refactor datamapper sqlite3 test helper to inherit from DatabaseHelper.

spec/database_cleaner/data_mapper/truncation/sqlite3_spec.rb

@@ -1,38 +1,30 @@
-require 'dm-core'
-require 'dm-sqlite-adapter'
-require 'support/data_mapper/sqlite3_setup'
+require 'support/data_mapper/sqlite3_helper'
 require 'database_cleaner/data_mapper/truncation'
 
 RSpec.describe DatabaseCleaner::DataMapper::Truncation do
   let(:helper) { DataMapperSQLite3Helper.new }
 
-  let(:connection) do
-    helper.data_mapper_sqlite3_connection
-  end
+  let(:connection) { helper.connection }
 
   around do |example|
-    helper.data_mapper_sqlite3_setup
-
+    helper.setup
     example.run
-
-    helper.data_mapper_sqlite3_teardown
+    helper.teardown
   end
 
   describe "DM connection adapter monkeypatches" do
+    before do
+      2.times { DmUser.create }
+    end
+
     describe "#truncate_table" do
       it "truncates the table" do
-        2.times { DmUser.create }
-
         connection.truncate_table(DmUser.storage_names[:default])
         expect(DmUser.count).to eq 0
       end
 
       it "resets AUTO_INCREMENT index of table" do
-        2.times { DmUser.create }
-        DmUser.destroy
-
         connection.truncate_table(DmUser.storage_names[:default])
-
         expect(DmUser.create.id).to eq 1
       end
     end

spec/support/data_mapper/schema_setup.rb

@@ -1,15 +0,0 @@
-def data_mapper_load_schema
-  require 'dm-migrations'
-
-  DataMapper.auto_migrate!
-end
-
-class ::DmUser
-  include DataMapper::Resource
-
-  self.storage_names[:default] = 'users'
-
-  property :id, Serial
-  property :name, String
-
-end

spec/support/data_mapper/sqlite3_helper.rb

@@ -0,0 +1,35 @@
+require 'dm-core'
+require 'dm-sqlite-adapter'
+require 'support/database_helper'
+
+class ::DmUser
+  include DataMapper::Resource
+
+  self.storage_names[:default] = 'users'
+
+  property :id, Serial
+  property :name, String
+end
+
+class DataMapperSQLite3Helper < DatabaseHelper
+  puts "DataMapper #{DataMapper::VERSION}, sqlite3"
+
+  def connection
+    DataMapper.repository.adapter
+  end
+
+  private
+
+  def default_config
+    db_config['sqlite3']
+  end
+
+  def create_db
+    # NO-OP
+  end
+
+  def establish_connection(config = default_config)
+    DataMapper.setup(:default, config)
+  end
+end
+

spec/support/data_mapper/sqlite3_setup.rb

@@ -1,36 +0,0 @@
-require 'support/active_record/database_setup'
-require 'support/data_mapper/schema_setup'
-
-class DataMapperSQLite3Helper
-  puts "DataMapper #{DataMapper::VERSION}, sqlite3"
-
-  def data_mapper_sqlite3_setup
-    create_db
-    establish_connection
-    data_mapper_load_schema
-  end
-
-  def data_mapper_sqlite3_connection
-    DataMapper.repository.adapter
-  end
-
-  def data_mapper_sqlite3_teardown
-    DataMapper.repository.adapter.truncate_tables(DataMapper::Model.descendants.map { |d| d.storage_names[:default] || d.name.underscore })
-  end
-
-  private
-
-  def default_config
-    db_config['sqlite3']
-  end
-
-  def create_db
-    @encoding = default_config['encoding'] || ENV['CHARSET'] || 'utf8'
-    establish_connection(default_config.merge('database' => 'sqlite3', 'schema_search_path' => 'public'))
-  end
-
-  def establish_connection(config = default_config)
-    DataMapper.setup(:default, config)
-  end
-end
-