Vue.js设计与实现无限递归学习总结

const data = { foo: 1 }
const obj = new Proxy(data, {/*...*/})
effect(() => obj.foo = obj.foo + 1)

Uncaught RangeError: Maximum call sack size exceeded

function trigger (target, key) {
    const depsMap = bucket.get(target)
    if (!depsMap) return
    const effects = depsMap.get(key)
    const effectsToRun = new Set()
    effects && effects.forEach(effectFn => {
        if (effectFn !== activeEffect) {
            effectsToRun.add(effectFn)
        }
    })
    effectsToRun.forEach(effectFn => effectFn())
}

// 储存副作用函数的桶
  const bucket = new WeakMap()
  // 用于储存被注册的副作用的函数
  let activeEffect = undefined
  // 副作用函数栈
  const effectStack = []
  function cleanup (effectFn) {
    for (let itme of effectFn.deps) {
      itme.delete(effectFn)
    }
    effectFn.deps.length = []
  }
  function effect (fn) {
    const effectFn = () => {
        cleanup(effectFn)
        // 调用当前的副作用函数时, 赋值给 全局变量
        activeEffect = effectFn
        // 在调用副作用函数之前将该函数压入栈
        effectStack.push(effectFn)
        fn()