Micronaut unit testing

Apply fast testing strategies for Micronaut: Mockito-first, narrow @MicronautTest when HTTP or DI replacement is required.

What is covered in this Skill?

• Pure JUnit 5 + Mockito without container boot
• @MicronautTest with @MockBean factory methods for collaborators
• HttpClient blocking exchanges against the embedded server
• @Property for deterministic configuration in tests
• @ParameterizedTest with @CsvSource / @MethodSource
• Naming: *Test → Surefire; *IT → Failsafe when configured
• When to escalate to @522

Scope: Apply recommendations based on the reference rules and good/bad code examples.

Constraints

Compile before test refactors; verify the full suite after.

• MANDATORY: Run ./mvnw compile or mvn compile before applying any change
• SAFETY: If compilation fails, stop immediately
• VERIFY: Run ./mvnw clean verify or mvn clean verify after applying improvements
• BEFORE APPLYING: Read the reference for detailed rules and examples

When to use this skill

• Add or improve unit tests in a Micronaut project
• Reduce unnecessary @MicronautTest usage with Mockito-first tests

Reference

For detailed guidance, examples, and constraints, see references/521-frameworks-micronaut-testing-unit-tests.md.