Local setup

npm init -y
 
npm install --save-dev jest ts-jest typescript @types/jest


npx tsc --init
npx ts-jest config:init

  "type": "module",
  "scripts": {
    "test:unit": "jest",
    "start": "tsx watch src/index.ts"
  },
    
    
   ts.config.json
{
  "compilerOptions": {
    "module": "ESNext",
    "moduleResolution": "Node",
    "target": "ESNext",
    "outDir": "dist",
    "rootDir": "src",
    "esModuleInterop": true,
    "strict": true,
    "resolveJsonModule": true
  },
  "include": ["src/**/*"]
}