Reduce N+1 from Activity Dashboard and Banzai

There is a combination of few strategies implemented here:

1. Few relations were eager loaded
2. Changed few polymorphic routes to specific ones so we don't have to
   use `#becomes(Namespace)` which doesn't preserve association cache

4 files changed, 7 insertions, 3 deletions

diff --git a/app/helpers/events_helper.rb b/app/helpers/events_helper.rb
index 3ce2398f1de..1371e9993b4 100644
--- a/app/helpers/events_helper.rb
+++ b/app/helpers/events_helper.rb
@@ -161,6 +161,10 @@ module EventsHelper
       project_commit_url(event.project, event.note_target, anchor: dom_id(event.target))
     elsif event.project_snippet_note?
       project_snippet_url(event.project, event.note_target, anchor: dom_id(event.target))
+    elsif event.issue_note?
+      project_issue_url(event.project, id: event.note_target, anchor: dom_id(event.target))
+    elsif event.merge_request_note?
+      project_merge_request_url(event.project, id: event.note_target, anchor: dom_id(event.target))
     else
       polymorphic_url([event.project.namespace.becomes(Namespace),
                        event.project, event.note_target],
diff --git a/app/helpers/projects_helper.rb b/app/helpers/projects_helper.rb
index 87aebe415c8..7c8557a1a8a 100644
--- a/app/helpers/projects_helper.rb
+++ b/app/helpers/projects_helper.rb
@@ -2,7 +2,7 @@
 
 module ProjectsHelper
   def link_to_project(project)
-    link_to [project.namespace.becomes(Namespace), project], title: h(project.name) do
+    link_to namespace_project_path(namespace_id: project.namespace, id: project), title: h(project.name) do
       title = content_tag(:span, project.name, class: 'project-name')
 
       if project.namespace
diff --git a/app/models/event.rb b/app/models/event.rb
index 2e690f8c013..2ceef412af5 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -87,7 +87,7 @@ class Event < ActiveRecord::Base
   scope :with_associations, -> do
     # We're using preload for "push_event_payload" as otherwise the association
     # is not always available (depending on the query being built).
-    includes(:author, :project, project: :namespace)
+    includes(:author, :project, project: [:project_feature, :import_data, :namespace])
       .preload(:target, :push_event_payload)
   end
 
diff --git a/app/models/note.rb b/app/models/note.rb
index a6ae4f58ac4..17c7d97fa0a 100644
--- a/app/models/note.rb
+++ b/app/models/note.rb
@@ -131,7 +131,7 @@ class Note < ActiveRecord::Base
   scope :with_associations, -> do
     # FYI noteable cannot be loaded for LegacyDiffNote for commits
     includes(:author, :noteable, :updated_by,
-             project: [:project_members, { group: [:group_members] }])
+             project: [:project_members, :namespace, { group: [:group_members] }])
   end
   scope :with_metadata, -> { includes(:system_note_metadata) }