Eager load event target authors whenever possibleconditionally-eager-load-event-target-authors

This ensures that the "author" association of an event's "target"
association is eager loaded whenever the "target" association defines an
"author" association. This in turn solves the N+1 query problem we first
tried to solve in
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15788 but caused
problems when displaying milestones as those don't define an "author"
association.

The approach in this commit does mean that the authors are _always_
eager loaded since this takes place in the "belongs_to" block. This
however shouldn't pose too much of a problem, and as far as I can tell
there's no real way around this unfortunately.

1 files changed, 7 insertions, 0 deletions

diff --git a/spec/features/dashboard/activity_spec.rb b/spec/features/dashboard/activity_spec.rb
index bd115785646..a74a8aac2b2 100644
--- a/spec/features/dashboard/activity_spec.rb
+++ b/spec/features/dashboard/activity_spec.rb
@@ -24,6 +24,7 @@ feature 'Dashboard > Activity' do
     end
 
     let(:note) { create(:note, project: project, noteable: merge_request) }
+    let(:milestone) { create(:milestone, :active, project: project, title: '1.0') }
 
     let!(:push_event) do
       event = create(:push_event, project: project, author: user)
@@ -54,6 +55,10 @@ feature 'Dashboard > Activity' do
       create(:event, :commented, project: project, target: note, author: user)
     end
 
+    let!(:milestone_event) do
+      create(:event, :closed, project: project, target: milestone, author: user)
+    end
+
     before do
       project.add_master(user)
 
@@ -68,6 +73,7 @@ feature 'Dashboard > Activity' do
         expect(page).to have_content('accepted')
         expect(page).to have_content('closed')
         expect(page).to have_content('commented on')
+        expect(page).to have_content('closed milestone')
       end
     end
 
@@ -107,6 +113,7 @@ feature 'Dashboard > Activity' do
         expect(page).not_to have_content('accepted')
         expect(page).to have_content('closed')
         expect(page).not_to have_content('commented on')
+        expect(page).to have_content('closed milestone')
       end
     end