Merge branch '300150-cache-search-tab-counters' into 'master'

Cache /search/count requests in the browser

See merge request gitlab-org/gitlab!55036

app/controllers/search_controller.rb

@@ -49,6 +49,12 @@ class SearchController < ApplicationController
     scope = search_service.scope
     count = search_service.search_results.formatted_count(scope)
 
+    # Users switching tabs will keep fetching the same tab counts so it's a
+    # good idea to cache in their browser just for a short time. They can still
+    # clear cache if they are seeing an incorrect count but inaccurate count is
+    # not such a bad thing.
+    expires_in 1.minute
+
     render json: { count: count }
   end
 

changelogs/unreleased/300150-cache-search-tab-counters.yml

+---
+title: Cache /search/count requests in the browser
+merge_request: 55036
+author:
+type: performance

spec/controllers/search_controller_spec.rb

@@ -252,6 +252,14 @@ RSpec.describe SearchController do
           get :count, params: { search: 'hello' }
         end.to raise_error(ActionController::ParameterMissing)
       end
+
+      it 'sets private cache control headers' do
+        get :count, params: { search: 'hello', scope: 'projects' }
+
+        expect(response).to have_gitlab_http_status(:ok)
+
+        expect(response.headers['Cache-Control']).to include('max-age=60, private')
+      end
     end
 
     describe 'GET #autocomplete' do