This is a pretty basic library to facilitate error handling in express APIs
Table of content:
npm install @knfcz/http-errors
or
yarn add @knfcz/http-errors
Use the included middleware as the last middleware in your express API
// server.js
const { withErrorHandling } = require('@knfcz/http-errors');
// Your middlewares here...
app.use(cors());
app.use(router);
// ...and the error handling mw here
app.use(
withErrorHandling({
logError: true,
}),
);Once the middleware is set up, you can throw some HTTP errors, their code and HTTP status will be used to respond to the client
If a different kind of error is caught, the middleware will respond with a 500 HTTP status
| Name | Code | HTTP Status | Description |
|---|---|---|---|
| AccessForbiddenError | accessForbidden | 403 | Client don't have access to this resource |
| ExpiredTokenError | expiredToken | 403 | Client authentication token expired |
| InvalidCredentialsError | invalidCredentials | 400 | Client login failed |
| InvalidParametersError | invalidParameters | 400 | Invalid body/params/headers |
| ResourceConflictError | resourceConflict | 409 | Cannot create or update a resource |
Example:
// http/controllers/article.js
const { MissingResourceError } = require('@knfcz/http-errors');
const getArticle = async (req, res, next) => {
const id = req.params.id;
try {
const article = await Article.find(id);
res.json({ data: article });
} catch (error) {
next(new MissingResourceError());
}
};This will send a json response with a 404 status and this body:
{
"errorCode": "missingResource",
"payload": {}
}Note: if you use express v5+ and your handler returns a promise, you can actually throw the error instead of calling next
If you want to pass some additional data to the client, you can pass an object to the error's constructor
throw new MissingResourceError({
id: 6,
resource: 'article',
});will send the following body
{
"errorCode": "missingResource",
"payload": {
"id": 6,
"resource": "article"
}
}You can extend the base class to create your own HTTP errors:
// http/errors/FuckYouError.js
const { HTTPError } = require('@knfcz/http-errors');
class FuckYouError extends HTTPError {
constructor(payload = {}) {
super({
code: 'fuckYou',
httpStatus: 500,
payload,
});
}
}
module.exports = FuckYouError;