Note + TypeScript + Jest = Testing

pasos-node-ts-jest.md

Pasos para configurar Jest con TypeScript, en Node

Documentación oficial sobre Jest

1. Instalaciones de desarrollo (super test es útil para probar Express)

npm install -D jest @types/jest ts-jest supertest

2. Crear archivo de configuración de Jest

npx create-jest

3. En el archivo jest.config.js configurar

preset: 'ts-jest',
testEnvironment: "jest-environment-node",

// Opcional - The paths to modules that run some code to configure or set up the testing environment before each test
// setupFiles: ['dotenv/config'],

4. Crear scripts en el package.json

"test": "jest",
"test:watch": "jest --watch",
"test:coverage": "jest --coverage",

Pongo mi configuracion por si alguno esta usando "type": "module", Dentro del package.json

{
  "name": "02-bases",
  "version": "0.0.1",
  "description": "Esta es mi primera aplicacion real de node",
  "license": "ISC",
  "author": "\"Nico\"",
  "type": "module",
  "main": "app.js",
  "scripts": {
    "dev": "tsx watch src/app.ts",
    "build": "rimraf ./dist && tsc",
    "start": "npm run build && node dist/app.js",
    "test": "node --experimental-vm-modules node_modules/jest/bin/jest.js",
    "test:watch": "node --experimental-vm-modules node_modules/jest/bin/jest.js --watch",
    "test:coverage": "node --experimental-vm-modules node_modules/jest/bin/jest.js --coverage"
  },
  "devDependencies": {
    "@types/jest": "^30.0.0",
    "@types/mocha": "^10.0.10",
    "@types/node": "^25.0.3",
    "jest": "^30.2.0",
    "nodemon": "^3.1.11",
    "rimraf": "^6.1.2",
    "supertest": "^7.1.4",
    "ts-jest": "^29.4.6",
    "ts-node": "^10.9.2",
    "tsx": "^4.21.0",
    "typescript": "^5.9.3"
  },
  "dependencies": {
    "axios": "^1.13.2",
    "chalk": "^5.6.2",
    "get-age": "^1.0.1",
    "inquirer": "^13.1.0",
    "uuid": "^13.0.0",
    "winston": "^3.19.0"
  }
}

Agregar esto antes de compiler options en ts.config para evitar ver error Jest fuera de rootdic