Fix some n+1 queries on front page

Gemfile

@@ -43,6 +43,7 @@ group :development do
   gem 'guard-rspec'
   gem 'rb-fsevent'
   gem 'terminal-notifier-guard'
+  gem "bullet"
 end
 
 group :test, :development do

Gemfile.lock

@@ -43,6 +43,8 @@ GEM
       railties (>= 3.1.0)
       sass-rails (>= 3.1.0)
     builder (3.0.4)
+    bullet (4.6.0)
+      uniform_notifier
     capybara (2.1.0)
       mime-types (>= 1.16)
       nokogiri (>= 1.3.3)
@@ -278,6 +280,7 @@ GEM
     uglifier (1.3.0)
       execjs (>= 0.3.0)
       multi_json (~> 1.0, >= 1.0.2)
+    uniform_notifier (1.2.0)
     uuidtools (2.1.4)
     warden (1.2.1)
       rack (>= 1.0)
@@ -296,6 +299,7 @@ DEPENDENCIES
   awesome_print
   backbone-on-rails
   bootstrap-sass-rails
+  bullet
   capybara (>= 2.0.1)
   capybara-screenshot
   coffee-rails

app/controllers/events_controller.rb

@@ -5,8 +5,8 @@ class EventsController < ApplicationController
   before_filter :set_time_zone, only: [:create, :update]
 
   def index
-    @events = Event.upcoming
-    @past_events = Event.past
+    @events = Event.upcoming.includes(:event_sessions, :location)
+    @past_events = Event.past.includes(:location)
   end
 
   def show

app/helpers/events_helper.rb

@@ -23,6 +23,10 @@ def organizer_list
     @event.organizers_with_legacy.empty? ? [] : @event.organizers_with_legacy
   end
 
+  def formatted_event_date(event)
+    l event.date_in_time_zone(:starts_at), :format => :date_as_day_mdy
+  end
+
   def formatted_session_date(event_session)
     l event_session.date_in_time_zone(:starts_at), :format => :date_as_day_mdy
   end

app/models/event.rb

@@ -123,6 +123,10 @@ def self.past
     where('ends_at < ?', Time.now.utc)
   end
 
+  def date_in_time_zone start_or_end
+    read_attribute(start_or_end).in_time_zone(ActiveSupport::TimeZone.new(time_zone))
+  end
+
   def upcoming?
     ends_at > Time.now
   end

app/models/event_session.rb

@@ -3,7 +3,7 @@ class EventSession < ActiveRecord::Base
   validates_presence_of :starts_at, :ends_at, :name
   validates_uniqueness_of :name, scope: [:event_id]
 
-  belongs_to :event
+  belongs_to :event, inverse_of: :event_sessions
   has_many :rsvp_sessions, dependent: :destroy
   has_many :rsvps, :through => :rsvp_sessions
 

app/views/events/_event.html.erb

@@ -13,6 +13,6 @@
       <%= formatted_session_date_and_time(session) %><% if index < event.event_sessions.length - 1 %><br /><% end %>
     <% end %>
   <% else %>
-    <%= formatted_session_date(event.event_sessions.last) %>
+    <%= formatted_event_date(event) %>
   <% end %>
 </td>

config/environments/development.rb

@@ -37,4 +37,9 @@
 
   # Fake, boring secret token for dev
   config.secret_token = ('x' * 30)
+
+  config.after_initialize do
+    Bullet.enable = ENV['BULLET_ENABLE']
+    Bullet.bullet_logger = true
+  end
 end