运行测试时，rspec是否访问数据库？

Question

I'm using rspec-rails to test a controller in my rails application. In one instance, I'm creating new objects to test that they're properly assigned to instance variables.

describe MainController do
    describe "GET #index" do
        it "properly assigns a colored ball" do
            ball1 = Ball.create(color: 'red')
            get :index
            expect(assigns(:red_balls)).to eq([ball1])
        end
    end
end

When I run the test, does rspec access the database to create ball1 and then delete it once the test is run?

Answer 1

From the snippet in your question, Yes Rspec access the DB configured as test in the database.yml file, if you want to clean out the DB/Records created by Rspec you can use the database_cleaner gem you can configure it as you deem fit.

eg:

add gem database_cleaner to your Gemfile

and the below to your spec_helper.rb file as specified by the database_cleaner documentation:

RSpec.configure do |config|

  config.before(:suite) do
    DatabaseCleaner.strategy = :transaction
    DatabaseCleaner.clean_with(:truncation)
  end

  config.before(:each) do
    DatabaseCleaner.start
  end

  config.after(:each) do
    DatabaseCleaner.clean
  end

end

Then database_cleaner would truncate the tables in the test db and leave them in a pristine state

Answer 2

To add to what bjhaid said above - Rspec should only be accessing you 'test' database. Check out the config/database.yml to see the configuration of your different databases.

So you do not have to worry about things in your development or production databases interfering with your testing database.

Answer 3

Yes, RSpec allows your database calls to go through, but with the rspec-rails gem under the default configuration, it will execute each test within a database transaction and will roll back that transaction at the end of each example with no action required on your part. No additional gem is required. See https://relishapp.com/rspec/rspec-rails/docs/transactions .