Keep your specs from needlessly hitting the database

thing_spec.rb

describe ThingsController do
  describe '#create' do
    let(:thing_data) { { name: 'Name' } }
    it 'creates a new Thing and hits the DB 3x' do
      expect { post :create, thing: thing_data }.to change { Thing.count }.by 1
      # other response-related expectations here      
    end

    it 'creates a new Thing and hits the DB once' do
      post :create, thing: thing_data

      assigns(:thing).should be_persisted
      # other response-related expectations here
    end
  end
end