ts-jest का Setup

// npm install --save-dev jest ts-jest @types/jest
console.log("jest, ts-jest, and @types/jest are needed as dev dependencies");

// jest.config.js
// module.exports = { transform: { "^.+\\.tsx?$": "ts-jest" } };
console.log("transform maps .ts/.tsx files through ts-jest before running");

// jest.config.js
// globals: { "ts-jest": { isolatedModules: true } }
console.log("Test compiler options can relax settings for faster runs");

// Component.ts
// Component.test.ts   (or __tests__/Component.test.ts)
console.log("Jest auto-discovers *.test.ts files or __tests__ folders");

// npm test          (runs jest)
// npx tsc --noEmit  (full-project type check ts-jest's transform may miss)
console.log("Run both jest and tsc --noEmit for full coverage");