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

[LmonZero]

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)
  

  })

}

}