Do I need to create each object in this test?

Question

My test looks like this:

def setup
    @period_registration= FactoryGirl.create(:period_registration)
  end


 test "should post save_period" do
    sign_in(FactoryGirl.create(:user))
     assert_difference('PeriodRegistration.count') do
      post :save_period, period_registration: FactoryGirl.attributes_for(:period_registration)
    end
    assert_not_nil assigns(:period_registration)

  end

But when I run it, I get this error:

 1) Error:
test_should_post_save_period(PeriodRegistrationsControllerTest):
NoMethodError: undefined method `event' for nil:NilClass

Here is my controller:

  def save_period
    @period_registration = PeriodRegistration.new(params[:registration])
    @period_registration.save
    flash[:success] = "Successfully Registered for Session."
    redirect_to event_url(@period_registration.period.event)
  end

My factories look like this:

factory :event do
    name 'First Event'
    street '123 street'
    city 'Chicago'
    state 'Iowa'
    date Date.today
  end


  factory :period do
    name 'First Period'
    description 'This is a description'
    start_time Time.now + 10.days
    end_time Time.now + 10.days + 2.hours
    event
    product
  end

factory :period_registration do
    user
    period
  end

Do I need to create a period object and an event object? If so how? I don't think this is the issue because, I believe by having "period" and then "product" and then "event" in the various factories automatically creates these.

Any ideas on where to look from here?

Answer 1

The short answer - yes, you do create objects.

The long answer:

1. In controller:

   @period_registration.period.event
   

   This line of code violate The Law Of Demeter. This is not good design. This line of code should looks like:

   @period_registration.event
   

   But you must create new method in PeriodRegistration model. The simplest variant of method can be:

   def event
     period.event
   end
   

2. In controller: You does not check if PeriodRegistration model saved or not.

3. As I understand PeriodRegistration model have 2 associations and when you use FactoryGirl.attributes_for, the factory does not create associated objects, it just give you set of attributes for PeriodRegistration. To make this test pass you should create these 2 objects befor you call controller. Aslo the best practice is - test should have only one assertion. For example:

   def setup
     @user = FactoryGirl.create(:user)
     @period = FactoryGirl.create(:period)
   end
   
   test "should post save_period" do
     sign_in(@user)
     assert_difference('PeriodRegistration.count') do
       post :save_period, period_registration: FactoryGirl.attributes_for(:period_registration, user: @user, period: @period)
     end
   end
   
   test "should assings @period_registration" do
     sign_in(@user)
     post :save_period, period_registration: FactoryGirl.attributes_for(:period_registration, user: @user, period: @period)
     assert_not_nil assigns(:period_registration)
   end
   

4. When testing controller you can use mock object instead of real model.