js 洋葱模型的简单实现

洋葱模型的简单实现， 有人说是compose函数， 无论如何，名字不重要， 先记录下吧， whatever

  <script>

        function onion(middleware) {
            return async function () {
                let args = arguments
                await dispatch(0);
                async function dispatch(i) {
                    const fn = middleware[i]
                    if (!fn) return null
                    await fn(function next() {
                        dispatch(i + 1)
                    }, ...args)
                }
            }
        }

        let middleware = [
            (next) => {
                console.log(0)
                next()
                console.log(4)
            },
            (next) => {
                console.log(1)
                next()
                console.log(3)
            },
            () => {
                console.log(2)
            }
        ]

        let fn = onion(middleware)
        fn()

    </script>
    ```