Optimize maximum user access level lookup in loading of notes

NotesHelper#note_editable? and ProjectTeam#human_max_access currently
take about 16% of the load time of an issue page. This MR preloads
the maximum access level of users for all notes in issues and merge
requests with several queries instead of one per user and caches
the result in RequestStore.

1 files changed, 56 insertions, 0 deletions

diff --git a/spec/models/ability_spec.rb b/spec/models/ability_spec.rb
index 1acb5846fcf..cd5f40fe3d2 100644
--- a/spec/models/ability_spec.rb
+++ b/spec/models/ability_spec.rb
@@ -1,6 +1,62 @@
 require 'spec_helper'
 
 describe Ability, lib: true do
+  describe '.can_edit_note?' do
+    let(:project) { create(:empty_project) }
+    let!(:note) { create(:note_on_issue, project: project) }
+
+    context 'using an anonymous user' do
+      it 'returns false' do
+        expect(described_class.can_edit_note?(nil, note)).to be_falsy
+      end
+    end
+
+    context 'using a system note' do
+      it 'returns false' do
+        system_note = create(:note, system: true)
+        user = create(:user)
+
+        expect(described_class.can_edit_note?(user, system_note)).to be_falsy
+      end
+    end
+
+    context 'using users with different access levels' do
+      let(:user) { create(:user) }
+
+      it 'returns true for the author' do
+        expect(described_class.can_edit_note?(note.author, note)).to be_truthy
+      end
+
+      it 'returns false for a guest user' do
+        project.team << [user, :guest]
+
+        expect(described_class.can_edit_note?(user, note)).to be_falsy
+      end
+
+      it 'returns false for a developer' do
+        project.team << [user, :developer]
+
+        expect(described_class.can_edit_note?(user, note)).to be_falsy
+      end
+
+      it 'returns true for a master' do
+        project.team << [user, :master]
+
+        expect(described_class.can_edit_note?(user, note)).to be_truthy
+      end
+
+      it 'returns true for a group owner' do
+        group = create(:group)
+        project.project_group_links.create(
+          group: group,
+          group_access: Gitlab::Access::MASTER)
+        group.add_owner(user)
+
+        expect(described_class.can_edit_note?(user, note)).to be_truthy
+      end
+    end
+  end
+
   describe '.users_that_can_read_project' do
     context 'using a public project' do
       it 'returns all the users' do