Custom-error-exceptions NPM

Custom Error Exceptions

Custom error exceptions are made to make it easier to handling errors. You can also make custom errors as needed.

Installation

$ npm install custom-error-exceptions

Usage

Using Template Error (BAD_REQUEST)

const express = require('express');
const {
  handlers: { errorHandler },
  errors: { BadRequestError }
} = require('custom-error-exceptions');

const app = express();
const port = 3044;
app.use(express.json());

//TEMPLATE BAD REQUEST ERROR 
app.post('/', (req, res) => {
  const name = req.body.name;
  if (typeof name !== 'string') {
    throw new BadRequestError();
  }
  res.send(
    req.body
  );
});

//Error Handler
app.use(errorHandler);
app.listen(port, () => console.log(`app listen on port ${port}`));

Using Template Error (BAD_REQUEST) With Custom Message

//TEMPLATE BAD REQUEST ERROR WITH CUSTOM MESSAGE
app.post('/custom-message', (req, res) => {
  const name = req.body.name;
  if (typeof name !== 'string') {
    throw new BadRequestError('Name type must be string');
  }
  res.send(req.body);
});

Using Custom Error

const {
  handlers: { errorHandler },
  errors: { CustomError }
} = require('custom-error-exceptions');

//CUSTOM ERROR
app.post('/custom-error', (req, res) => {
  const name = req.body.name;
  if (typeof name !== 'string') {
    throw new CustomError('Custom Message', 'CUSTOM_CODE', 700);
  }
  res.send(req.body);
});

Handling NOT_FOUND Route

const {
  handlers: { errorHandler, notFoundHandler },
} = require('custom-error-exceptions');

------------------------------------
             YOUR ROUTE
------------------------------------

app.use(notFoundHandler);
app.use(errorHandler);

How to handle UnhandledRejection for Async Function in Express

const {
  handlers: { createHandler }
} = require('custom-error-exceptions');

const getName = async (req, res) => {
  /*some asynchronous logic here
    example :
    const nameFromDb = await getDataFromDb(req.body.id);
  */
  const id = req.body.id;
  res.send({
    id,
    nameFromDb: 'John Doe'
  })
}

//Implementing in Router
app.post(
  '/unhandled-rejection', 
  createHandler(getName)
);

To further explore you can see an example this repo.

LIST OF ERROR TEMPLATES

CustomError
BadRequestError
UnauthorizedError
PaymentRequiredError
ForbiddenError
NotFoundError
MethodNotAllowedError
NotAcceptableError
ProxyAuthenticationError
RequestTimeoutError
ConflictError
GoneError
LengthRequiredError
PreconditionFailedError
PayloadTooLargeError
UriTooLongError
UnsupportedMediaTypeError
RangeNotSatisfiableError
MisdirectedRequestError
UnprocessableEntityError
LockedError
FailedDependencyError
TooEarlyError
UpgradeRequiredError
PreconditionRequiredError
TooManyRequestsError
RequestHeaderError
LegalReasonsError
InternalServerError
NotImplementedError
BadGatewayError
ServiceUnavailableError
GatewayTimeoutError
HttpNotSupportedError
VariantAlsoNegotiatesError
InsufficientStorageError
LoopDetectedError
NotExtendedError
NetworkAuthenticationRequiredError

The list above is based on the client error list and server error list as on this page.

Version History

version 1.0.0
- Basic Template Errors
- Basic Custom Error
- Error Handler
- Not Found Route Handler for Express

version 1.1.0
- Create middleware function to handling 'UnhandledRejection' for asynchronous route in Express
version 1.2.0
- Adding logging middleware in every request with winston
version 1.2.1
- Adding and showing error logger to console if request error
version 1.2.2
- Adding handler with view engine (createWebHandler)
version 1.2.3
- Handling response message when handler get Unhandled Exceptions error message from asynchronous router
version 1.2.4
- Minor security update for Mocha and Nodemon