Step-by-Step: Setting up a Node.js (Express) Server in TypeScript

Step by step, oh, baby, gonna get to you, girl!

TypeScript is really gaining traction these days and although most node.js server code is written in JavaScript, TypeScript is finally invading into this territory too.

Recently, i wrote a new node.js server and decided to write it in TypeScript. I referenced several articles and thought of sharing the exact steps that can help someone to quickly setup a node.js server in TypeScript. So, here we go…

1. Have a working node.js server in JavaScript (with express, express-session etc. packages already installed). For this article, let’s assume that the server code is in ‘./src’ directory and the output directory is ‘./dist’.

2. Install the following packages:

$ npm i typescript ts-node-dev — save-dev

3. Install the following types so that TypeScript knows about these:

$ npm i @types/express @types/express-session @types/node @types/request — save-dev

4. Initialize typescript config file (tsconfig.json):

$ npx tsc — init

This will create tsconfig.json file. Update the compiler options in the file as desired.

5. Optional step: add linting support:

$ npm i tslint — save-dev

6. Add the following scripts in package.json:

“tsc”: “tsc”,

“dev”: “ts-node-dev — respawn — transpileOnly ./src/index.ts”,

“prod”: “tsc && node ./dist/index.js”,

7. To run the server in watch mode in development environment, run the following command:

$ npm run dev

8. Similarly, to run the server in production environment, run the following command:

$ npm run prod

Sample Configuration

tsconfig.json

package.json

I hope this helps someone. Happy coding :)