TypeError: Cannot read property 'type' of null at unmountComponent

[PingTouG]

Version

3.0.0-rc.5

Reproduction link

https://github.com/PingTouG/layer

Steps to reproduce

leave "/componnets/container" router

What is expected?

to other router

What is actually happening?

TypeError: Cannot read property 'type' of null at unmountComponent

[underfin]

I tracked for this and the blew is a mini-reproduction.Maybe we should internal provider a safer getter for computed and customRef?

<script src="./dist/vue.global.js"></script>
<div id="app"></div>
<script>
  const {createApp, computed, setBlockTracking} = Vue
  // this can fix this.
  function saferGetter(getter) {
    return () => {
      setBlockTracking(-1)
      const res = getter()
      setBlockTracking(1)
      return res
    }
  }

  const Parent = {
    template: `
      <section class="c-container" :class="{ 'is-vertical': isVertical }">
        <slot/>
      </section>
    `, setup(props, {slots}) {
      const isVertical = computed(saferGetter(() => {
        // this caused the bug because `computed` getter run inside `render` and collect this into dynamicChildren.
        return !!slots.default()
      }))

      return {
        isVertical
      }
    }
  }

  const Child = {
    template: `<div>child</div>`,
  }

  const app = createApp({
    components: {
      Parent, Child
    }, template: `
      <Parent>
        <Child></Child>
      </Parent>`
  })
  app.mount('#app')

  setTimeout(() => {
    app.unmount('#app')

  }, 3000)
</script>

[PingTouG]

‘saferGetter’ is ok, but muset use this?

[yyx990803]

Hmm, slots is not reactive though, so the computed is pointless...

Also, if you are trying to check for presence of a slot, you should do !!$slots.default in the template (don't call it)

[rendomnet]

I have this error.
Vue3 error log is mess. Cant event udnerstand where it happens