copilot-setting testing.instructions.md

Testing Conventions

Java 8 language rules apply: instructions/java.instructions.md.

Framework Boundary (JUnit 5 / Spring Boot Forbidden)

• JUnit 4 — org.junit.Test, @Before / @After, Assert.assertEquals. No org.junit.jupiter.* / @BeforeEach / @ExtendWith
• Spring Test 3.2 — @RunWith(SpringJUnit4ClassRunner.class) + @ContextConfiguration. No @SpringBootTest / @WebMvcTest / @ExtendWith(SpringExtension.class)
• Mockito — @RunWith(MockitoJUnitRunner.class) or MockitoAnnotations.initMocks(this). No @ExtendWith(MockitoExtension.class)
• Assertions: Assert.* or Hamcrest assertThat; AssertJ only if already on the classpath

Structure

• One behavior per test; name methodName_condition_expectedResult; Arrange–Act–Assert, visually separated
• No interdependence (isolated, any order); no logic (loops / conditionals) inside a test

Integration Tests

• @ContextConfiguration against a test-scoped XML context, not production beans
• Test-class @Transactional auto-rollback is sanctioned — test-only; does NOT violate the production <tx:advice>-only rule (instructions/spring-hibernate.instructions.md)
• Never hit a real external service — stub at the boundary

Data & Mocks

• Mock collaborators at the layer boundary (DAO in service tests); no shared mutable static fixtures
• Deterministic: no new Date() / unseeded random — inject a fixed clock or seed

Anti-Patterns

Pattern	Problem	Fix
org.junit.jupiter.api.Test	JUnit 5	org.junit.Test
@SpringBootTest	No Spring Boot	@RunWith(SpringJUnit4ClassRunner.class) + @ContextConfiguration
@BeforeEach / @AfterEach	JUnit 5 lifecycle	@Before / @After
@ExtendWith(MockitoExtension.class)	JUnit 5 extension	@RunWith(MockitoJUnitRunner.class)
Thread.sleep() for async	Flaky, slow	Await a condition / synchronous executor