Contract Testing: The secret to fast microservices.
Verify that your applications work together without the pain of end-to-end tests. Contract testing provides the speed of unit tests with the confidence of integration tests.
What is Contract Testing?
Contract testing is a methodology for ensuring that two separate systems (such as two microservices) are compatible and can communicate with each other. It captures the interactions between a consumer and a provider and stores them in a "contract".
By verifying these contracts independently, you can be sure that a change in one service won't break another, without ever having to deploy them both to a shared environment.
Why you need it
In a microservices architecture, traditional integration tests become a bottleneck. They are slow, flaky, and hard to maintain. Contract testing solves this by:
- Eliminating "Release Trains"
- Providing instant feedback to developers
- Reducing environment costs
- Documenting your APIs automatically
Contract Testing with Deployagram
Deployagram makes contract testing visual and effortless. Instead of writing complex DSLs, Deployagram reuses your existing tests to generate contracts automatically.
See at a glance which versions of your services are compatible across HTTP and Kafka, and drill down into the exact payloads that caused a failure.
Frequently Asked Questions
Is it better than E2E testing?
Contract tests are faster and more reliable. While E2E tests check the whole system, contract tests check the boundaries, catching integration issues in seconds.
Why does it suit microservices?
Microservices are not meant to be tested together as this takes away "independent deployability" - a key benefit of microservices. Contract testing allows for independent testing of microservices, ensuring that each service can be deployed and tested in isolation.
Does it support Kafka?
Yes! Deployagram supports both synchronous (HTTP) and asynchronous (Kafka) interactions for comprehensive contract coverage.
How do I get started?
You can start by instrumenting your existing JUnit5 or Spring Boot tests. Deployagram handles the rest.
Do I have to write more tests?
With Deployagram, existing Service tests are all that are required! Now you can delete those clumsy E2E tests!
Do I have to write client or server first?
Either way works just fine - whatever works for your development team!