java-springboot-testing

Configure a Testcontainers-backed @DataJpaTest by spinning up a database container within your test setup. This approach ensures production parity for repository testing without the overhead of loading a full Spring Boot application context.

AssertJ provides fluent, readable assertions for Spring Boot tests by chaining assertion methods like assertThat(object).fieldisEqualTo(value). This skill guides modern assertion patterns to replace standard JUnit assertions for clearer test failure reporting.

Spring Boot testing fully supports JUnit 5 and Mockito for mock management. You can use MockitoBean to inject mocks into your test slices, ensuring isolated unit testing of specific components without external dependencies.

The best way to test a Spring Boot REST controller is using MockMvcTester for modern web layer testing. This skill guides generating test classes with MockMvcTester and MockitoBean to validate HTTP request and response mappings efficiently.

Use @SpringBootTest instead of narrow test slices when you need to test the full application context or validate integration across multiple layers. Narrow slices like @WebMvcTest are better for isolated, fast component tests to avoid unnecessary overhead.