It's a koa middleware. Dependency on koa@2.
When i use koa to dev my project that find everytime i have to handler exception at the route.
For example, a method maybe throws MongoError or other errors called by route,so you always must handler it.
However, that's a not good way to do bussiness.
Use koa-exception, what you need do is that focus on your bussiness.
npm install koa-exception --save
app.js
var app = require('koa')();
var KoaEx = require('koa-exception');
/** NOTE:
KoaEx must be used first before any other middleware, and then
it will catch all of the exception throwed by route,dao and os.
*/
app.use(KoaEx());
var port = 3000;
app.listen(port, function() {
console.log('Server running on port ' + port);
});