1 files changed, 70 insertions, 0 deletions

diff --git a/spec/services/issues/update_service_spec.rb b/spec/services/issues/update_service_spec.rb
index ce20bf2bef6..ef76e2311b1 100644
--- a/spec/services/issues/update_service_spec.rb
+++ b/spec/services/issues/update_service_spec.rb
@@ -543,6 +543,76 @@ describe Issues::UpdateService, :mailer do
       end
     end
 
+    context 'when updating a single task' do
+      before do
+        update_issue(description: "- [ ] Task 1\n- [ ] Task 2")
+      end
+
+      it { expect(issue.tasks?).to eq(true) }
+
+      context 'when a task is marked as completed' do
+        before do
+          update_issue(update_task: { index: 1, checked: true, line_source: '- [ ] Task 1', line_number: 1 })
+        end
+
+        it 'creates system note about task status change' do
+          note1 = find_note('marked the task **Task 1** as completed')
+
+          expect(note1).not_to be_nil
+
+          description_notes = find_notes('description')
+          expect(description_notes.length).to eq(1)
+        end
+      end
+
+      context 'when a task is marked as incomplete' do
+        before do
+          update_issue(description: "- [x] Task 1\n- [X] Task 2")
+          update_issue(update_task: { index: 2, checked: false, line_source: '- [X] Task 2', line_number: 2 })
+        end
+
+        it 'creates system note about task status change' do
+          note1 = find_note('marked the task **Task 2** as incomplete')
+
+          expect(note1).not_to be_nil
+
+          description_notes = find_notes('description')
+          expect(description_notes.length).to eq(1)
+        end
+      end
+
+      context 'when the task position has been modified' do
+        before do
+          update_issue(description: "- [ ] Task 1\n- [ ] Task 3\n- [ ] Task 2")
+        end
+
+        it 'raises an exception' do
+          expect(Note.count).to eq(2)
+          expect do
+            update_issue(update_task: { index: 2, checked: true, line_source: '- [ ] Task 2', line_number: 2 })
+          end.to raise_error(ActiveRecord::StaleObjectError)
+          expect(Note.count).to eq(2)
+        end
+      end
+
+      context 'when the content changes but not task line number' do
+        before do
+          update_issue(description: "Paragraph\n\n- [ ] Task 1\n- [x] Task 2")
+          update_issue(description: "Paragraph with more words\n\n- [ ] Task 1\n- [x] Task 2")
+          update_issue(update_task: { index: 2, checked: false, line_source: '- [x] Task 2', line_number: 4 })
+        end
+
+        it 'creates system note about task status change' do
+          note1 = find_note('marked the task **Task 2** as incomplete')
+
+          expect(note1).not_to be_nil
+
+          description_notes = find_notes('description')
+          expect(description_notes.length).to eq(2)
+        end
+      end
+    end
+
     context 'updating labels' do
       let(:label3) { create(:label, project: project) }
       let(:result) { described_class.new(project, user, params).execute(issue).reload }