fix: make proxy a no-op when passed a proxy

[aleclarson]

Summary

As far as I can tell, there's no benefit to wrapping a Valtio proxy with proxy(…) but it can happen inadvertently. In this case, Valtio should simply return the proxy unchanged, since it's already subscribable.

In valtio-kit, I'm using proxy(new Foo()) as a compiler hint, so the compiler can know to wrap references to the Foo instance with get(…) inside of watch handlers. In my testing of this compiler hint, I found this undesirable Valtio behavior of “proxying a proxy”.

Check List

• pnpm run fix:format for formatting code and docs

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Name	Status	Preview	Comments	Updated (UTC)
valtio	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 20, 2025 7:43pm

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commit: 6511f29

[dai-shi]

I'm not sure if I can explain this well, but it feels like there might be a case where we want wrapping proxies again. Adding the proposed check will prevent such a use case, so this isn't acceptable at the moment. Adding the same check with a wrapper is technically possible.

I assume you have your solution on valtio-kit without changing valtio, and this is just to let us know this should be an expected behavior. Thanks for the suggestion anyway.