1 files changed, 8 insertions, 0 deletions
diff --git a/spec/models/merge_request_diff_file_spec.rb b/spec/models/merge_request_diff_file_spec.rb
index 5a48438adab..c9bcb900eca 100644
--- a/spec/models/merge_request_diff_file_spec.rb
+++ b/spec/models/merge_request_diff_file_spec.rb
@@ -85,5 +85,13 @@ RSpec.describe MergeRequestDiffFile do
 
       expect { subject.utf8_diff }.not_to raise_error
     end
+
+    it 'calls #diff once' do
+      allow(subject).to receive(:diff).and_return('test')
+
+      expect(subject).to receive(:diff).once
+
+      subject.utf8_diff
+    end
   end
 end