this.$forceUpdate changes

[DellCliff]

Version

3.2.31

Reproduction link

sfc.vuejs.org/

Steps to reproduce

let beforeMountForceUpdate;
let beforeUnmountForceUpdate;

beforeMount() {
beforeMountForceUpdate = this.$forceUpdate;
listenable.addEventListener("change", this.$forceUpdate);
},

beforeUnmount() {
beforeUnmountForceUpdate = this.$forceUpdate;
console.log(beforeMountForceUpdate === beforeUnmountForceUpdate);
listenable.removeEventListener("change", this.$forceUpdate);
}

What is expected?

beforeMountForceUpdate === beforeUnmountForceUpdate

What is actually happening?

beforeMountForceUpdate !== beforeUnmountForceUpdate

---

Results in memory leaks.

[zscumt123]

in Lifecycle Hooks, 'this' is proxy, eg.

const fnObj = {
// return a function
  $forceUpdate: () => () => console.log('fn')
}
const obj = {}
const proxy = new Proxy(obj, {
  get(target, key) {
    if (fnObj[key]) {
      return fnObj[key]()
    }
    return undefined
  }
})
let fn1 = proxy.$forceUpdate
let fn2 = proxy.$forceUpdate
console.log(fn1 === fn2) //false