Use Atom update times of the first event

app/models/event.rb

@@ -49,7 +49,7 @@ class Event < ActiveRecord::Base
   scope :code_push, -> { where(action: PUSHED) }
 
   scope :in_projects, ->(projects) do
-    where(project_id: projects.reorder(nil).id_only).recent
+    where(project_id: projects.select(:id).reorder(nil)).recent
   end
 
   scope :with_associations, -> { includes(project: :namespace) }
@@ -68,12 +68,6 @@ class Event < ActiveRecord::Base
             [Event::CREATED, Event::CLOSED, Event::MERGED])
     end
 
-    def latest_update_time
-      row = select(:updated_at, :project_id).reorder(id: :desc).take
-
-      row ? row.updated_at : nil
-    end
-
     def limit_recent(limit = 20, offset = nil)
       recent.limit(limit).offset(offset)
     end

app/models/project.rb

@@ -215,8 +215,6 @@ class Project < ActiveRecord::Base
   scope :public_and_internal_only, -> { where(visibility_level: Project.public_and_internal_levels) }
   scope :non_archived, -> { where(archived: false) }
 
-  scope :id_only, -> { select(:id) }
-
   state_machine :import_status, initial: :none do
     event :import_start do
       transition [:none, :finished] => :started

app/views/dashboard/projects/index.atom.builder

@@ -4,7 +4,7 @@ xml.feed "xmlns" => "http://www.w3.org/2005/Atom", "xmlns:media" => "http://sear
   xml.link    href: dashboard_projects_url(format: :atom, private_token: current_user.try(:private_token)), rel: "self", type: "application/atom+xml"
   xml.link    href: dashboard_projects_url, rel: "alternate", type: "text/html"
   xml.id      dashboard_projects_url
-  xml.updated @events.latest_update_time.xmlschema if @events.any?
+  xml.updated @events[0].updated_at.xmlschema if @events[0]
 
   @events.each do |event|
     event_to_atom(xml, event)

app/views/groups/show.atom.builder

@@ -4,7 +4,7 @@ xml.feed "xmlns" => "http://www.w3.org/2005/Atom", "xmlns:media" => "http://sear
   xml.link    href: group_url(@group, format: :atom, private_token: current_user.try(:private_token)), rel: "self", type: "application/atom+xml"
   xml.link    href: group_url(@group), rel: "alternate", type: "text/html"
   xml.id      group_url(@group)
-  xml.updated @events.latest_update_time.xmlschema if @events.any?
+  xml.updated @events[0].updated_at.xmlschema if @events[0]
 
   @events.each do |event|
     event_to_atom(xml, event)

app/views/projects/show.atom.builder

@@ -4,7 +4,7 @@ xml.feed "xmlns" => "http://www.w3.org/2005/Atom", "xmlns:media" => "http://sear
   xml.link    href: namespace_project_url(@project.namespace, @project, format: :atom, private_token: current_user.try(:private_token)), rel: "self", type: "application/atom+xml"
   xml.link    href: namespace_project_url(@project.namespace, @project), rel: "alternate", type: "text/html"
   xml.id      namespace_project_url(@project.namespace, @project)
-  xml.updated @events.latest_update_time.xmlschema if @events.any?
+  xml.updated @events[0].updated_at.xmlschema if @events[0?
 
   @events.each do |event|
     event_to_atom(xml, event)

app/views/users/show.atom.builder

@@ -4,7 +4,7 @@ xml.feed "xmlns" => "http://www.w3.org/2005/Atom", "xmlns:media" => "http://sear
   xml.link    href: user_url(@user, :atom), rel: "self", type: "application/atom+xml"
   xml.link    href: user_url(@user), rel: "alternate", type: "text/html"
   xml.id      user_url(@user)
-  xml.updated @events.latest_update_time.xmlschema if @events.any?
+  xml.updated @events[0].updated_at.xmlschema if @events[0]
 
   @events.each do |event|
     event_to_atom(xml, event)

spec/models/event_spec.rb

@@ -65,27 +65,6 @@ describe Event, models: true do
     it { expect(@event.author).to eq(@user) }
   end
 
-  describe '.latest_update_time' do
-    describe 'when events are present' do
-      let(:time) { Time.utc(2015, 1, 1) }
-
-      before do
-        create(:closed_issue_event, updated_at: time)
-        create(:closed_issue_event, updated_at: time + 5)
-      end
-
-      it 'returns the latest update time' do
-        expect(Event.latest_update_time).to eq(time + 5)
-      end
-    end
-
-    describe 'when no events exist' do
-      it 'returns nil' do
-        expect(Event.latest_update_time).to be_nil
-      end
-    end
-  end
-
   describe '.limit_recent' do
     let!(:event1) { create(:closed_issue_event) }
     let!(:event2) { create(:closed_issue_event) }