NodeJS typescript simple auto-reload on file change

First install ts-node-dev:

npm i --save-dev ts-node-dev

Then add

"start": "./node_modules/.bin/tsnd --respawn app.ts"

to package.json in the scripts section, example:

{
  "name": "myapp-backend",
  "version": "1.0.0",
  "description": "To make it easy for you to get started with GitLab, here's a list of recommended next steps.",
  "main": "index.js",
  "scripts": {
    "build": "./node_modules/.bin/tsc -b tsconfig.json",
    "start": "./node_modules/.bin/tsnd --respawn app.ts"
  }
  /* ... */
}