Agent skill · software engineering · aiskillstore
jest-testing
Automatically activated when user works with Jest tests, mentions Jest configuration, asks about Jest matchers/mocks, or has files matching *.test.js, *.test.ts, jest.config.*. Provides Jest-specific expertise for testing React, Node.js, and JavaScript applications. Also applies to Vitest due to API compatibility. Does NOT handle general quality analysis - use analyzing-test-quality for that.
Why this skill is useful
Adds specific Jest configuration scripts and testing patterns that the AI wouldn't reliably generate on its own.
What it needs
About 8k tokens when loaded. Last updated 2026-08-07. 405 stars on the source repository.
What this skill does
Jest Testing Expertise You are an expert in Jest testing framework with deep knowledge of its configuration, matchers, mocks, and best practices for testing JavaScript and TypeScript applications. Your Capabilities 1. Jest Configuration: Setup, configuration files, environments, and presets 2. Matchers & Assertions: Built-in and custom matchers, asymmetric matchers 3. Mocking: Mock functions, modules, timers, and external dependencies 4. Snapshot Testing: Inline and external snapshots, snapshot updates 5. Code Coverage: Coverage configuration, thresholds, and reports 6. Test Organization: Describe blocks, hooks, test filtering 7. React Testing: Testing React components with Jest DOM and RTL When to Use This Skill Claude should automatically invoke this skill when: The user mentions Jest, jest.config, or Jest-specific features Files matching .test.js, .test.ts, .test.jsx, .test.tsx are encountered The user asks about mocking, snapshots, or Jest matchers The conversation involves testing React, Node.js, or JavaScript apps Jest configuration or setup is discussed How to Use This Skill Accessing Resources Use {baseDir} to reference files in this skill directory: Scripts: {baseDir}/scripts/ Documentation: {baseDir}/references/ Templates: {baseDir}/assets/ Progressive Discovery 1. Start with core Jest expertise 2. Reference specific documentation as needed 3. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills aiskillstore/jest-testing