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
83
78%
Does it follow best practices?
Impact
Pending
No eval scenarios have been run
Passed
No known issues
Optimize this skill with Tessl
npx tessl skill review --optimize ./skills/131-java-testing-unit-testing/SKILL.mdQuality
Discovery
100%Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.
This is a strong skill description that clearly communicates its purpose with an explicit 'Use when' trigger clause, lists numerous specific capabilities and frameworks, and uses natural keywords Java developers would employ. The description is highly distinctive due to its narrow focus on Java unit testing with named tools and methodologies, making it easy to differentiate from other skills.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists numerous specific concrete actions: migrating JUnit 4 to JUnit 5, adopting AssertJ, structuring with Given-When-Then, applying parameterized tests, mocking with Mockito, verifying boundary conditions, leveraging JSpecify annotations, eliminating anti-patterns like reflection-based tests or shared mutable state. | 3 / 3 |
Completeness | Opens with an explicit 'Use when' clause that clearly answers both what (review, improve, write Java unit tests with specific techniques) and when (migrating JUnit versions, adopting AssertJ, structuring tests, mocking, etc.). The trigger guidance is explicit and comprehensive. | 3 / 3 |
Trigger Term Quality | Excellent coverage of natural terms users would say: 'unit tests', 'JUnit 4', 'JUnit 5', 'AssertJ', 'Mockito', 'parameterized tests', 'mocking dependencies', 'Given-When-Then', 'null-safety', 'JSpecify', 'testing anti-patterns'. These are terms Java developers naturally use when seeking testing help. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive — narrowly scoped to Java unit testing with specific frameworks (JUnit 4/5, AssertJ, Mockito, JSpecify) and methodologies (RIGHT-BICEP, CORRECT, A-TRIP). Unlikely to conflict with general coding skills or non-Java testing skills. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
57%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
The skill has good structure and progressive disclosure, correctly delegating detailed patterns to a reference file while keeping the overview lean. Its main weaknesses are the lack of any concrete code examples in the skill body itself (making it hard to act on without reading the reference) and a workflow that, while present, lacks a complete feedback loop for post-verification failures. The bullet list of topics covered is borderline unnecessary given the reference file exists.
Suggestions
Add at least one concrete before/after code example (e.g., JUnit 4 → JUnit 5 migration or an AssertJ assertion pattern) directly in the skill body so Claude has immediately actionable guidance without needing to read the reference.
Expand the workflow into a numbered sequence that includes what to do if `clean verify` fails after applying changes (feedback loop for test failures, not just compilation failures).
Consider condensing or removing the 'What is covered' bullet list — it largely duplicates the reference file's table of contents and doesn't add actionable value.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The 'What is covered' bullet list is essentially a table of contents for the reference file and adds moderate value, but the introductory line and scope statement are somewhat redundant. The content is not egregiously verbose but could be tightened — e.g., the bullet list could be removed or condensed since it mostly restates the description. | 2 / 3 |
Actionability | The constraints section provides concrete commands (`./mvnw compile`, `./mvnw clean verify`) which is good, but the skill body contains zero code examples, no concrete test patterns, and no executable guidance — it entirely delegates to the reference file. Claude would need to read the reference to do anything useful. | 2 / 3 |
Workflow Clarity | There is a clear compile-before/verify-after workflow with an explicit blocking condition on compilation failure, which is good. However, the steps are not fully sequenced (no numbered workflow), and there's no feedback loop for what to do if `clean verify` fails after applying changes. | 2 / 3 |
Progressive Disclosure | The skill is structured as a concise overview with a single, clearly signaled reference file for detailed examples and patterns. Navigation is one level deep and well-organized with clear section headers. | 3 / 3 |
Total | 9 / 12 Passed |
Validation
100%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 11 / 11 Passed
Validation for skill structure
No warnings or errors.
- Repository
- jabrena/cursor-rules-java
- Commit
9ec21dd
- Reviewed
Table of Contents
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