Mutating a shallowRef object using $patch doesn't trigger reactivity

[nguyenalter]

Reproduction

https://stackblitz.com/edit/github-5ayhfs4m?file=src%2FApp.vue

Steps to reproduce the bug

1. Define a shallowRef state (e.g. const counter = shallowRef({ count: 0 })) using setup stores syntax
2. Use the store in a Vue component
3. Update the state using $patch({ counter: { count: 1 }) syntax
4. The state is updated in store but the reactivity is not triggered

Expected behavior

At step 4, the Vue's reactivity system should trigger

Actual behavior

At step 4, the Vue's reactivity system does not trigger (no watcher/computed run after the state change)

Additional information

In the playground, I tested with two other ways to update the shallowRef's state, and the reactivity still works normally:

const counterStore = useCounterStore();
// Using $patch with update function: trigger reactivity
counterStore.$patch((state) => {
    state.counter2 = { count: state.counter2.count + 1 };
  });
// Direct mutate the state: trigger reactivity
counterStore.counter3 = { count: ... };

[posva]

This is inherent to how shallowRef work. You can use the other ways to call triggerRef().

That being said, it's possible to make this work by calling triggerRef when a key of a shallow object is traversed for the $patch(patchObject)`. For the function syntax, it's up to the user to properly handle this.