testcontainers

You can run integration tests against real databases by using Docker containers to spin up live dependencies like PostgreSQL or SQL Server. This approach manages container startup and cleanup automatically, providing isolated, production-like environments for your tests.

Isolating integration tests with message brokers and caches is achieved by launching individual Docker containers per test. Each test gets a fresh, isolated instance of dependencies like RabbitMQ, Kafka, or Redis, preventing state leakage across test runs.

Testcontainers for .NET provides automated lifecycle management by handling the creation, startup, and cleanup of Docker containers. This ensures dependencies are instantiated and removed automatically, eliminating manual container orchestration during test execution.

You can test a data access layer by launching a PostgreSQL container, applying database migrations, and executing repository methods against the live database. This validates your data access logic using a real, containerized PostgreSQL instance.

Using real infrastructure dependencies instead of mocks ensures tests run against production-like environments. Spinning up actual databases, message queues, and caches in Docker containers validates integration points and catches issues that mocking frameworks often miss.