From Jest to Vitest: Pragmatic Integration Testing for Node.js Applications

As developers transition from Jest to Vitest, the real challenge lies in writing meaningful integration tests rather than over-mocked unit tests. This guide demonstrates how to adopt Rails-inspired patterns—using factories and containerized dependencies like PostgreSQL and Redis—to validate both application logic and database persistence. By moving beyond surface-level testing, teams can catch integration issues before production and build more reliable applications.