errors-express
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1.2.0 • Public • Published

Errors for Express

Easy error handling for Express APIs.

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Installation

Install together with express

npm i express errors-express

Usage

Import the error handler middleware and place it at the end of the middleware stack. Any error (operational or not) thrown by a controller is handled and sent to the client.

Use the handler with a callback to perform extra actions such as logging. Callback receives the error and the request object.

Use guards to return a custom error response after not found or not allowed methods requests.

import express from 'express';
import errorHandler, { Errors, Guards } from 'errors-express';

const app = express();

app.get('/protected', async (req, res) => {
  throw Errors.Unauthorized('You must first sign in');
});

app.all('*', Guards.NotFound());

app.use(errorHandler((error, req) => {
  console.log(`[${req.method} ${req.url}] ${error.message}`);
}));

app.listen(process.env.PORT || 3000);

Errors

The base error class used by the package is HttpError. Send optional error details, useful for providing context to error handling in frontend.

HttpError(statusCode, message, details?)

Details can be a string or an object that contains an error code, message and a free context object

Default errors are provided by the package, just include optional message and details.

import { HttpError, Errors } from 'errors-express';

throw new HttpError(400, 'Invalid request', 'MISSING_PSWD');

throw Errors.NotFound();
throw Errors.Forbidden('You cannot do this');
throw Errors.TooManyRequests('You reached the maximum limit or requests', {
  code: 'REQUEST_LIMIT_REACHED';
  message: 'You reached the maximum limit or requests';
  ctx: {
    maxRequests: 5,
    retryIn: '1min',
  };
});
Error statusCode Default message
BadRequest 400 The request syntax is invalid
Unauthorized 401 The authentication credentials are invalid
Forbidden 403 You are not allowed to use this resource
NotFound 404 This resource does not exist
MethodNotAllowed 405 This method is not allowed for this resource
Conflict 409 There is a conflict with the current state of the resource
Unprocessable 422 The request is unprocessable
TooManyRequests 429 The maximum number of requests has been exceeded
InternalServer 500 An internal server error occurred

Guards

Guards automatically return an error if none of the previous handlers are called.

import { Guards } from 'errors-express';

app.get('/resource', ResourceController);

app.use(Guards.MethodNotAllowed());
app.use(Guards.NotFound()),

Only MethodNotAllowed and NotFound are available.

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Install

npm i errors-express

Weekly Downloads

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Version

1.2.0

License

ISC

Unpacked Size

31.4 kB

Total Files

41

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Collaborators

  • markusand