Add Event show action to the API

Implements getlago/lago#48

app/controllers/api/v1/events_controller.rb

@@ -17,6 +17,22 @@ def create
         head(:ok)
       end
 
+      def show
+        event = Event.find_by(
+          organization: current_organization,
+          transaction_id: params[:id]
+        )
+
+        return head(:not_found) unless event
+
+        render(
+          json: ::V1::EventSerializer.new(
+            event,
+            root_name: 'event',
+          )
+        )
+      end
+
       private
 
       def create_params

app/serializers/v1/event_serializer.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+#
+module V1
+  class EventSerializer < ModelSerializer
+    def serialize
+      {
+        lago_id: model.id,
+        transaction_id: model.transaction_id,
+        customer_id: model.customer_id,
+        code: model.code,
+        timestamp: model.timestamp.iso8601,
+        properties: model.properties,
+        created_at: model.created_at.iso8601
+      }
+    end
+  end
+end

config/routes.rb

@@ -21,7 +21,7 @@
       resources :subscriptions, only: %i[create]
       delete '/subscriptions', to: 'subscriptions#terminate', as: :terminate
 
-      resources :events, only: %i[create]
+      resources :events, only: %i[create show]
       resources :applied_coupons, only: %i[create]
       resources :applied_add_ons, only: %i[create]
 

spec/factories/event_factory.rb

@@ -7,5 +7,6 @@
 
     transaction_id { SecureRandom.uuid }
     code { Faker::Name.name.underscore }
+    timestamp { Time.current }
   end
 end

spec/requests/api/v1/events_spec.rb

@@ -39,4 +39,34 @@
       end
     end
   end
+
+  describe 'GET /events/:id' do
+    let(:event) { create(:event) }
+
+    it 'returns an event' do
+      get_with_token(
+        event.organization,
+        '/api/v1/events/' + event.transaction_id
+      )
+
+      expect(response).to have_http_status(:ok)
+
+      api_event = JSON.parse(response.body)['event']
+
+      %w[code transaction_id customer_id].each do |property|
+        expect(api_event[property]).to eq event.attributes[property]
+      end
+    end
+
+    context 'with a non-existing transaction_id' do
+      it 'returns not found' do
+        get_with_token(
+          organization,
+          '/api/v1/events/' + SecureRandom.uuid
+        )
+
+        expect(response).to have_http_status(:not_found)
+      end
+    end
+  end
 end