Centralized error handler - Express application

error_handler.ts

import logger from './logger';

export class AppError extends Error {
    statusCode: number;
    message: string;

    constructor(statusCode, message) {
        super(message);
        this.statusCode = statusCode;
        this.message = message;
    }
}

const handleKnownExceptions = (err, res) => {
    logger.error(err);
    const { statusCode, message } = err;
    res.status(statusCode).json({error: {message});
};

const handleUnknownExceptions = (err, res) => {
    logger.error(err);
    res.status(500).json({ error: {message: 'Something went wrong.' }});
};

export const handleError = (err, res) => {
    err instanceof AppError ? handleKnownExceptions(err, res) : handleUnknownExceptions(err, res);
};