Testcontainers

Spins up real databases, message queues, and other infrastructure in Docker containers for your integration tests instead of mocking them out. You get actual SQL Server, PostgreSQL, RabbitMQ, or whatever you need running in isolation with random ports and automatic cleanup. The big win is catching real issues like constraint violations, SQL syntax errors, and migration problems that mocks would happily let through. Works with xunit's IAsyncLifetime pattern and handles the container lifecycle so you're not manually managing Docker in your CI pipeline. If you've ever had a mock-heavy test suite pass locally only to explode in production because the real database behaves differently, this is worth the extra few seconds of container startup time.

Install to Claude Code

npx -y skills add wshaddix/dotnet-skills --skill testcontainers --agent claude-code