Rspec issue when testing with have_subscribed_to_events

[remoteweb]

Rspec issue when testing with have_subscribed_to_events

[remoteweb]

Thanks for you quick reply and assignment.

Did you expect a subscription to exist without explicitly defining it?

The subscriber get initialised within the RailsEventStore initializer like this

 Rails.configuration.event_store.tap do |store|
        store.subscribe(OnHubCompanyUpdated::SyncCompany.new, to: [HubCompanyUpdated])

        store.subscribe_to_all_events(RailsEventStore::LinkByEventType.new)
        store.subscribe_to_all_events(RailsEventStore::LinkByCorrelationId.new)
        store.subscribe_to_all_events(RailsEventStore::LinkByCausationId.new)
end

I expect the subscriber to exist in my spec and I think it does exist as I have binding.pry inside the matcher and I get this

tes [3] pry(#<RubyEventStore::RSpec::HaveSubscribedToEvents>)>  event_store.subscribers_for(expected.first)

[#<OnHubCompanyUpdated::SyncCompany:0x00000001201f6e88>, ...]

The test is

expect(OnHubCompanyUpdated::SyncCompany).to have_subscribed_to_events(HubCompanyUpdated).in(event_store)

What do you mean by "definition is different than in docs"

If i initialize the subscriber without .new

Rails.configuration.event_store.tap do |store|
        store.subscribe(OnHubCompanyUpdated::SyncCompany, to: [HubCompanyUpdated])
end

the matcher works, and the expectation pass, but in RailsEventStore documentation, the instructions to add a subscriber is like this

event_store.subscribe(OrderNotifier.new, to: [OrderCancelled])

[pjurewicz]

Hey @remoteweb, thanks for posting!
I'm not sure if I get it. Did you expect a subscription to exist without explicitly defining it?
What do you mean by "definition is different than in docs"?

[pjurewicz]

Thanks, now I get it. Will review this assertion definition soon.

[pjurewicz]

Minimal code to reproduce your case:

  it 'got subscribed' do
    event_store.within do
      expect(SyncCompany).to have_subscribed_to_events(HubCompanyUpdated).in(event_store)
    end.subscribe(SyncCompany, to: [HubCompanyUpdated]).call
  end

⬆️ this test passes 🟢

  it 'got subscribed' do
   event_store.within do
     expect(SyncCompany).to have_subscribed_to_events(HubCompanyUpdated).in(event_store)
   end.subscribe(SyncCompany.new, to: [HubCompanyUpdated]).call
 end

⬆️ this one fails 🔴

It is tricky, but I do not consider this as an issue. In the second case, you pass a certain instance of SyncCompany class to subscribe method. To test this subscription properly, you should pass the same instance to the assertion.

  it 'got subscribed' do
    handler = SyncCompany.new
    event_store.within do
      expect(handler).to have_subscribed_to_events(HubCompanyUpdated).in(event_store)
    end.subscribe(handler, to: [HubCompanyUpdated]).call
  end

⬆️ this test passes 🟢

If you don't care about a stateful handler, you should rather pass a class to the subscribe method.
The difference between those two is described in this section of the documentation.

Perhaps the documentation should focus more on stateless subscription handlers, as they are the norm. Thank you for pointing it out.

[remoteweb]

🙏 Thanks for the time put in to add this great explanation. I was falsely expecting the spec helpers to handle all cases by default and I missed to understand properly all different handler configurations.