Merge branch '209912-memoize-sprites-icon-path' into 'master'

Avoid N+1 calls for image_path when rendering commits

See merge request gitlab-org/gitlab!36724

app/helpers/icons_helper.rb

@@ -28,10 +28,12 @@ module IconsHelper
   end
 
   def sprite_icon_path
-    # SVG Sprites currently don't work across domains, so in the case of a CDN
-    # we have to set the current path deliberately to prevent addition of asset_host
-    sprite_base_url = Gitlab.config.gitlab.url if ActionController::Base.asset_host
-    ActionController::Base.helpers.image_path('icons.svg', host: sprite_base_url)
+    @sprite_icon_path ||= begin
+      # SVG Sprites currently don't work across domains, so in the case of a CDN
+      # we have to set the current path deliberately to prevent addition of asset_host
+      sprite_base_url = Gitlab.config.gitlab.url if ActionController::Base.asset_host
+      ActionController::Base.helpers.image_path('icons.svg', host: sprite_base_url)
+    end
   end
 
   def sprite_file_icons_path

changelogs/unreleased/209912-memoize-sprites-icon-path.yml

+---
+title: Avoid N+1 calls for image_path when rendering commits
+merge_request: 36724
+author:
+type: performance

spec/helpers/icons_helper_spec.rb

@@ -22,8 +22,13 @@ RSpec.describe IconsHelper do
 
   describe 'sprite_icon_path' do
     it 'returns relative path' do
-      expect(sprite_icon_path)
-        .to eq icons_path
+      expect(sprite_icon_path).to eq(icons_path)
+    end
+
+    it 'only calls image_path once when called multiple times' do
+      expect(ActionController::Base.helpers).to receive(:image_path).once.and_call_original
+
+      2.times { sprite_icon_path }
     end
 
     context 'when an asset_host is set in the config it will return an absolute local URL' do