Sing-Kai/typeScript-node-tutorial

Tutorial On Setting Up And Configuring TypeScript in Node

Simple tutorial on how to set up and configure Typescript in Node

Prerequistes

Basic understaind of Node.js and TypeScript

Installing TypeScript

Create and initialise a Node.js project with package.json

npm init

Install TypeScript with below command:

npm install typescript --save-dev

Check the version you have using below:

npx tsc --version

It's advisable to install TypeScript as a project-specific dependency. The same version of the language will then be used, regardless of the machine running the code.

Global installation can be done with below command:

npm install typescript --global

version check

tsc --version

Install tsconfig.json

use the below commandline to install and create a tsconfig.json file

npx tsconfig.json

Complie TypeScript to JavaScript

Use the below command

npx tsc

Folder and File Structure

At the moment there is nothing to compile so lets create something to allow for this.

Create a src at the root directory, inside src create a main.ts folder

In main.ts add the following lines

const sayHello = (name: string):void => {
  console.log(`Hello ${name}`)
}
 
sayHello("TypeScript");

if you look at the tsconfig.json file you'll see a this configuration

"outDir": "./dist"

This is where the compile js files will created, there fore we need to create a dist folder

You should end up with a structure looking like this

├── dist
│   └── main.js
├── package.json
├── package-lock.json
├── src
│   └── main.ts
└── tsconfig.json

NOTE if you are pushing this into gitHub don't forget to add the .gitignore file with node_modules and dist folder to be ignored

How to Execute TypeScript Files

Install ts-node with the below command line

npm install ts-node --save-dev

Using ts-node will compile TypeScript and run the JavaScript code

use the below command line now to execute TypeScript file:

npx ts-node src/main.ts

Terminal should output

Hello TypeScript

TLDR

Command	What it does
npm install typescript --save-dev	Install TypeScript as dependency
npm install typescript --global	Install TypeScript as globally
npx tsconfig.json	create tsconfig.json file
npx tsc	compiles TypeScript files
npm install ts-node --save-dev	package that compiles ts files and runs js files
npx ts-node src/main.ts	excute ts files with ts-node

Commands for quick setup:

npm init -y

npm install typescript ts-node --save-dev

npx tsconfig.json select node.js

mkdir src dist