Check for feature status in SnippetsFinder

So that execution is halted when finding
project snippets for a project that is
disabled

app/finders/snippets_finder.rb

@@ -61,9 +61,11 @@ class SnippetsFinder < UnionFinder
   def execute
     # The snippet query can be expensive, therefore if the
     # author or project params have been passed and they don't
-    # exist, it's better to return
+    # exist, or if a Project has been passed and has snippets
+    # disabled, it's better to return
     return Snippet.none if author.nil? && params[:author].present?
     return Snippet.none if project.nil? && params[:project].present?
+    return Snippet.none if project && !project.feature_available?(:snippets, current_user)
 
     items = init_collection
     items = by_ids(items)

changelogs/unreleased/vh-snippets-finder-tweak.yml

+---
+title: Improve SnippetsFinder performance with disabled project snippets
+merge_request: 26295
+author:
+type: performance

spec/finders/snippets_finder_spec.rb

@@ -284,6 +284,17 @@ describe SnippetsFinder do
         expect(described_class.new(user).execute).to contain_exactly(private_personal_snippet, internal_personal_snippet, public_personal_snippet)
       end
     end
+
+    context 'when project snippets are disabled' do
+      it 'returns quickly' do
+        disabled_snippets_project = create(:project, :snippets_disabled)
+        finder = described_class.new(user, project: disabled_snippets_project.id)
+
+        expect(finder).not_to receive(:init_collection)
+        expect(Snippet).to receive(:none).and_call_original
+        expect(finder.execute).to be_empty
+      end
+    end
   end
 
   it_behaves_like 'snippet visibility'