Resolve "Automatically mark To-do as done when an alert is resolved"

app/services/alert_management/update_alert_status_service.rb

@@ -18,6 +18,7 @@ module AlertManagement
       return error_invalid_status unless status_key
 
       if alert.update(status_event: status_event)
+        resolve_todos if resolved?
         success
       else
         error(alert.errors.full_messages.to_sentence)
@@ -28,12 +29,16 @@ module AlertManagement
 
     attr_reader :alert, :user, :status
 
-    delegate :project, to: :alert
+    delegate :project, :resolved?, to: :alert
 
     def allowed?
       user.can?(:update_alert_management_alert, project)
     end
 
+    def resolve_todos
+      TodoService.new.resolve_todos_for_target(alert, user)
+    end
+
     def status_key
       strong_memoize(:status_key) do
         AlertManagement::Alert::STATUSES.key(status)

changelogs/unreleased/216143-resolve-todo-for-user-after-alert-resolve.yml

+---
+title: Resolve user's todo when an alert is resolved
+merge_request: 35700
+author:
+type: added

spec/services/alert_management/update_alert_status_service_spec.rb

@@ -25,7 +25,7 @@ RSpec.describe AlertManagement::UpdateAlertStatusService do
       end
     end
 
-    let(:new_status) { Types::AlertManagement::StatusEnum.values['ACKNOWLEDGED'].value }
+    let(:new_status) { AlertManagement::Alert::STATUSES[:acknowledged] }
     let(:can_update) { true }
 
     subject(:response) { service.execute }
@@ -45,6 +45,23 @@ RSpec.describe AlertManagement::UpdateAlertStatusService do
       expect { response }.to change { alert.acknowledged? }.to(true)
     end
 
+    context 'resolving status' do
+      let(:new_status) { AlertManagement::Alert::STATUSES[:resolved] }
+
+      it 'updates the status' do
+        expect { response }.to change { alert.resolved? }.to(true)
+      end
+
+      context 'user has a pending todo' do
+        let(:user) { create(:user) }
+        let!(:todo) { create(:todo, :pending, target: alert, user: user, project: alert.project) }
+
+        it 'resolves the todo' do
+          expect { response }.to change { todo.reload.state }.from('pending').to('done')
+        end
+      end
+    end
+
     context 'when user has no permissions' do
       let(:can_update) { false }