spring-boot-test-patterns

Spring Boot testing patterns guide you through unit, slice, and integration test setup using annotations like @SpringBootTest, @DataJpaTest, and @WebMvcTest. This Skill consolidates layered testing guidance with Mockito, Testcontainers, and MockMvc to help you build fast, reliable test suites across monoliths and microservices.

Testcontainers run real service instances in Docker for integration tests, ensuring accurate environment behavior; Mockito mocks dependencies for unit tests. Use Testcontainers for database, messaging, and external service testing; use mocks for isolated unit tests. This Skill covers both patterns and when to apply each.

Slice tests load only the components you need—@WebMvcTest for web layers, @DataJpaTest for persistence layers—reducing startup time and complexity. This Skill provides setup patterns and best practices for each annotation to build maintainable, focused test suites without full application context.

CI/CD testing requires proper dependency management, plugin configuration, and Testcontainers setup in build files. This Skill includes sample Maven and Gradle configurations that ensure reproducible, containerized tests across environments with best practices for observability and maintainability.

MockMvc tests Spring MVC applications synchronously; WebTestClient tests WebFlux and reactive applications. This Skill covers both tools and demonstrates how to apply the right client for your Spring Boot architecture—servlet or reactive—with example patterns and setup guidance.

Common issues include slow test startup, flaky container setup, and poor test isolation. This Skill addresses observability, maintainability, and robust test design to help you avoid these pitfalls and build repeatable test suites that scale with your application.