Implement strict loading association (#189)

Avoid N+1 query

app/controllers/admin/events_controller.rb

@@ -5,8 +5,7 @@ class EventsController < AdminController
     before_action :set_event, only: %w[edit update destroy]
 
     def index
-      @events = Event.includes(:speakers)
-                     .order(date: :desc)
+      @events = Event.includes(:speakers).order(date: :desc)
     end
 
     def new
@@ -54,11 +53,18 @@ def authorize_event
     end
 
     def set_event
-      @event = Event.find_by(id: params[:id])
+      @event = Event.includes(:talks).find_by(id: params[:id])
     end
 
     def event_params
-      params.require(:event).permit(:title, :location, :description, :date, :type, :panel_video_link)
+      params.require(:event).permit(
+        :title,
+        :location,
+        :description,
+        :date,
+        :type,
+        :panel_video_link,
+      )
     end
   end
 end

app/controllers/api/events_controller.rb

@@ -3,7 +3,8 @@
 module Api
   class EventsController < ApplicationController
     def past
-      events = Event.where('date < ?', DateTime.current).order(date: :desc)
+      events =
+        Event.includes(:talks, :speakers).where('date < ?', DateTime.current).order(date: :desc)
       events_by_date =
         events
           .group_by { |event| event.date.year }
@@ -16,7 +17,7 @@ def past
 
     def past_by_month_day
       event_date = DateTime.new(params[:year].to_i, params[:month].to_i, params[:day].to_i)
-      event = Event.where(date: event_date..event_date.end_of_day).first
+      event = Event.includes(:talks, :speakers).where(date: event_date..event_date.end_of_day).first
       if event.present?
         render status: 200, json: { data: event.as_json(include: %i[talks speakers]) }
       else
@@ -25,7 +26,8 @@ def past_by_month_day
     end
 
     def upcoming
-      events = Event.where('date > ?', DateTime.current).order(date: :asc)
+      events =
+        Event.includes(:talks, :speakers).where('date > ?', DateTime.current).order(date: :asc)
       events_by_date =
         events
           .group_by { |event| event.date.year }

config/environments/development.rb

@@ -72,4 +72,8 @@
 
   # Uncomment if you wish to allow Action Cable access from any origin.
   # config.action_cable.disable_request_forgery_protection = true
+
+  # Sets the returned relation to strict_loading mode.
+  # This will raise an error if the record tries to lazily load an association.
+  config.active_record.strict_loading_by_default = true
 end

config/environments/production.rb

@@ -92,4 +92,8 @@
 
   # Do not dump schema after migrations.
   config.active_record.dump_schema_after_migration = false
+
+  # Sets the returned relation to strict_loading mode.
+  # This will raise an error if the record tries to lazily load an association.
+  config.active_record.strict_loading_by_default = :log
 end

config/environments/test.rb

@@ -58,4 +58,8 @@
 
   # Annotate rendered view with file names.
   # config.action_view.annotate_rendered_view_with_filenames = true
+
+  # Sets the returned relation to strict_loading mode.
+  # This will raise an error if the record tries to lazily load an association.
+  config.active_record.strict_loading_by_default = true
 end

spec/controllers/admin/events_controller_spec.rb

@@ -105,6 +105,7 @@
   describe 'GET #new' do
     it 'assigns a new event to @event' do
       get :new
+
       expect(response).to have_http_status(302)
     end
   end
@@ -113,6 +114,7 @@
     context 'when user is not authenticated' do
       it 'returns 302' do
         post :create
+
         expect(response).to have_http_status(302)
         expect(response).to redirect_to(new_user_session_path)
       end
@@ -124,6 +126,7 @@
 
       it 'returns 401' do
         post :create
+
         expect(response).to have_http_status(401)
       end
     end
@@ -157,12 +160,14 @@
 
       it 'redirects to index page when event exists' do
         delete :destroy, params: { id: event.id }
+
         expect(response).to redirect_to(admin_events_path)
         expect(Event.exists?(event.id)).to be(false)
       end
 
       it 'returns 404 when the event does not exist' do
         delete :destroy, params: { id: 'fakefake' }
+
         expect(response).to have_http_status(404)
       end
     end
@@ -185,6 +190,7 @@
 
       it 'redirects to login' do
         delete :destroy, params: { id: event.id }
+
         expect(response).to redirect_to(new_user_session_path)
         expect(Event.exists?(event.id)).to be(true)
       end