1 files changed, 64 insertions, 0 deletions
diff --git a/spec/services/merge_requests/reload_diffs_service_spec.rb b/spec/services/merge_requests/reload_diffs_service_spec.rb
new file mode 100644
index 00000000000..a0a27d247fc
--- /dev/null
+++ b/spec/services/merge_requests/reload_diffs_service_spec.rb
@@ -0,0 +1,64 @@
+require 'spec_helper'
+
+describe MergeRequests::ReloadDiffsService, :use_clean_rails_memory_store_caching do
+  let(:current_user) { create(:user) }
+  let(:merge_request) { create(:merge_request) }
+  let(:subject) { described_class.new(merge_request, current_user) }
+
+  describe '#execute' do
+    it 'creates new merge request diff' do
+      expect { subject.execute }.to change { merge_request.merge_request_diffs.count }.by(1)
+    end
+
+    it 'calls update_diff_discussion_positions with correct params' do
+      old_diff_refs = merge_request.diff_refs
+      new_diff = merge_request.create_merge_request_diff
+      new_diff_refs = merge_request.diff_refs
+
+      expect(merge_request).to receive(:create_merge_request_diff).and_return(new_diff)
+      expect(merge_request).to receive(:update_diff_discussion_positions)
+        .with(old_diff_refs: old_diff_refs,
+              new_diff_refs: new_diff_refs,
+              current_user: current_user)
+
+      subject.execute
+    end
+
+    it 'does not change existing merge request diff' do
+      expect(merge_request.merge_request_diff).not_to receive(:save_git_content)
+
+      subject.execute
+    end
+
+    context 'cache clearing' do
+      before do
+        allow_any_instance_of(Gitlab::Diff::File).to receive(:text?).and_return(true)
+        allow_any_instance_of(Gitlab::Diff::File).to receive(:diffable?).and_return(true)
+      end
+
+      it 'retrieves the diff files to cache the highlighted result' do
+        new_diff = merge_request.create_merge_request_diff
+        cache_key = new_diff.diffs_collection.cache_key
+
+        expect(merge_request).to receive(:create_merge_request_diff).and_return(new_diff)
+        expect(Rails.cache).to receive(:read).with(cache_key).and_call_original
+        expect(Rails.cache).to receive(:write).with(cache_key, anything, anything).and_call_original
+
+        subject.execute
+      end
+
+      it 'clears the cache for older diffs on the merge request' do
+        old_diff = merge_request.merge_request_diff
+        old_cache_key = old_diff.diffs_collection.cache_key
+        new_diff = merge_request.create_merge_request_diff
+        new_cache_key = new_diff.diffs_collection.cache_key
+
+        expect(merge_request).to receive(:create_merge_request_diff).and_return(new_diff)
+        expect(Rails.cache).to receive(:delete).with(old_cache_key).and_call_original
+        expect(Rails.cache).to receive(:read).with(new_cache_key).and_call_original
+        expect(Rails.cache).to receive(:write).with(new_cache_key, anything, anything).and_call_original
+        subject.execute
+      end
+    end
+  end
+end