What is Integration Test?
Turkish: Entegrasyon Testi
Integration testing verifies the expected data flow when multiple modules, services, or external systems work together.
What Is an Integration Test?
An integration test checks whether parts that work correctly on their own also produce the right result together. A payment service, order module, stock table, and email notification can each pass isolated tests; integration testing verifies that the shared flow moves data without breaking.
Unit tests focus on functions or classes. Integration tests can involve a real database, message queue, file system, API client, or third-party service contract. They do not always need every dependency to be live; teams may use a test database, fake service, contract test, or temporary containerized dependency.
What Gets Tested?
Common scenarios include sending an email queue message after registration, changing order state after a successful payment response, updating stock through an ERP integration, and returning the right status code for authorization failures. Failure paths matter as much as happy paths.
Place in the Test Pyramid
Integration tests may be slower than unit tests, but they are more targeted than relying only on end-to-end tests. An E2E test validates a user journey, while an integration test catches data exchange problems at a specific system boundary.