TestContainers solves the challenge of writing isolated integration tests by spinning up real Docker containers for external dependencies like databases and message brokers. The post walks through setting up a PostgreSQL TestContainer in a .NET project, integrating it with ASP.NET's WebApplicationFactory, applying EF migrations, and writing end-to-end integration tests using TUnit. Key benefits include test isolation, consistency, and a self-contained test suite that runs identically in CI pipelines without mocks or shared test instances.
Table of contents
Why TestContainersPrerequisitesInstall TestContainersCreating a test containerIntegrating a test container in your testsApplying EF migrationsExample test caseWhat about the CI pipeline?Conclusion2 Impressions