SOURCE

let effectMap = new Map()
let activeEffect = null       // 副作用标识 用于 注册
const reactive = (data) => {
   return new Proxy(data, {
      set(target, key, value) {
          target[key] = value
         let effectSet = effectMap.get(key)
         effectSet && effectSet.forEach(fn => fn() )
         
      },
      get(target, key) {
         if(activeEffect){
              let effectSet = effectMap.get(key) || new Set() 
              effectSet.add(activeEffect)
              effectMap.set(key,effectSet)
          }
         return target[key]
      }
   })
}
let data = reactive({ name: 'name', age: 20 })
let state = reactive({ name: 'state', age: 20 })

const regeisterEffect = (fn) => {
    if(typeof fn !== 'function') return 
    activeEffect = fn 
    fn() 
    activeEffect = null 
}

regeisterEffect(function effectName(){
    console.log(25, data.name)
})
console.log(32,effectMap )

setTimeout(function () {
   data.name = 'change name '
   console.log(36,data)
}, 300)