1 files changed, 43 insertions, 0 deletions
diff --git a/spec/services/design_management/design_user_notes_count_service_spec.rb b/spec/services/design_management/design_user_notes_count_service_spec.rb
new file mode 100644
index 00000000000..62211a4dd0f
--- /dev/null
+++ b/spec/services/design_management/design_user_notes_count_service_spec.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe DesignManagement::DesignUserNotesCountService, :use_clean_rails_memory_store_caching do
+  let_it_be(:design) { create(:design, :with_file) }
+
+  subject { described_class.new(design) }
+
+  it_behaves_like 'a counter caching service'
+
+  describe '#count' do
+    it 'returns the count of notes' do
+      create_list(:diff_note_on_design, 3, noteable: design)
+
+      expect(subject.count).to eq(3)
+    end
+  end
+
+  describe '#cache_key' do
+    it 'contains the `VERSION` and `design.id`' do
+      expect(subject.cache_key).to eq(['designs', 'notes_count', DesignManagement::DesignUserNotesCountService::VERSION, design.id])
+    end
+  end
+
+  describe 'cache invalidation' do
+    it 'changes when a new note is created' do
+      new_note_attrs = attributes_for(:diff_note_on_design, noteable: design)
+
+      expect do
+        Notes::CreateService.new(design.project, create(:user), new_note_attrs).execute
+      end.to change { subject.count }.by(1)
+    end
+
+    it 'changes when a note is destroyed' do
+      note = create(:diff_note_on_design, noteable: design)
+
+      expect do
+        Notes::DestroyService.new(note.project, note.author).execute(note)
+      end.to change { subject.count }.by(-1)
+    end
+  end
+end