131-java-testing-unit-testing
Use when you need to review, improve, or write Java unit tests — including migrating from JUnit 4 to JUnit 5, adopting AssertJ for fluent assertions, structuring tests with Given-When-Then, ensuring test independence, applying parameterized tests, mocking dependencies with Mockito, verifying boundary conditions (RIGHT-BICEP, CORRECT, A-TRIP), leveraging JSpecify null-safety annotations, or eliminating testing anti-patterns such as reflection-based tests or shared mutable state. Part of the skills-for-java project
ソース情報
- リポジトリ
- jabrena/cursor-rules-examples
- ソースの最終更新活動
- 2026年3月19日 20:26
- 検出された SKILL.md の言語
- 英語
- スター
- 2
- フォーク
- 3
インストール方法
デフォルトでは、最初にソースを確認する Prompt が選択されています。直接コマンドに切り替えるか、ローカルコピーをダウンロードすることもできます。
ソースファイルを確認
インストールを決める前に、SKILL.md と SkillsMP に表示されている付属ファイルをお読みください。
ファイルエクスプローラー
2 ファイルSKILL.md を表示中
SKILL.md
ソースの指示 · 読み取り専用プレビュー- name
- 131-java-testing-unit-testing
- description
- Use when you need to review, improve, or write Java unit tests — including migrating from JUnit 4 to JUnit 5, adopting AssertJ for fluent assertions, structuring tests with Given-When-Then, ensuring test independence, applying parameterized tests, mocking dependencies with Mockito, verifying boundary conditions (RIGHT-BICEP, CORRECT, A-TRIP), leveraging JSpecify null-safety annotations, or eliminating testing anti-patterns such as reflection-based tests or shared mutable state. Part of the skills-for-java project
- license
- Apache-2.0
- metadata
- {"author":"Juan Antonio Breña Moral","version":"0.13.0-SNAPSHOT"}
# Java Unit testing guidelines
Review and improve Java unit tests using modern JUnit 5, AssertJ, and Mockito best practices.
**What is covered in this Skill?**
- JUnit 5 annotations: `@Test`, `@BeforeEach`, `@AfterEach`, `@DisplayName`, `@Nested`, `@ParameterizedTest`
- AssertJ fluent assertions: `assertThat`, `assertThatThrownBy`
- Given-When-Then test structure, descriptive test naming, single-responsibility tests
- Test independence and isolated state
- Parameterized tests: `@ValueSource`/`@CsvSource`/`@MethodSource`
- Mockito dependency mocking: `@Mock`, `@InjectMocks`, `MockitoExtension`
- Code coverage guidance (JaCoCo), package-private test visibility
- Testing anti-patterns: reflection, shared state, hard-coded values, testing implementation details
- Error handling: `assertThatThrownBy`, exception messages
- JSpecify null-safety: `@NullMarked`, `@Nullable`
- RIGHT-BICEP coverage principles, A-TRIP test quality, CORRECT boundary condition verification
**Scope:** The reference is organized by examples (good/bad code patterns) for each core area. Apply recommendations based on applicable examples.
## Constraints
Before applying any unit test changes, ensure the project compiles. If compilation fails, stop immediately — do not proceed until resolved. After applying improvements, run full verification.
- **MANDATORY**: Run `./mvnw compile` or `mvn compile` before applying any change
- **SAFETY**: If compilation fails, stop immediately and do not proceed — compilation failure is a blocking condition
- **VERIFY**: Run `./mvnw clean verify` or `mvn clean verify` after applying improvements
- **BEFORE APPLYING**: Read the reference for detailed examples, good/bad patterns, and constraints
## When to use this skill
- Review Java code for unit tests
- Apply best practices for unit tests in Java code
## Reference
For detailed guidance, examples, and constraints, see [references/131-java-testing-unit-testing.md](references/131-java-testing-unit-testing.md).
GitHubで見る