Folder src : all ts code

Folder dist : non ts code

Install typescript globally : sudo npm i -g typescript

Check install : tsc -v

Create tsconfig.json : tsc --init

In tsconfig.json (already up) :

1. "target": "es6",
2. "rootDir": "./src",
3. "outDir": "./dist",
4. "removeComments": true,

Compile one typescript file to javascript : tsc index.ts

Compile all typescript files to javascript : tsc

Watch errors but don't compile : tsc --watch index.ts