1 files changed, 70 insertions, 0 deletions
diff --git a/spec/services/resource_events/merge_into_notes_service_spec.rb b/spec/services/resource_events/merge_into_notes_service_spec.rb
new file mode 100644
index 00000000000..0d333d541c9
--- /dev/null
+++ b/spec/services/resource_events/merge_into_notes_service_spec.rb
@@ -0,0 +1,70 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe ResourceEvents::MergeIntoNotesService do
+  def create_event(params)
+    event_params = { action: :add, label: label, issue: resource,
+                     user: user }
+
+    create(:resource_label_event, event_params.merge(params))
+  end
+
+  def create_note(params)
+    opts = { noteable: resource, project: project }
+
+    create(:note_on_issue, opts.merge(params))
+  end
+
+  set(:project)  { create(:project) }
+  set(:user)   { create(:user) }
+  set(:resource) { create(:issue, project: project) }
+  set(:label) { create(:label, project: project) }
+  set(:label2) { create(:label, project: project) }
+  let(:time) { Time.now }
+
+  describe '#execute' do
+    it 'merges label events into notes in order of created_at' do
+      note1 = create_note(created_at: 4.days.ago)
+      note2 = create_note(created_at: 2.days.ago)
+      event1 = create_event(created_at: 3.days.ago)
+      event2 = create_event(created_at: 1.day.ago)
+
+      notes = described_class.new(resource, user).execute([note1, note2])
+
+      expected = [note1, event1, note2, event2].map(&:discussion_id)
+      expect(notes.map(&:discussion_id)).to eq expected
+    end
+
+    it 'squashes events with same time and author into single note' do
+      user2 = create(:user)
+
+      create_event(created_at: time)
+      create_event(created_at: time, label: label2, action: :remove)
+      create_event(created_at: time, user: user2)
+      create_event(created_at: 1.day.ago, label: label2)
+
+      notes = described_class.new(resource, user).execute()
+
+      expected = [
+        "added #{label.to_reference} label and removed #{label2.to_reference} label",
+        "added #{label.to_reference} label",
+        "added #{label2.to_reference} label"
+      ]
+
+      expect(notes.count).to eq 3
+      expect(notes.map(&:note)).to match_array expected
+    end
+
+    it 'fetches only notes created after last_fetched_at' do
+      create_event(created_at: 4.days.ago)
+      event = create_event(created_at: 1.day.ago)
+
+      notes = described_class.new(resource, user,
+                                  last_fetched_at: 2.days.ago.to_i).execute()
+
+      expect(notes.count).to eq 1
+      expect(notes.first.discussion_id).to eq event.discussion_id
+    end
+  end
+end