mount connect/express to koa

mount-connect-or-express-to-koa.js

import koa from 'koa'
import middlewareForExpressOrConnect from './path/some-middleware'

const app = new koa()

app.use(async (ctx, next) => {
  const { req, res } = ctx
  return new Promise((resolve, reject) => {
    middlewareForExpressOrConnect(req, res, (err) => {
      if (err) {
        reject(err)
      } else {
        next().then(resolve)
      }
    })
  })
})