1 files changed, 17 insertions, 0 deletions
diff --git a/spec/services/merge_requests/merge_request_diff_cache_service_spec.rb b/spec/services/merge_requests/merge_request_diff_cache_service_spec.rb
new file mode 100644
index 00000000000..807f89e80b7
--- /dev/null
+++ b/spec/services/merge_requests/merge_request_diff_cache_service_spec.rb
@@ -0,0 +1,17 @@
+require 'spec_helper'
+
+describe MergeRequests::MergeRequestDiffCacheService do
+  let(:subject) { MergeRequests::MergeRequestDiffCacheService.new }
+
+  describe '#execute' do
+    it 'retrieves the diff files to cache the highlighted result' do
+      merge_request = create(:merge_request)
+      cache_key = [merge_request.merge_request_diff, 'highlighted-diff-files', Gitlab::Diff::FileCollection::MergeRequestDiff.default_options]
+
+      expect(Rails.cache).to receive(:read).with(cache_key).and_return({})
+      expect(Rails.cache).to receive(:write).with(cache_key, anything)
+
+      subject.execute(merge_request)
+    end
+  end
+end