`Object.create` breaks reactivity

[jzjones]

Describe the bug

If you use anything created by Object.create as $state, you will seemingly lose reactivity.

It's trivial to work around in most cases by deep cloning, etc, however I don't see anything that indicates this should be a problem in the first place. This could make it difficult to diagnose why your app is losing reactivity especially when libraries such as https://github.com/bufbuild/protobuf-es use Object.create internally and seem to return ordinary objects.

Reproduction

https://svelte.dev/playground/hello-world?version=5.33.18#H4sIAAAAAAAAA4WTTW_CMAyG_0oWcWglVATH0lXabdoBDhzXHUJrIFtIqsSFoSr_fQn9AlZtl8Z-bSeP46amkh2BxvQVhFDkrLQoSAAFRyhCOqU7LsDQ-L2meCl9nhec3la9lGVkTiDQa1tmYEzPlUSQ6Lahick1LzHNZIZONkhKrVCRZ1J7qTKg48bMEFWhTEw6txHm8eBneGKigphk9DDQZ7SL28a4Lu7jV2cJQIJgcIMMwR08Md4I1ttPyDFixvC9DJrKVss1-IwraThtQj3EHfIN9o0yRn5H7_YX5OpldHqbYwfHjnUVhsuRphZDV-2JD5C_EccAezyFB9Ad3z9EtiPaVTJHriTJD0zuIQj7sXaYkaeKrix-_nb5EF-MJrRTnHBpSjecoE_3Byez4f-SyWGe3k3Q9fe2Wa8ig5rLPd9dgjGW0D4lM1fabLBS-sjEH5WLu9Kuclu5K5VEyVzw_Ou5bi7Bpr4smTXR1D0NhG-kMeoK7IfzGBdnLgsa75gwYH8A5RhHJZ0DAAA=

Logs

System Info

REPL

Severity

annoyance

[paoloricciuti]

This is because Object.create creates an object without the Object.prototype which we use to check if a proxy needs to be proxyfied or not.

Let me see if we can do something about it

[paoloricciuti]

Of course there's no way around it: we don't proxify classes and Object.create is basically a way to create classes...i guess we can document it tho