Optimise upload path calls

String#underscore isn't particularly slow, but it's possible for us to
call it many times in a users autocomplete request, with mostly-static
values ('User', 'Group', etc.). We can memoise this and save a
surprising amount of time (around 10% of the total request time in some
cases).

1 files changed, 6 insertions, 0 deletions

diff --git a/spec/models/application_record_spec.rb b/spec/models/application_record_spec.rb
index cc90a998d3f..74573d0941c 100644
--- a/spec/models/application_record_spec.rb
+++ b/spec/models/application_record_spec.rb
@@ -52,4 +52,10 @@ describe ApplicationRecord do
       expect { Suggestion.find_or_create_by!(note: nil) }.to raise_error(ActiveRecord::RecordInvalid)
     end
   end
+
+  describe '.underscore' do
+    it 'returns the underscored value of the class as a string' do
+      expect(MergeRequest.underscore).to eq('merge_request')
+    end
+  end
 end