Optimize /api/v4/projects endpoint for visibility level

Previously when a user requested a list of projects,
`Project#public_or_visible_to_user` would search all authorized projects
and public/internal projects as well. However, when a user requests a
specific `visibility_level` (e.g. private), that should reduce the
search space, and we shouldn't need to load public/internal projects.

Improves https://gitlab.com/gitlab-org/gitlab-ce/issues/59329

1 files changed, 48 insertions, 1 deletions

diff --git a/spec/models/project_spec.rb b/spec/models/project_spec.rb
index fc9d9a28b9a..90dcf861849 100644
--- a/spec/models/project_spec.rb
+++ b/spec/models/project_spec.rb
@@ -2710,7 +2710,7 @@ describe Project do
   end
 
   describe '#any_lfs_file_locks?', :request_store do
-    set(:project) { create(:project) }
+    let!(:project) { create(:project) }
 
     it 'returns false when there are no LFS file locks' do
       expect(project.any_lfs_file_locks?).to be_falsey
@@ -3148,6 +3148,53 @@ describe Project do
         expect(projects).to eq([public_project])
       end
     end
+
+    context 'with requested visibility levels' do
+      set(:internal_project) { create(:project, :internal, :repository) }
+      set(:private_project_2) { create(:project, :private) }
+
+      context 'with admin user' do
+        set(:admin) { create(:admin) }
+
+        it 'returns all projects' do
+          projects = described_class.all.public_or_visible_to_user(admin, [])
+
+          expect(projects).to match_array([public_project, private_project, private_project_2, internal_project])
+        end
+
+        it 'returns all public and private projects' do
+          projects = described_class.all.public_or_visible_to_user(admin, [Gitlab::VisibilityLevel::PUBLIC, Gitlab::VisibilityLevel::PRIVATE])
+
+          expect(projects).to match_array([public_project, private_project, private_project_2])
+        end
+
+        it 'returns all private projects' do
+          projects = described_class.all.public_or_visible_to_user(admin, [Gitlab::VisibilityLevel::PRIVATE])
+
+          expect(projects).to match_array([private_project, private_project_2])
+        end
+      end
+
+      context 'with regular user' do
+        it 'returns authorized projects' do
+          projects = described_class.all.public_or_visible_to_user(user, [])
+
+          expect(projects).to match_array([public_project, private_project, internal_project])
+        end
+
+        it "returns user's public and private projects" do
+          projects = described_class.all.public_or_visible_to_user(user, [Gitlab::VisibilityLevel::PUBLIC, Gitlab::VisibilityLevel::PRIVATE])
+
+          expect(projects).to match_array([public_project, private_project])
+        end
+
+        it 'returns one private project' do
+          projects = described_class.all.public_or_visible_to_user(user, [Gitlab::VisibilityLevel::PRIVATE])
+
+          expect(projects).to eq([private_project])
+        end
+      end
+    end
   end
 
   describe '.with_feature_available_for_user' do