ExpressUmer Documentation

About

Expressumer is a custom error handling middleware for Express.js applications, designed to handle errors gracefully and provide meaningful error messages in your API responses.

Getting Started

Install expressumer as an npm module :

npm install expressumer

Usage Instructions

Set Up Your Express Application:

In your Express application, you need to import Expressumer and set it up as middleware. Here’s a basic example:

const express = require('express');
const { errorHandler, ErrorResponse, ValidationError, NotFoundError } = require('expressumer');
const app = express();
// Sample route that throws a custom error
app.get('/custom-error', (req, res, next) => {
  return next(new ErrorResponse('This is a custom error message', 400));
});
// Sample route that throws a validation error
app.get('/validation-error', (req, res, next) => {
  return next(new ValidationError('Validation error occurred'));
});
// Sample route that throws a not found error
app.get('/not-found', (req, res, next) => {
  return next(new NotFoundError('Resource not found'));
});
// Use the custom error handler
app.use(errorHandler);
const PORT = process.env.PORT || 5000;
app.listen(PORT, () => console.log(`Server running on port ${PORT}`));

API Reference

ErrorResponse

new ErrorResponse(message: string, statusCode: number)

message : A descriptive error message . statusCode : HTTP status code (e.g., 400 for Bad Request).

Example

const { ErrorResponse } = require('expressumer');
throw new ErrorResponse('Invalid input data', 400);

ValidationError

new ValidationError(message: string)

message : A descriptive validation error message.

Example

const { ValidationError } = require('expressumer');
throw new ValidationError('Validation failed');

NotFoundError

new NotFoundError(message: string)

message : A descriptive message indicating that a resource was not found.

Example

const { NotFoundError } = require('expressumer');
throw new NotFoundError('The requested resource does not exist');

errorHandler

app.use(errorHandler);

errorHandler : Middleware function to handle errors thrown in the application. It should be added at the end of your middleware stack, after all routes.