Using DataBase Cleaner gem with DataMapper

Question

I am writing a test using RSpec and FactoryGirl. In my models DataMappers have been used. Here in RSpec I am testing two methods update and index function of my controller where I am using two objects A, B and C. I have created them by using FactoryGirl as follows:

before(:each) do
  @A = FactoryGirl.create(:A)
  @B = FactoryGirl.create(:B)
  @C = FactoryGirl.create(:C)
end

Now I want to clean them after each test with DataBase Cleaner Gem. I have searched it in Google but most of the articles talk about how to use DataBase cleaner Gem with ActiveRecord but none of them clearly specify how to use DataBaseCleaner gem with DataMapper. So if anyone gives me small example of RSpec file with DataBase cleaner where DataMapper have been used, I will be really grateful. Thanks in advance.

Answer 1

First make sure you have dm-transactions in your Gemfile as well as database_cleaner and require both in your spec helper:

require 'dm-transactions'
require 'database_cleaner'

Then you just need to configure DatabaseCleaner to use DataMapper with the following line in your spec helper:

DatabaseCleaner[:data_mapper].strategy = :transaction

You can now use something similar to this in your specs to let DatabaseCleaner know when the transactions start and when to clean:

before :each do
  DatabaseCleaner.start
end

after :each do
  DatabaseCleaner.clean
end

More details on DatabaseCleaner readme: https://github.com/bmabey/database_cleaner