https://github.com/ladjs/koa-better-error-handler
A better error-handler for Lad and Koa. Makes `ctx.throw` awesome (best used with koa-404-handler)
https://github.com/ladjs/koa-better-error-handler
boom error error-handler error-handling flash flash-messages handler koa messages node stripe validation
Last synced: 5 months ago
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A better error-handler for Lad and Koa. Makes `ctx.throw` awesome (best used with koa-404-handler)
- Host: GitHub
- URL: https://github.com/ladjs/koa-better-error-handler
- Owner: ladjs
- License: mit
- Created: 2016-07-24T09:42:04.000Z (almost 9 years ago)
- Default Branch: master
- Last Pushed: 2023-02-14T22:04:44.000Z (about 2 years ago)
- Last Synced: 2024-12-10T08:51:22.548Z (5 months ago)
- Topics: boom, error, error-handler, error-handling, flash, flash-messages, handler, koa, messages, node, stripe, validation
- Language: JavaScript
- Homepage: https://lad.js.org
- Size: 859 KB
- Stars: 53
- Watchers: 7
- Forks: 9
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# koa-better-error-handler
[](https://github.com/ladjs/koa-better-error-handler/actions/workflows/ci.yml)
[](https://github.com/sindresorhus/xo)
[](https://github.com/prettier/prettier)
[](https://lass.js.org)
[](LICENSE)
> A better error-handler for [Lad][] and [Koa][]. Makes `ctx.throw` awesome (best used with [koa-404-handler][])
## Index
* [Features](#features)
* [Install](#install)
* [Usage](#usage)
* [API](#api)
* [Web App](#web-app)
* [User-Friendly Responses](#user-friendly-responses)
* [HTML Error Lists](#html-error-lists)
* [License](#license)
## Features
* Detects Node.js DNS errors (e.g. `ETIMEOUT` and `EBADFAMILY`) and sends 408 Client Timeout error
* Detects Mongoose errors and sends 408 Client Timeout error
* Detects common programmer mistakes by detecting errors of TypeError, SyntaxError, ReferenceError, RangeError, URIError, and EvalError and yields generic "Internal Server Error" (only applies to production mode)
* Detects Redis errors (e.g. ioredis' MaxRetriesPerRequestError) and sends 408 Client Timeout error
* Uses [Boom][boom] for making error messages beautiful (see [User Friendly Responses](#user-friendly-responses) below)
* Simply a better error handler (doesn't remove all headers [like the built-in one does][gh-issue])
* Doesn't make all status codes 500 ([like the built-in Koa error handler does][gh-500-issue])
* Supports Flash messages and preservation of newly set session object
* Fixes annoying redirect issue where flash messages were lost upon an error being thrown
* Supports [HTML Error Lists](#html-error-lists) using `
- ` for Mongoose validation errors with more than one message
- `.
Therefore if you *DO* want your API error messages to return HTML formatted error lists for Mongoose validation, then set `app.context.api = false`, `ctx.api = false`, or simply make sure to not set them before using this error handler.
```js
try {
// trigger manual validation
// (this allows us to have a 400 error code instead of 500)
await company.validate();
} catch (err) {
ctx.throw(Boom.badRequest(err));
}
```> With error lists:
```json
{
"statusCode": 400,
"error": "Bad Request",
"message": "- Path `company_logo` is required.
- Gig description must be 100-300 characters.
}
```> Without error lists:
```json
{
"statusCode":400,
"error":"Bad Request",
"message":"Path `company_logo` is required., Gig description must be 100-300 characters."
}
```## API Friendly Messages
By default if `ctx.api` is true, then [html-to-text](https://github.com/werk85/node-html-to-text) will be invoked upon the `err.message`, thus converting all the HTML markup into text format.
You can also specify a base URI in the environment variable for rendering as `process.env.ERROR_HANDLER_BASE_URL`, e.g. `ERROR_HANDLER_BASE_URL=https://example.com` (omit trailing slash), and any HTML links such as `Click here` will be converted to `[Click here][1]` with a `[1]` link appended of `https://example.com/foo/bar/baz`.
## License
[MIT](LICENSE) © [Nick Baugh](http://niftylettuce.com/)
##
[boom]: https://github.com/hapijs/boom
[gh-issue]: https://github.com/koajs/koa/issues/571
[gh-500-issue]: https://github.com/koajs/koa/blob/e4bcdecef295d7adbf5cce1bdc09adc0a24117b7/lib/context.js#L94-L140
[mongoose-beautiful-unique-validation]: https://github.com/matteodelabre/mongoose-beautiful-unique-validation
[lad]: https://lad.js.org
[koa]: http://koajs.com/
[koa-404-handler]: https://github.com/ladjs/koa-404-handler
[cabin]: https://cabinjs.com
* Makes `ctx.throw` beautiful messages (e.g. `ctx.throw(404)` will output a beautiful error object :hibiscus:)
* Supports `text/html`, `application/json`, and `text` response types
* Supports and recommends use of [mongoose-beautiful-unique-validation][mongoose-beautiful-unique-validation]
## Install
```bash
npm install --save koa-better-error-handler
```
## Usage
> You should probably be using this in combination with [koa-404-handler][] too!
The package exports a function which accepts four arguments (in order):
* `cookiesKey` - defaults to `false`
* `logger` - defaults to `console`
* `useCtxLogger` - defaults to `true`
* `stringify` - defaults to `fast-safe-stringify` (you can also use `JSON.stringify` or another option here if preferred)
If you pass a `cookiesKey` then support for sessions will be added. You should always set this argument's value if you are using cookies and sessions (e.g. web server).
We recommend to use [Cabin][] for your `logger` and also you should use its middleware too, as it will auto-populate `ctx.logger` for you to make context-based logs easy.
Note that this package only supports `koa-generic-session`, and does not yet support `koa-session-store` (see the code in [index.js](index.js) for more insight, pull requests are welcome).
### API
> No support for sessions, cookies, or flash messaging:
```js
const errorHandler = require('koa-better-error-handler');
const Koa = require('koa');
const Router = require('koa-router');
const koa404Handler = require('koa-404-handler');
// initialize our app
const app = new Koa();
// override koa's undocumented error handler
app.context.onerror = errorHandler();
// specify that this is our api
app.context.api = true;
// use koa-404-handler
app.use(koa404Handler);
// set up some routes
const router = new Router();
// throw an error anywhere you want!
router.get('/404', ctx => ctx.throw(404));
router.get('/500', ctx => ctx.throw(500));
// initialize routes on the app
app.use(router.routes());
// start the server
app.listen(3000);
console.log('listening on port 3000');
```
### Web App
> Built-in support for sessions, cookies, and flash messaging:
```js
const errorHandler = require('koa-better-error-handler');
const Koa = require('koa');
const redis = require('redis');
const RedisStore = require('koa-redis');
const session = require('koa-generic-session');
const flash = require('koa-connect-flash');
const convert = require('koa-convert');
const Router = require('koa-router');
const koa404Handler = require('koa-404-handler');
// initialize our app
const app = new Koa();
// define keys used for signing cookies
app.keys = ['foo', 'bar'];
// initialize redis store
const redisClient = redis.createClient();
redisClient.on('connect', () => app.emit('log', 'info', 'redis connected'));
redisClient.on('error', err => app.emit('error', err));
// define our storage
const redisStore = new RedisStore({
client: redisClient
});
// add sessions to our app
const cookiesKey = 'lad.sid';
app.use(
convert(
session({
key: cookiesKey,
store: redisStore
})
)
);
// add support for flash messages (e.g. `req.flash('error', 'Oops!')`)
app.use(convert(flash()));
// override koa's undocumented error handler
app.context.onerror = errorHandler(cookiesKey);
// use koa-404-handler
app.use(koa404Handler);
// set up some routes
const router = new Router();
// throw an error anywhere you want!
router.get('/404', ctx => ctx.throw(404));
router.get('/500', ctx => ctx.throw(500));
// initialize routes on the app
app.use(router.routes());
// start the server
app.listen(3000);
console.log('listening on port 3000');
```
## User-Friendly Responses
> Example Request:
```bash
curl -H "Accept: application/json" http://localhost/some-page-does-not-exist
```
> Example Response:
```json
{
"statusCode": 404,
"error": "Not Found",
"message":"Not Found"
}
```
## Prevent Errors From Being Automatically Translated
As of v3.0.5, you can prevent an error from being automatically translated by setting the error property of `no_translate` to have a value of `true`:
```js
function middleware(ctx) {
const err = Boom.badRequest('Uh oh!');
err.no_translate = true; // <----
ctx.throw(err);
}
```
## HTML Error Lists
If you specify `app.context.api = true` or set `ctx.api = true`, and if a Mongoose validation error message occurs that has more than one message (e.g. multiple fields were invalid) – then `err.message` will be joined by a comma instead of by `