' => 'hash')