vitest-testing
Modern TypeScript/JavaScript testing with Vitest. Fast unit and integration tests, native ESM support, Vite-powered HMR, and comprehensive mocking. Use for testing TS/JS projects.
52
57%
Does it follow best practices?
Impact
—
No eval scenarios have been run
Passed
No known issues
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npx tessl skill review --optimize ./plugins/vitest-testing/skills/vitest-testing/SKILL.mdQuality
Discovery
50%Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.
The description identifies the tool (Vitest) and lists some of its features, but reads more like a marketing blurb for Vitest than an actionable skill description. The 'Use for' clause is too generic ('testing TS/JS projects') and doesn't provide enough trigger specificity to reliably distinguish this from other JavaScript testing skills. The description would benefit from listing concrete actions Claude performs and more explicit trigger conditions.
Suggestions
Expand the 'Use for' clause with specific trigger scenarios, e.g., 'Use when the user asks to write or run Vitest tests, mentions vitest.config, or has a project using Vitest as its test runner.'
Replace feature marketing language ('Vite-powered HMR', 'native ESM support') with concrete actions Claude performs, e.g., 'Write test files, configure vitest.config.ts, create mocks with vi.mock, set up test coverage.'
Add file extension and configuration triggers like '.test.ts', '.spec.ts', 'vitest.config.ts', 'vi.fn()', 'vi.mock()' to improve trigger term coverage and distinctiveness.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Names the domain (TypeScript/JavaScript testing with Vitest) and mentions some capabilities (unit and integration tests, ESM support, HMR, mocking), but several of these are feature descriptions of Vitest rather than concrete actions Claude would perform. It doesn't list specific actions like 'write test files', 'configure vitest.config', 'create mock implementations'. | 2 / 3 |
Completeness | The 'what' is partially covered (testing with Vitest, mocking, ESM support). There is a 'Use for' clause ('Use for testing TS/JS projects'), but it is extremely brief and generic — it doesn't provide explicit trigger conditions or scenarios that would help Claude distinguish when to select this skill over other testing skills (e.g., Jest, Mocha). | 2 / 3 |
Trigger Term Quality | Includes relevant keywords like 'Vitest', 'TypeScript', 'JavaScript', 'testing', 'unit', 'integration tests', 'mocking', 'TS/JS'. However, it misses common user variations like 'test suite', 'test runner', 'describe/it blocks', 'expect', 'vi.mock', '.test.ts', '.spec.ts', or 'coverage'. | 2 / 3 |
Distinctiveness Conflict Risk | The mention of 'Vitest' specifically helps distinguish it from generic testing skills, but the closing 'Use for testing TS/JS projects' is broad enough to conflict with Jest or other JS testing framework skills. It could be more distinctive by emphasizing Vitest-specific triggers. | 2 / 3 |
Total | 8 / 12 Passed |
Implementation
64%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a solid reference-style skill with excellent actionability—all examples are executable and concrete. However, it's somewhat verbose for Claude's needs, including well-known API references (assertions, basic mocking) that inflate token cost without adding unique value. It would benefit from trimming common knowledge, adding a clear workflow sequence, and splitting detailed reference material into separate files.
Suggestions
Remove or drastically trim the Assertions section—Claude already knows Vitest/Jest matchers. Keep only Vitest-specific or unusual patterns.
Add a clear end-to-end workflow: 'When asked to add tests to a project: 1. Check for existing vitest.config.ts, 2. Create/update config, 3. Write tests, 4. Run tests and verify passing, 5. Check coverage thresholds'.
Move detailed reference content (full assertions list, all CLI flags, mocking patterns) into a separate REFERENCE.md and keep SKILL.md as a concise overview with pointers.
Remove generic best practices Claude already follows (e.g., 'use descriptive test names', 'mock only external dependencies') and replace with project-specific or non-obvious guidance.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is mostly efficient but includes some content Claude already knows well—basic assertion matchers, standard test structure patterns, and general best practices like 'use descriptive test names' are things Claude doesn't need to be taught. The assertions section in particular is essentially a cheat sheet for well-known APIs. | 2 / 3 |
Actionability | All code examples are fully executable and copy-paste ready, from configuration to test writing to mocking to coverage commands. Specific CLI commands with flags are provided for every operation. | 3 / 3 |
Workflow Clarity | The skill covers individual aspects well but lacks a clear end-to-end workflow for setting up and running tests in a project. There's no sequenced process with validation checkpoints—e.g., no guidance on what to do when tests fail, no feedback loop for coverage threshold failures, and the sections are more reference-style than workflow-oriented. | 2 / 3 |
Progressive Disclosure | The content is well-structured with clear headers, but it's somewhat monolithic—the assertions reference, mocking patterns, and integration testing sections could be split into separate files. The 'See Also' references at the end are good but point to other skills rather than decomposing this skill's own content. | 2 / 3 |
Total | 9 / 12 Passed |
Validation
90%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 10 / 11 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
allowed_tools_field | 'allowed-tools' contains unusual tool name(s) | Warning |
Total | 10 / 11 Passed | |
- Repository
- secondsky/claude-skills
- Commit
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