When Your Mocks Lie: Contract Testing with TWD

Every mock you write is a claim about what your backend returns. The moment the backend changes — a renamed field, a tightened enum, a new required property — that claim becomes a lie. Your tests still pass. Production breaks. This is mock drift, and it's invisible. You don't find out until a user hits a 500 or an empty UI in prod. The mocks that gave you confidence were the thing misleading you. TWD's contract testing closes this gap. Every mock response registered in a test gets validated agai