14. 实现中间件的挂载(compose函数)

[senfish]

let middlewares = [
  (str) => {
    return str + '1'
  },
  (str) => {
    return str + '2'
  },
  (str) => {
    return str + '3'
  },
  (str) => {
    return str + '4'
  }
]

function compose(arr) {
  ...
}
const add = compose(middlewares);
add('hello'); // hello4321

[senfish]

function compose(arr) {
  return arr.reduce((acc, cur) => {
    return (...args) => acc(cur(...args))
  })
}