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

describe('Calculator', () => {
  let calc;
  beforeEach(() => { calc = new Calculator(); });

  test('adds two numbers', () => {
    expect(calc.add(2, 3)).toBe(5);
  });