1 files changed, 20 insertions, 0 deletions
diff --git a/spec/models/diff_viewer/server_side_spec.rb b/spec/models/diff_viewer/server_side_spec.rb
index 98a8f6d4cc9..86b14b6ebf3 100644
--- a/spec/models/diff_viewer/server_side_spec.rb
+++ b/spec/models/diff_viewer/server_side_spec.rb
@@ -32,4 +32,24 @@ describe DiffViewer::ServerSide do
       end
     end
   end
+
+  describe '#render_error_reason' do
+    context 'when the diff file is stored externally' do
+      before do
+        allow(diff_file).to receive(:stored_externally?).and_return(true)
+      end
+
+      it 'returns error message if stored in LFS' do
+        allow(diff_file).to receive(:external_storage).and_return(:lfs)
+
+        expect(subject.render_error_message).to include('it is stored in LFS')
+      end
+
+      it 'returns error message if stored externally' do
+        allow(diff_file).to receive(:external_storage).and_return(:foo)
+
+        expect(subject.render_error_message).to include('it is stored externally')
+      end
+    end
+  end
 end