Test-driven development flips the usual order: write the test first, then just enough code to make it pass. Philip Riecks applies that loop specifically to Spring Boot, showing how it keeps features small, focused, and easy to change later.
Why the loop works
Each short test-first cycle shapes your design, tells you what to build next, and surfaces bugs while they're still cheap to fix.
TDD across layers
- Unit tests for single classes, with small inputs and clear assertions
- Integration tests that verify endpoints, services, and data flow together
- Knowing when to mock a dependency and when to use the real thing
What you build
Features are built step by step, each one starting from a failing test and ending with working, justified code, leaving you a test suite that lets you refactor, rename, and restructure without fear of breaking things.