Spring Boot Testing

Expert guide for testing Spring Boot 4 applications with modern patterns and best practices.

Core Principles

1. Test Pyramid: Unit (fast) > Slice (focused) > Integration (complete)
2. Right Tool: Use the narrowest slice that gives you confidence
3. AssertJ Style: Fluent, readable assertions over verbose matchers
4. Modern APIs: Prefer MockMvcTester and RestTestClient over legacy alternatives

Which Test Slice?