TypeScript with NodeJS

TypeScript has had first class support for NodeJS since inception. Here's how to setup a quick NodeJS project:

Note: many of these steps are actually just common practice nodejs setup steps

1. Setup a nodejs 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 (node ./node_modules/typescript/lib/tsc --init)

That's it! Fire up your IDE (e.g. alm -o) and play around. Now you can use all the built in node modules (e.g. import fs = require('fs')) with all the safety and developer ergonomics of TypeScript!

Bonus: Live compile + run

• 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 rereuns 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.

Creating TypeScript node modules

You can even use other node modules written in TypeScript. As a module author, one real thing you should do:

• you might want to have a typings field (e.g. src/index) in your package.json similar to the main field to point to the default TypeScript definition export. For an example look at package.json for csx.

Example package: npm install csx for csx, usage: import csx = require('csx').

Bonus points

Such NPM modules work just fine with browserify (using tsify) or webpack (using ts-loader).