Change ProjectFinder so starred can be combined with other filters

The `starred` parameter couldn't be used in combination with `trending` or
`non_public`. But this is changed now.

app/finders/projects_finder.rb

@@ -31,6 +31,7 @@ class ProjectsFinder < UnionFinder
     items = by_ids(items)
     items = union(items)
     items = by_personal(items)
+    items = by_starred(items)
     items = by_visibilty_level(items)
     items = by_tags(items)
     items = by_search(items)
@@ -45,8 +46,6 @@ class ProjectsFinder < UnionFinder
     if params[:trending].present?
       projects << Project.trending
-    elsif params[:starred].present? && current_user
-      projects << current_user.viewable_starred_projects
     else
       projects << current_user.authorized_projects if current_user
       projects << Project.unscoped.public_to_user(current_user) unless params[:non_public].present?
@@ -67,6 +66,10 @@ class ProjectsFinder < UnionFinder
     (params[:personal].present? && current_user) ? items.personal(current_user) : items
   end
+  def by_starred(items)
+    (params[:starred].present? && current_user) ? items.starred_by(current_user) : items
+  end
+
   def by_visibilty_level(items)
     params[:visibility_level].present? ? items.where(visibility_level: params[:visibility_level]) : items
   end

spec/finders/projects_finder_spec.rb

@@ -146,13 +146,19 @@ describe ProjectsFinder do
       it { is_expected.to eq([private_project]) }
     end
-    describe 'filter by viewable_starred_projects' do
+    describe 'filter by starred' do
       let(:params) { { starred: true } }
       before do
         current_user.toggle_star(public_project)
       end
       it { is_expected.to eq([public_project]) }
+
+      it 'returns only projects the user has access to' do
+        current_user.toggle_star(private_project)
+
+        is_expected.to eq([public_project])
+      end
     end
     describe 'sorting' do