spring-boot-testing

This skill provides expert guide for testing Spring Boot 4 applications with modern patterns and best practices. When a method or class is too complex to test effectively: Example of refactoring recommendation: Create helper methods for commonly used objects and mock setup to enhance readability and maintainability. Use descriptive display names to clarify test intent: Always structure tests in this order: Write tests with real production scenarios in mind. This makes tests more relatable and helps understand code behavior in actual production cases. Aim for 80% code coverage as a practical balance between quality and effort. Higher coverage is beneficial but not the only goal. Use Jacoco maven plugin for coverage reporting and tracking. Coverage Rules: What to Prioritize: - Test Pyramid : Unit (fast) > Slice (focused) > Integration (complete) - Right Tool : Use the narrowest slice that gives you confidence - AssertJ Style : Fluent, readable assertions over verbose matchers - Modern APIs : Prefer MockMvcTester and RestTestClient over legacy alternatives - references/test-slices-overview.md - Decision matrix and comparison - references/webmvctest.md - Web layer with MockMvc - references/datajpatest.md - Data layer with Testcontainers - references/restclienttest.md - REST client testing - references/mockmvc-tester.md - AssertJ-style MockMvc (3.2+) - references/mockmvc-classic.md...