A catalogue of the most common JUnit testing mistakes with before/after code fixes. Covers testing implementation details, missing assertion messages, swapped assertEquals arguments, @SpringBootTest misuse, tests without assertions, and unseeded random data.
A performance optimization guide for slow JUnit 6 test suites. Covers measuring bottlenecks, Spring context duplication, using wrong test type, Testcontainers restarts, sequential execution, and provides a summary table with typical time savings per optimization.
A complete guide to identifying and permanently fixing flaky JUnit 6 tests. Covers all major root causes: shared mutable state, time dependency, Thread.sleep, port conflicts, file system races, order-dependent database tests, and async timing issues — each with proven fixes.
A systematic guide to debugging JUnit 6 test failures. Covers reading error messages like a pro, running tests in isolation, diagnostic assertions, IntelliJ IDEA debug techniques, common failure patterns (NPE, shared state, wrong argument order, unnecessary stubs), and a debugging toolkit table.
A systematic playbook for migrating JUnit 4 tests to JUnit 6. Covers annotation mapping, complete before/after code for @Rule, @RunWith, parameterized tests, Mockito integration, and a phase-by-phase migration strategy using the Vintage engine for zero-downtime upgrades.
A practical guide to applying Clean Code principles to JUnit 6 test code. Covers the FIRST principles, DRY vs DAMP, meaningful test structure, avoiding test smells, and real before/after refactoring examples that transform brittle tests into living documentation.
An honest comparison of the Test Pyramid and Test Trophy testing models, with JUnit 6 code examples for each approach, analysis of when each model works best, and a practical hybrid strategy for real-world Java projects.
A practical guide comparing unit, integration, and E2E tests in JUnit 6. Covers precise definitions, full code examples for each layer, speed and reliability trade-offs, recommended proportions, and guidance on when to write each type.
A complete guide to JUnit 6 test reporting: Maven Surefire HTML reports, Allure Framework with @Step and @Feature annotations, custom TestExecutionListener HTML reports, Allure in GitHub Actions CI, and guidance on choosing the right reporting tool for your audience.
A complete JaCoCo setup guide for JUnit 6 projects. Covers Maven and Gradle plugin configuration, coverage metrics explained, HTML report interpretation, enforcing minimum thresholds in CI, excluding generated code, and integrating with SonarQube.