javascript-testing-patterns
Implement comprehensive testing strategies using Jest, Vitest, and Testing Library for unit tests, integration tests, and end-to-end testing with mocking, fixtures, and test-driven development. Use when writing JavaScript/TypeScript tests, setting up test infrastructure, or implementing TDD/BDD workflows.
60
71%
Does it follow best practices?
Impact
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Optimize this skill with Tessl
npx tessl skill review --optimize ./tests/ext_conformance/artifacts/agents-wshobson/javascript-typescript/skills/javascript-testing-patterns/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 articulates specific capabilities (testing with named frameworks and methodologies), includes abundant natural trigger terms users would use, and provides explicit 'Use when' guidance. It uses proper third-person voice and is concise while being comprehensive. The only minor note is that 'comprehensive testing strategies' is slightly buzzwordy, but the rest of the description more than compensates with concrete specifics.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions and tools: Jest, Vitest, Testing Library, unit tests, integration tests, end-to-end testing, mocking, fixtures, and test-driven development. These are all concrete, actionable capabilities. | 3 / 3 |
Completeness | Clearly answers both 'what' (implement testing strategies using specific tools for specific test types) and 'when' (explicit 'Use when writing JavaScript/TypeScript tests, setting up test infrastructure, or implementing TDD/BDD workflows'). | 3 / 3 |
Trigger Term Quality | Includes strong natural keywords users would say: 'Jest', 'Vitest', 'Testing Library', 'unit tests', 'integration tests', 'end-to-end testing', 'mocking', 'fixtures', 'TDD', 'BDD', 'JavaScript/TypeScript tests', 'test infrastructure'. Good coverage of common variations. | 3 / 3 |
Distinctiveness Conflict Risk | Clearly scoped to JavaScript/TypeScript testing with specific frameworks (Jest, Vitest, Testing Library). The combination of specific tools and testing methodologies creates a distinct niche unlikely to conflict with other skills. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
42%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This skill is a comprehensive but extremely verbose testing reference that dumps every common testing pattern into a single file. While the code examples are high-quality and executable, the content largely teaches Claude things it already knows (basic unit testing, CRUD tests, calculator functions). The lack of progressive disclosure and the sheer volume of boilerplate examples make this a poor use of context window budget.
Suggestions
Reduce content by 70%+ by removing trivial examples (calculator, counter hook, basic CRUD) and focusing only on non-obvious patterns, project-specific conventions, or tricky edge cases Claude wouldn't know.
Split into multiple files: SKILL.md as a concise overview with references to MOCKING.md, INTEGRATION.md, FRONTEND.md, etc.
Add a decision workflow: when to use Jest vs Vitest, when to use mocks vs DI vs spies, and a TDD step-by-step sequence with validation checkpoints.
Remove the 15-item best practices list — Claude already knows AAA pattern, test isolation, and edge case testing. Replace with project-specific conventions or non-obvious guidelines only.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | Extremely verbose at ~600+ lines. Includes trivial examples Claude already knows (calculator add/divide, counter hooks, basic CRUD tests). Many patterns are textbook examples that don't add novel value. The 15-item best practices list restates common knowledge. Massive token cost for information Claude can generate from its training. | 1 / 3 |
Actionability | All code examples are fully executable TypeScript with complete implementations and corresponding test files. Config files are copy-paste ready, and patterns include both source code and test code side by side. | 3 / 3 |
Workflow Clarity | Patterns are presented clearly with good describe/it structure, and setup/teardown is shown. However, there's no clear workflow for when to apply which pattern, no decision tree for choosing between Jest and Vitest, and no TDD workflow sequence despite being mentioned in the description. The skill reads as a reference catalog rather than a guided workflow. | 2 / 3 |
Progressive Disclosure | Monolithic wall of content with no references to external files. Everything is inline in a single massive document. Content like integration testing patterns, frontend testing, and mocking patterns could easily be split into separate referenced files. No bundle files exist to support progressive disclosure. | 1 / 3 |
Total | 7 / 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 |
|---|---|---|
skill_md_line_count | SKILL.md is long (1022 lines); consider splitting into references/ and linking | Warning |
Total | 10 / 11 Passed | |
- Repository
- Dicklesworthstone/pi_agent_rust
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