express-http-error-handler

express-http-error-handler is a package for handling HTTP errors in Express applications in a simple and efficient way. It provides specific error classes for the most common HTTP status codes.

Installation

To install the package, use npm:

npm install express-http-error-handler

Error List

Here are the available error classes in the package:

| Error Class | HTTP Status Code | Description | |------------------------|------------------|----------------------------------------------| | NotFoundError | 404 | Represents a 404 Not Found error | | BadRequestError | 400 | Represents a 400 Bad Request error | | InternalServerError | 500 | Represents a 500 Internal Server Error | | UnauthorizedError | 401 | Represents a 401 Unauthorized error | | ForbiddenError | 403 | Represents a 403 Forbidden error |

Usage

NotFoundError

userService.ts

In this example, we are trying to fetch a user by their ID. If the user does not exist in the database, a NotFoundError is thrown.

    import { NotFoundError} from 'express-http-error-handler';

    async getUserById(id: string){
        const user = await this.prismaService.user.findUnique({ where: { id } });
        if (!user) throw new NotFoundError(`User not found with id ${id}`);
        return user;
    }

userController.ts

In the controller, we handle the request by catching the error and returning a proper HTTP response.

    import { Request, Response } from 'express';
    import {HttpError} from 'express-http-error-handler'

    async getUserById(req : Request, res : Response){
        try{
            const {id} = req.params;
            const user = await this.userService.getUserById(id);
            return res.status(200).json(user);
        }catch(error : any){
            return error instanceof HttpError
            ? res.status(error.statusCode).json(error)
            : res.status(500).json(error);
        }
    }

Response

BadRequestError

userService.ts

This example checks if the email is provided when creating a new user. If it's missing, a BadRequestError is thrown.

    import { BadRequestError } from 'express-http-error-handler';

    async createUser(data: any){
        if (!data.email) throw new BadRequestError('Email is required');
        return await this.prismaService.user.create({ data });
    }

userController.ts

In the controller, we handle the request by catching the error and returning a proper HTTP response.

    import { Request, Response } from 'express';
    import {HttpError} from 'express-http-error-handler'

    async createUserController(req: Request, res: Response) {
        try {
            const user = await this.userService.createUser(req.body);
            return res.status(201).json(user);
        } catch (error: any) {
            return error instanceof HttpError
                ? res.status(error.statusCode).json(error)
                : res.status(500).json(error);
        }
    }

Response

InternalServerError

paymentService.ts

In this example, we are processing a payment. If something goes wrong during the payment process, an InternalServerError is thrown.

    import { InternalServerError } from 'express-http-error-handler';

    async processPaymentService(paymentData: any){
    try {
        // Process payment logic
        } catch (err) {
            throw new InternalServerError('Payment processing failed');
        }
    }

paymentController.ts

    import { Request, Response } from 'express';
    import {HttpError} from 'express-http-error-handler'

    async processPaymentController(req: Request, res: Response) {
        try {
            await this.paymentService.processPaymentService(req.body);
            return res.status(200).json({ message: 'Payment successful' });
        } catch (error: any) {
            return error instanceof HttpError
                ? res.status(error.statusCode).json(error)
                : res.status(500).json(error);
        }
    }

Response

UnauthorizedError

authService.ts

Here, we validate the user's authentication token. If the token is invalid, an UnauthorizedError is thrown.

    import { UnauthorizedError } from 'express-http-error-handler';

    async getUserProfileService(token: string){
        const user = await this.authService.validateToken(token);
        if (!user) throw new UnauthorizedError('Invalid token');
        return user;
    }

authController

In the controller, we handle the request by catching the error and returning a proper HTTP response.

    import { Request, Response } from 'express';
    import {HttpError} from 'express-http-error-handler'

    async getUserProfileController(req: Request, res: Response) {
        try {
            const user = await this.authService.getUserProfileService(req.headers.authorization);
            return res.status(200).json(user);
        } catch (error: any) {
            return error instanceof HttpError
                ? res.status(error.statusCode).json(error)
                : res.status(500).json(error);
        }
    }

Response

ForbiddenError

adminService.ts

In this example, we are verifying if the user has the role of 'admin' before granting access to the admin panel. If the user is not an admin, a ForbiddenError is thrown.

    import { ForbiddenError } from 'express-http-error-handler';

    async accessAdminPanel(user: User){
        if (user.role !== 'admin') throw new ForbiddenError('Access denied: Admins only');
    }

adminController.ts

In the controller, we handle the request by catching the error and returning a proper HTTP response.

    import { Request, Response } from 'express';
    import {HttpError} from 'express-http-error-handler'

    async accessAdminPanelController(req: Request, res: Response) {
        try {
            await this.adminService.accessAdminPanelService(req.user);
            return res.status(200).json({ message: 'Welcome to the admin panel' });
        } catch (error: any) {
            return error instanceof HttpError
                ? res.status(error.statusCode).json(error)
                : res.status(500).json(error);
        }
    }   

Response