jest-generator
Generate Jest unit tests for JavaScript/TypeScript with mocking, coverage. Use for JS/TS modules, React components, test generation, or encountering missing coverage, improper mocking, test structure errors.
Install with Tessl CLI
npx tessl i github:secondsky/claude-skills --skill jest-generator88
Does it follow best practices?
If you maintain this skill, you can automatically optimize it using the tessl CLI to improve its score:
npx tessl skill review --optimize ./path/to/skillValidation for skill structure
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 well-crafted skill description that excels across all dimensions. It provides specific capabilities (Jest tests, mocking, coverage), includes natural trigger terms developers would use, explicitly states both what it does and when to use it, and carves out a distinct niche in the JavaScript/TypeScript testing space.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: 'Generate Jest unit tests', 'mocking', 'coverage' for 'JavaScript/TypeScript', 'JS/TS modules', 'React components'. These are concrete, actionable capabilities. | 3 / 3 |
Completeness | Clearly answers both what ('Generate Jest unit tests for JavaScript/TypeScript with mocking, coverage') and when ('Use for JS/TS modules, React components, test generation, or encountering missing coverage, improper mocking, test structure errors'). | 3 / 3 |
Trigger Term Quality | Excellent coverage of natural terms users would say: 'Jest', 'unit tests', 'JavaScript', 'TypeScript', 'JS/TS', 'React components', 'test generation', 'coverage', 'mocking'. These are all terms developers naturally use. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive with clear niche: Jest-specific testing for JS/TS ecosystem. The combination of 'Jest', 'JavaScript/TypeScript', 'React components', and specific error types like 'improper mocking' creates a clear, non-conflicting scope. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
79%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, actionable Jest testing skill with excellent code examples and good organization. The main weaknesses are the lack of an explicit test generation workflow with validation steps, and the monolithic structure that could benefit from splitting advanced topics into separate files for better progressive disclosure.
Suggestions
Add an explicit workflow section: 1. Analyze source file → 2. Identify test cases → 3. Write tests → 4. Run tests → 5. Check coverage meets threshold → 6. Fix gaps if needed
Consider splitting React component testing and advanced mocking patterns into separate reference files (e.g., REACT_TESTING.md, MOCKING.md) with clear links from the main skill
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The content is lean and efficient, providing only necessary information without explaining basic concepts Claude already knows. Every section serves a clear purpose with no padding or unnecessary context. | 3 / 3 |
Actionability | Provides fully executable, copy-paste ready code examples for all major patterns including mocking, async testing, timers, and React components. The bash commands and TypeScript examples are complete and immediately usable. | 3 / 3 |
Workflow Clarity | While the test structure and patterns are clear, there's no explicit workflow for generating tests (e.g., analyze source → identify test cases → write tests → validate coverage). The quality checklist exists but isn't integrated into a step-by-step process with validation checkpoints. | 2 / 3 |
Progressive Disclosure | Content is well-organized with clear sections, but everything is inline in one file. For a skill of this length (~150 lines), advanced patterns like React testing or complex mocking could be split into separate reference files with clear navigation. | 2 / 3 |
Total | 10 / 12 Passed |
Validation
75%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 12 / 16 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
description_trigger_hint | Description may be missing an explicit 'when to use' trigger hint (e.g., 'Use when...') | Warning |
allowed_tools_field | 'allowed-tools' contains unusual tool name(s) | Warning |
metadata_version | 'metadata' field is not a dictionary | Warning |
license_field | 'license' field is missing | Warning |
Total | 12 / 16 Passed | |
- Reviewed
Table of Contents
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