typescript-must-know

Setup

Setup is from https://basarat.gitbooks.io/

1. Setup a Node.js project package.json. Quick one : npm init -y

2. Add TypeScript (npm install typescript --save-dev)

3. Add node.d.ts (npm install @types/node --save-dev)

4. Init a tsconfig.json for TypeScript options (npx tsc --init)

5. Make sure you have compilerOptions.module:commonjs in your tsconfig.json

Bonus: Live compile + run

Live compile part is from https://basarat.gitbooks.io/

• Add ts-node which we will use for live compile + run in node (npm install ts-node --save-dev)
• Add nodemon which will invoke ts-node whenever a file is changed (npm install nodemon --save-dev)

Now just add a script target to your package.json based on your application entry e.g. assuming its index.ts:

  "scripts": {
    "start": "npm run build:live",
    "build:live": "nodemon --exec ./node_modules/.bin/ts-node -- ./index.ts"
  },

So you can now run npm start and as you edit index.ts:

• nodemon reruns its command (ts-node)
• ts-node transpiles automatically picking up tsconfig.json and the installed typescript version,
• ts-node runs the output javascript through Node.js.

Build JS file

$ npm run build

Reference

• https://basarat.gitbooks.io/typescript/docs/quick/nodejs.html