proxy（私人仓库）

1、

2、

let p = new Proxy(target, handler)

3、

let onWatch = (obj, setBind, getLogger)=> {
    let handler = {
        get(target, property, receiver) {
           getLogger(target, property)
            return Reflect.get(target, property, receiver)
        },
        set(target, property, value, receiver) {
            setBind(value, property)
            return Reflect.set(target, property, value)
        }
    }
    return new Proxy(obj, handler)
}
let obj = { a: 1 }
let p = onWatch(obj,(v, property) => {
    console.log(`监听到属性${property}改变为${v}`)
},(target, property) => {
        console.log(`'${property}' = ${target[property]}`)
})
p.a = 2 // 监听到属性a改变
p.a // 'a' = 2