make datamapper helper db agnostic.

spec/database_cleaner/data_mapper/truncation/sqlite3_spec.rb

@@ -1,8 +1,8 @@
-require 'support/data_mapper/sqlite3_helper'
+require 'support/data_mapper/data_mapper_helper'
 require 'database_cleaner/data_mapper/truncation'
 
 RSpec.describe DatabaseCleaner::DataMapper::Truncation do
-  let(:helper) { DataMapperSQLite3Helper.new }
+  let(:helper) { DataMapperHelper.new(nil, :sqlite3) }
 
   let(:connection) { helper.connection }
 

spec/support/data_mapper/data_mapper_helper.rb

@@ -2,9 +2,7 @@ require 'dm-core'
 require 'dm-sqlite-adapter'
 require 'support/database_helper'
 
-class DataMapperSQLite3Helper < DatabaseHelper
-  puts "DataMapper #{DataMapper::VERSION}, sqlite3"
-
+class DataMapperHelper < DatabaseHelper
   def setup
     super
 
@@ -31,19 +29,6 @@ class DataMapperSQLite3Helper < DatabaseHelper
 
   private
 
-  def default_config
-    db_config['sqlite3']
-  end
-
-  def create_db
-    # NO-OP
-  end
-
-  def drop_db
-    File.unlink(db_config['sqlite3']['database'])
-  rescue Errno::ENOENT
-  end
-
   def establish_connection(config = default_config)
     DataMapper.setup(:default, config)
   end