contract-testing-builder

API contract testing prevents breaking changes by defining expectations from the consumer's perspective and verifying the provider meets those expectations. This validates provider-consumer compatibility before deployment.

Automating API contract verification in a CI/CD pipeline involves integrating contract tests that continuously validate provider implementations against consumer-defined pacts and OpenAPI specifications during the build process.

Yes, you can validate API requests and responses against an OpenAPI specification. This process uses JSON Schema to validate data structures and ensures the API conforms to its defined contract.

Consumer-driven contract testing with Pact works by having consumers define their expectations in a pact file. The provider then verifies its API against this pact to ensure it fulfills the consumer's requirements without breaking compatibility.

While consumer-driven pacts define specific interactions, having an OpenAPI specification allows you to perform comprehensive schema validation. The specification acts as a source of truth to validate API requests and responses alongside pact verification.

Use contract testing when developing new API versions to ensure existing applications consuming the API will not break. It specifically targets provider-consumer compatibility and unexpected changes in API behavior, complementing standard functional tests.