Use when you need to write unit tests for Spring Boot applications — including pure unit tests with @ExtendWith(MockitoExtension.class) for @Service/@Component, slice tests with @WebMvcTest and @MockitoBean for controllers, @JsonTest for JSON serialization, parameterized tests with @CsvSource/@MethodSource, test profiles, and @TestConfiguration. For framework-agnostic Java use @131-java-testing-unit-testing. For integration tests use @322-frameworks-spring-boot-testing-integration-tests. This s…
Use when you need to write unit tests for Spring Boot applications — including pure unit tests with @ExtendWith(MockitoExtension.class) for @Service/@Component, slice tests with @WebMvcTest and @MockitoBean for controllers, @JsonTest for JSON serialization, parameterized tests with @CsvSource/@MethodSource, test profiles, and @TestConfiguration.
For framework-agnostic Java use @131-java-testing-unit-testing.
For integration tests use @322-frameworks-spring-boot-testing-integration-tests.
This should trigger for requests such as Review Java code for Spring Boot unit tests; Apply best practices for Spring Boot unit tests in Java code; Write Mockito-first unit tests for Spring Boot services; Avoid unnecessary @SpringBootTest in Spring unit tests; Review Spring Boot slice-free unit test design.
Part of Plinth Toolkit
Similar popular skills
Related neighbors and high-traction skills in the same topics — useful to compare before installing.
@JsonTest for JSON serialization with correct JSON value assertions (extractingJsonPathStringValue, etc.)
Parameterized tests: @ParameterizedTest with @CsvSource or @MethodSource over copy-pasted methods
Java records for domain objects in tests
@TestConfiguration, @ActiveProfiles, @Primary fixed-clock beans for deterministic test setup
Modern mocking API: @MockitoBean / @MockitoSpyBean; @MockBean/@SpyBean are deprecated/removed in Boot 4.0.x
Scope: Apply recommendations based on the reference rules and good/bad code examples. For integration tests use @322-frameworks-spring-boot-testing-integration-tests.
Constraints
Before applying any test changes, ensure the project compiles. If compilation fails, stop immediately. After applying improvements, run full verification.
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 good/bad patterns
EDGE CASE: If request scope is ambiguous, stop and ask a clarifying question before applying changes
EDGE CASE: If required inputs, files, or tooling are missing, report what is missing and ask whether to proceed with setup guidance
When to use this skill
Review Java code for Spring Boot unit tests
Apply best practices for Spring Boot unit tests in Java code
Write Mockito-first unit tests for Spring Boot services
Avoid unnecessary @SpringBootTest in Spring unit tests
Review Spring Boot slice-free unit test design
Workflow
Read reference and assess project context
Read references/321-frameworks-spring-boot-testing-unit-tests.md and inspect the current project setup before proposing changes.
Gather scope and decide target improvements
Identify requested outcomes, constraints, and the minimum safe set of changes to apply.
Apply framework-aligned changes
Implement or refactor configuration/code following the reference patterns and project conventions.
Run verification and report results
Execute appropriate build/tests and summarize what changed, what was verified, and any follow-up actions.
Reference
For detailed guidance, examples, and constraints, see [references/321-frameworks-spring-boot-testing-unit-tests.md](references/321-frameworks-spring-boot-testing-unit-tests.md).
