Function setup

packages/reactivity/__tests__/computed.spec.ts:815–822

()

    const Child = {
      setup() {
        const b = computed(() => a.value + 1)
        const c = computed(() => b.value + 1)
        // access
        c.value
        onUnmounted(() => spy(c.value))
        return () => {}
      },
    }

    const show = ref(true)