Global Error Handler

PORT="3000"
NODE_ENV="development"
LOG_LEVEL="info"

interface Config {
  PORT: number;
  NODE_ENV: string;
  LOG_LEVEL: string;
}
 
const env: Config = {
  PORT: Number(process.env.PORT) || 3000,
  NODE_ENV: process.env.NODE_ENV || "development",
  LOG_LEVEL: process.env.LOG_LEVEL || "info"
};
 
export default env;

import { Request, Response, NextFunction } from "express";
import env from "../configs/env";
 
import { ApiError } from "../utils/api-error";
import { logger } from "../utils/logger";
import { STATUS_CODES } from "../constants/status-codes";
 
export const errorHandler = (
  err: Error,
  req: Request,
  res: Response,
  next: NextFunction
) => {
  let statusCode = 500;
  let message = "Internal server error";
 
  if (err instanceof ApiError) {
    statusCode = err.statusCode;
    message = err.message;
  }
 
  logger.error(
    err,
    `Error: ${message} | Status: ${statusCode} | Path: ${req.method} ${req.originalUrl}`
  );
 
  const response = {
    success: false,
    message,
    ...(env.NODE_ENV === "development" && { stack: err.stack })
  };
 
  res.status(statusCode).json(response);
};

import express, { type Application } from "express";
import dotenv from "dotenv-flow";
dotenv.config();
import { errorHandler } from "./middlewares/error-handler";
 
const app: Application = express();
 
app.use(express.json());
 
// routes here
// ....
 
// Global error handler (should be after routes)
app.use(errorHandler);
 
export default app;