pact-js

pact-js is the JavaScript implementation of Pact, a contract testing framework that enables developers to verify HTTP APIs and asynchronous messaging systems by defining and testing consumer-driven contracts between services. It is designed for teams building microservices or distributed systems who want to ensure service compatibility without brittle end-to-end tests. The project is interesting because it shifts testing left, allowing developers to catch integration issues early and safely evolve APIs with confidence.