How to set up a Node Project With Typescript

Node.js is an open-source JavaScript runtime environment for building server(backend) applications. To add type checking something that is not present in plain JavaScript we use Typescript. Typescript makes our code more secure and robust. Mainly it will help us to reduce bugs in our code. Here i'll give you the step by step instructions to setup your next Node.js project with Typescript.

Initializing Our Project

Create a new directory with the project name that you wan't to create. After that run below command which will walks you through an interactive session to create a package.json file.

for yarn

yarn init

for npm

npm init

Installing Dependencies

Install the typescript package as a development dependency using below command.

for yarn

yarn add -D typescript

for npm

npm i -D typescript

Now install express and it's type definitions with the below commands.

for yarn

yarn add express && yarn add -D @types/express

for npm

npm i express && npm i -D @types/express

Additionally i'm using nodemon which will help us by automatically restarting our server when we make changes to our files. For nodemon to work with typescript we need another dependency called ts-node. To install both run the below command.

for yarn

yarn add -D nodemon ts-node

for npm

npm i -D nodemon ts-node

Configuring Typescript Compiler

Now that we have all our dependencies we can do our typescript configuration. To do so run the below command.

for yarn

yarn tsc --init

for npm

npx tsc --init

This will create a tsconfig.json file in which we can see lots of configuration options, but dont worry about them too much, we only need to change a few things you can simply leave rest of them as they are.

Output Directory

This will be the folder in which our compiled code will get saved. Create a dist folder in the project root directory and find the outDir line in tsconfig.json file. Uncomment it and change it to

"outDir": "./dist"

Files for compilation

By default the compiler include all files in our project. To include files inside *src * folder only make below changes to our configuration.

{  "compilerOptions": {    ...  },  "include": ["src"]}

Final Touches

We are almost ready with the setup. Create a folder src in project root directory and create an index.ts file inside. This will be the starting point of our application. Add below boilerplate code to index.ts

import express from "express";const app = express();const port = 3000;app.get("/", (req, res) => {  res.send("Hello World!");});app.listen(port, () => {  console.log(`Example app listening on port ${port}`);});

Now we can create a script in package.json to run our server with nodemon. For that modify your package.json file like this.

{  ...  "scripts": {    "dev": "nodemon src/index.ts"  },  ...}

now run our app with the following command

for yarn

yarn run dev

for npm

npx run dev

Congratulations! you've successfully set up your Node.js project with Typescript!

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