Java Test

Generate Java Tests

Generate JUnit5 tests for the given class or method using AssertJ assertions and Mockito mocking.

What To Do

1. Read the target class to understand public methods, dependencies, and edge cases
2. Generate test class with @ExtendWith(MockitoExtension.class)
3. Mock dependencies with @Mock and inject with @InjectMocks
4. Write tests following Arrange-Act-Assert pattern
5. Cover edge cases: null inputs, empty collections, boundary values, exceptions

Test Types

Unit Test (default)

• @ExtendWith(MockitoExtension.class)
• Mock all dependencies with Mockito
• Test one method per test, one concept per assertion

Integration Test (--type=integration)

• @SpringBootTest with Testcontainers
• @DynamicPropertySource for database connection
• Real database operations, no mocking
• @Transactional for auto-rollback

Controller Test (--type=controller)

• @WebMvcTest({Controller}.class)
• MockMvc for HTTP request/response testing
• @MockBean for service dependencies
• Test status codes, response body, validation errors

Conventions

• @DisplayName("should {expected} when {scenario}")
• @Nested inner classes for grouping by method or scenario
• @ParameterizedTest for data-driven tests
• assertThat() from AssertJ (not assertEquals)
• verify() for interaction verification
• assertThatThrownBy() for exception testing

Arguments

• <class-or-method>: Target class or method name
• --type=<unit|integration|controller>: Test type (default: unit)