Abnormal middleware errors occurred and KOA could not catch error events. How about the following changes

```
function compose (middleware) {
if(!Array.isArray(middleware)) throw TypeError('Middleware stack must be an array!')
for (const fn of middleware) {
if(typeof fn !== 'function') throw new TypeError('Middleware must be composed of functions!')
}

let index = -1 //

/**
* @param {Object} context
* @return {Promise}
* @api compose
*/
return function (context, next) {
return new Promise((resolve, reject) => {
function dispatch (i) { //
if (i <= index) {
console.warn('[warn]next() called multiple times')
return //reject(new Error('next() called multiple times'))
}

index=i
let fn=middleware[i]
if(i===middleware.length) fn=next //
if(!fn) return resolve()

try {
return resolve(fn(context,dispatch.bind(null,i+1)))
} catch (error) {
return reject(error)
}

}
dispatch(0)
})

}

}
```

Start with the compose function shown in the issue and reproduce the abnormal middleware error behavior. No repository files or tests are named, and the issue does not define the expected error-handling behavior beyond saying that Koa cannot catch error events, so the acceptance criteria need clarification before implementation.

Written by the indexing model from the issue text.