jest-skill
Generates Jest unit and integration tests in JavaScript or TypeScript. Covers mocking, snapshots, async testing, and React component testing. Use when user mentions "Jest", "describe/it/expect", "jest.mock", "toMatchSnapshot". Triggers on: "Jest", "expect().toBe()", "jest.mock",...
Profile →npx skills add sickn33/agentic-awesome-skills --skill jest-skill --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# Jest Testing Skill ## When to Use Use this skill when you need generates Jest unit and integration tests in JavaScript or TypeScript. Covers mocking, snapshots, async testing, and React component testing. Use when user mentions "Jest", "describe/it/expect", "jest.mock", "toMatchSnapshot". Triggers on: "Jest", "expect().toBe()", "jest.mock",... ## Core Patterns ### Basic Test ```javascript describe('Calculator', () => { let calc; beforeEach(() => { calc = new Calculator(); }); test('adds two numbers', () => { expect(calc.add(2, 3)).toBe(5); }); test('throws on division by zero', () => { expect(() => calc.divide(10, 0)).toThrow('Division by zero'); }); }); ``` ### Matchers ```javascript expect(value).toBe(exact); // === strict expect(value).toEqual(object); // deep equality expect(value).toBeTruthy(); expect(value).toBeNull(); expect(value).toBeGreaterThan(3); expect(value).toBeCloseTo(0.3, 5); expect(str).toMatch(/regex/); expect(arr).toContain(item); expect(arr).toHaveLength(3); expect(obj).toHaveProperty('name'); expect(obj).toMatchObject({ name: 'Alice' }); expect(() => fn()).toThrow(CustomError); ``` ### Mocking ```javascript // Mock function const mockFn = jest.fn(); mockFn.m
- When to Use
- Core Patterns
- Basic Test
- Matchers
- Mocking
- Async Testing
- React Component Testing (Testing Library)
- Snapshot Testing
- Anti-Patterns
- Quick Reference
- Deep Patterns
- Limitations
What does the jest-skill skill do?
Generates Jest unit and integration tests in JavaScript or TypeScript. Covers mocking, snapshots, async testing, and React component testing. Use when user mentions "Jest", "describe/it/expect", "jest.mock", "toMatchSnapshot". Triggers on: "Jest", "expect().toBe()", "jest.mock",...
How do I install it?
Run `npx skills add sickn33/agentic-awesome-skills --skill jest-skill --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From sickn33/agentic-awesome-skills, a repository with 44,414 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.