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)
  })

  }

}