unit-test-bean-validation

# Unit Testing Jakarta Bean Validation ## Overview This skill provides executable patterns for unit testing Jakarta Bean Validation annotations and custom validators using JUnit 5. Covers built-in constraints (`@NotNull`, `@Email`, `@Min`, `@Max`, `@Size`), custom `@Constraint` implementations, cross-field validation, and validation groups. Tests run in isolation without Spring context. ## When to Use - Writing unit tests for Jakarta Bean Validation or JSR-380 constraints - Testing custom `@Constraint` validators and constraint violation messages - Testing bean validation logic in DTOs and request objects - Verifying cross-field validation (e.g., password matching) - Testing conditional validation with validation groups - Fast validation tests without Spring Boot context ## Instructions 1. **Add dependencies**: Include `jakarta.validation-api` and `hibernate-validator` in test scope 2. **Create base test class**: Build `Validator` once in `@BeforeEach` using `Validation.buildDefaultValidatorFactory()` 3. **Test valid cases first**: Verify objects pass without violations 4. **Test invalid cases**: Assert constraint violations include correct property path and message 5. **Extract violation details**: Use `getPropertyPath()`, `getMessage()`, `getInvalidValue()` 6. **Test custom validators**: See `references/custom-validators.md` for patterns 7. **Use parameterized tests**: Test multiple inputs efficiently with `@ParameterizedTest` 8. **Group validation tests**: Use valida...