spring-boot-testing

name	spring-boot-testing
description	Write unit, integration, and slice tests for Spring Boot 3 applications. Use when writing unit tests, integration tests, or slice tests for Spring Boot 3 applications.
metadata	{"triggers":{"files":["**/*Test.java"],"keywords":["webmvctest","datajpatest","testcontainers","assertj"]}}

Spring Boot Testing Standards

Priority: P0 (CRITICAL)

Follow TDD Workflow

1. Red: Write failing test (e.g., returns 404).
2. Green: Implement minimal code to pass.
3. Refactor: Clean up while keeping tests green.
4. Coverage: Verify with JaCoCo.

Write Slice and Integration Tests

• Real Infrastructure: Use Testcontainers for DB/Queues. Avoid H2/Embedded.
• Assertions: Use AssertJ (assertThat) over JUnit assertions.
• Isolation: Use @MockBean for downstream dependencies in Slice Tests.

See implementation examples for WebMvcTest slice tests and Testcontainers integration tests.

Anti-Patterns

• No Dirty Contexts: Avoid @MockBean in base classes; it reloads context per test.
• No network I/O in tests: Mock external calls with WireMock.
• No System.out in tests: Use AssertJ assertions instead.

References

• Implementation Examples