Allow filtering labels by a single character

When we use Gitlab::SQL::Pattern, this typically relates to a trigram
index. As the 'tri' indicates, we need at least three characters to be
able to use that index.

Labels don't have a trigram index, because we never allow you to search
for them globally: it's always in the context of a project or a
group. In that context, it's just as fast to search for a single
character (in general) because there is already a pretty specific index
being used.

1 files changed, 6 insertions, 0 deletions

diff --git a/spec/finders/labels_finder_spec.rb b/spec/finders/labels_finder_spec.rb
index 9abc52aa664..3f060ba0553 100644
--- a/spec/finders/labels_finder_spec.rb
+++ b/spec/finders/labels_finder_spec.rb
@@ -209,6 +209,12 @@ describe LabelsFinder do
 
         expect(finder.execute).to eq [project_label_1]
       end
+
+      it 'returns labels matching a single character' do
+        finder = described_class.new(user, search: '(')
+
+        expect(finder.execute).to eq [group_label_1]
+      end
     end
 
     context 'filter by subscription' do