Only update the sidebar count caches when needed

This ensures the issues/MR cache of the sidebar is only updated when the
state or confidential flags changes, instead of changing this for every
update.

app/models/issue.rb

@@ -269,7 +269,13 @@ class Issue < ActiveRecord::Base
     end
   end
+  def update_project_counter_caches?
+    state_changed? || confidential_changed?
+  end
+
   def update_project_counter_caches
+    return unless update_project_counter_caches?
+
     Projects::OpenIssuesCountService.new(project).refresh_cache
   end

app/models/merge_request.rb

@@ -942,7 +942,13 @@ class MergeRequest < ActiveRecord::Base
     true
   end
+  def update_project_counter_caches?
+    state_changed?
+  end
+
   def update_project_counter_caches
+    return unless update_project_counter_caches?
+
     Projects::OpenMergeRequestsCountService.new(target_project).refresh_cache
   end

changelogs/unreleased/sidebar-cache-updates.yml

+---
+title: Only update the sidebar count caches when needed
+merge_request:
+author:
+type: other

spec/models/issue_spec.rb

@@ -769,4 +769,22 @@ describe Issue do
       expect(described_class.public_only).to eq([public_issue])
     end
   end
+
+  describe '#update_project_counter_caches?' do
+    it 'returns true when the state changes' do
+      subject.state = 'closed'
+
+      expect(subject.update_project_counter_caches?).to eq(true)
+    end
+
+    it 'returns true when the confidential flag changes' do
+      subject.confidential = true
+
+      expect(subject.update_project_counter_caches?).to eq(true)
+    end
+
+    it 'returns false when the state or confidential flag did not change' do
+      expect(subject.update_project_counter_caches?).to eq(false)
+    end
+  end
 end

spec/models/merge_request_spec.rb

@@ -1700,4 +1700,16 @@ describe MergeRequest do
         .to change { project.open_merge_requests_count }.from(1).to(0)
     end
   end
+
+  describe '#update_project_counter_caches?' do
+    it 'returns true when the state changes' do
+      subject.state = 'closed'
+
+      expect(subject.update_project_counter_caches?).to eq(true)
+    end
+
+    it 'returns false when the state did not change' do
+      expect(subject.update_project_counter_caches?).to eq(false)
+    end
+  end
 end