Why should we use Typescript with NodeJs and Express?

Here are some topics I can cover to explain why using Typescript with Node and Express is beneficial :

1. What is Typescript and why is it useful in web development?

2. Why You Should Choose Typescript Over JavaScript?

3. How to set up TypeScript with Node.js and Express.

4. Best practices for using TypeScript with Node.js and Express.

1. What is Typescript?

• Typescript is a programming language that adds static typing, compiling and OOP to JavaScript. It can be used for both client-side (Front-end Frameworks like Angular, React and vue) and server-side applications (Nodejs).

Why is it useful in web development?

• It makes our code more secure and robust by preventing many bugs before the code is even shipped.

• It catches problems during code development and integrates wonderfully with code editors like Visual Studio Code.

2. Why You Should Choose Typescript Over JavaScript?

Three reasons why you should choose TypeScript over JavaScript

• Typescript is an enhanced version of JavaScript.
• TypeScript makes it easier to write accurate code more quickly and catch bugs prior to runtime.
• TypeScript is more reliable and easier to refactor. This enables developers to avoid errors and do restructure much easier.
• TypeScript is more explicit. It takes our attention to make types explicitly on variables, return type and etc...
• TypeScript is an object-oriented scripting language. These features make it possible for developers to write more structured, maintainable, and scalable code.
• Dependent language (compiles to JavaScript).

3. How to set up TypeScript with Node.js and Express.

Steps to setup Nodejs typescript project :

1. Install Node and npm :

Make sure that you installed Node on your device

node -v to detect whether you have installed the Node or not. If you installed node output is v18.15.0 or any version. If you didn't install node output will be node: command not found.

You need to install node by going to Nodejs website NodeJS website

Make sure that you installed Node Package Manager npm on your device npm -v to detect whether you have installed the npm or not. If you installed npm output is 9.6.1 or any version. If you didn't install npm output will be npm: command not found.

2. Create a New Project Folder.

3. Start running npm in your project folder :

• Open a terminal.
• Run the command npm init -y to initial npm and install packages.

4. Add TypeScript as a dev dependency

npm install typescript --save-dev

5. Install ambient Node.js types for TypeScript :

npm install @types/node --save-dev

6. Create tsconfig.json :

npx tsc --init

• Copy this in tsconfig.json

{
  "compilerOptions": {
    "target": "es5",                          
    "module": "commonjs",                    
    "lib": ["es6"],                     
    "allowJs": true,
    "outDir": "dist",                          
    "rootDir": ".",
    "strict": true,         
    "noImplicitAny": true,
    "esModuleInterop": true,
    "resolveJsonModule": true
  }
}

7. To reload server :

npm install nodemon ts-node -D

• nodemon which is used to watch for changes to our code and automatically restart when a file is changed.

• ts-node for running TypeScript code directly without having to wait for it be compiled.

• Add nodemon.json file and write the following in it:
  

{
    "watch": ["./"],
    "ext": ".ts,.js",
    "ignore": [],
    "exec": "npx ts-node index.ts"
  }

8. Write in scripts in package.json, to use it in running server :

  "scripts": {
    "start:dev": "npx nodemon"
  },

9. Create our first TypeScript file index.ts.

10. Create simple server using express framework

• First install express and @types/express

npm i express
npm i @types/express -D

• Write in index.ts

import express,{ Application, Router ,Request, Response} from "express";

const app :Application = express();
var router :Router= require('express').Router();
const port :number = 3000;
app.use(router);

router.get("/", function (req:Request, res:Response) : void {
    res.send("<h1>Hello, I'm Ali Ahmed. I'm Software Engineer</h1>");
  });
app.listen(port, () => {
    console.log(`Server Running here 👉 http://localhost:${port}`);
})

11. Finally run this command to run server

npm run start:dev 

Output will be :

> testnodewithtypescript@1.0.0 start:dev
> npx nodemon

[nodemon] 2.0.22
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): **/*
[nodemon] watching extensions: ts,js
[nodemon] starting `npx ts-node index.ts`
Server Running here 👉 http://localhost:3000

4. Best practices for using TypeScript with Node.js and Express.

1. Use strict typing:

{
  "compilerOptions": {
    "strict": true
  }
}

• One of the key advantages of TypeScript is that it provides strong typing.
• Strict mode activates 2 main compiler options:
  1. noImplicitAny : explicit anys are not accepted by TypeScript.
  2. strictNullChecks : will ask to tell when a value can be null.

2. Use interfaces:

• Interfaces are a powerful feature of TypeScript that allow you to define a contract for an object's properties and methods. This can help you catch errors at compile-time and make your code more organized and maintainable. Use interfaces to define the shape of your data models and API responses. By using an interface to define the shape of the user object, you can catch errors at compile-time if you try to assign the wrong type of data to a property, or if you forget to include a required property. This can help you write more reliable code and avoid common bugs.

// In API responses
import { Request, Response } from 'express';

interface User {
    id: number;
    name: string;
    email: string;
    socialMediaProfile:string[]
    createdAt: Date;
  }

function getUser(req: Request, res: Response): void {
    const user: User = {
        id: 1,
        name: 'Ali Ahmed',
        email: '[e-mail]',
        socialMediaProfile:[
            "linkedin.com/in/ali-ahmed-fathi", // linkedin profile
            "https://github.com/AliFathy-1999", //Github profile
        ],
        createdAt: new Date(),
      };
}

//In Data models:

interface IUserModel{
    fname:String,
    lname:String,
    email:String,
    password:String,
}
const schema= new Schema<IUserModel>({
    fname:{
        type:String,
        required:true,
        trim:true,
        minlength:3,
        maxlength:20
    },
    lname:{
        type:String,
        required:true,
        trim:true,
        minlength:3,
        maxlength:20
    },
    email:{
        type:String,
        required:true,
        unique:true,
    },
    password:{
        type:String,
        required:true,
        trim:true,
        minlength:6,
    },
},{
    timestamps:true  //createdAt, updatedAt
});

3. Use Generics:

It helps developers to write more reusable and flexible code. Use generics to write functions and classes that can work with different types of data.

/*
Let's say you have a function that takes an array of objects and returns an array of a specific property from each object. You can use generics to make this function work with any type of object and any type of property.
*/
  function myGeneric<T, K extends keyof T>(items: T[], key: K): T[K][] {
    return items.map(item => item[key]);
  }
  const users: User[] = [
    { id: 1, name: 'Mustafa Mahmoud',socialMediaProfile:["",""], email: '[e-mail]',createdAt:new Date },
    { id: 2, name: 'Bassem Mahmoud',socialMediaProfile:["",""], email: '[e-mail]',createdAt:new Date },
  ];

  const names = myGeneric(users, 'name'); // ['Mustafa Mahmoud', 'Bassem Mahmoud']

4. Use Async/Await:

• API endpoint that fetches some data from a database using an asynchronous function.

  const getUserByEmail = async (req: Request, res: Response): Promise<void> =>{
    try {
        const { body: { email } } = req
      const data = await User.findOne({email});
      res.json(data);
    } catch (err) {
      res.status(500).json({ error: 'Internal server error' });
    }
  }

Finally, I want to thank you for taking the time to read my article and I hope this article is useful for you :).

Comments

[Levi alkali damat]

thanks for this article