fix(deepEqual): support objects with null prototypes

[iamakulov]

While reviewing a project crash for a client, I discovered that the deepEqual function (invoked by getConnectors) crashes if some field inside a connector is an object without a prototype:

const a = Object.create(null)

if (a.valueOf !== Object.prototype.valueOf)
    return a.valueOf() === b.valueOf();
          // ↑ fails with “TypeError: a.valueOf is not a function” since an object
          // with no prototype will have `a.valueOf === undefined`

This PR fixes that.

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[changeset-bot]

🦋 Changeset detected

Latest commit: 295babd

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 4 packages

Name	Type
@wagmi/core	Patch
@wagmi/connectors	Patch
wagmi	Patch
@wagmi/vue	Patch

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[iamakulov]

Dug deeper into this. Another issue this deepEqual implementation has is it also crashes with Maximum call stack size exceeded if any passed object has circular references.

Critically, it’s pretty easy to end up that state. I still don’t have the full picture of how exactly it’s happening, but it appears that:

• Wagmi adds an emitter (instance of eventemitter3) object onto every connector created through it. This object has both __proto__ === null and a circular reference to itself
• Whenever you call getConnectors(), Wagmi deep-compares previous and new connectors
• So if you ever recreate a connector from scratch (which can easily happen during SSR, where the React state gets reset on every request), Wagmi will end up deep-comparing the previous and the new connector – and crashing inside deepEqual when it tries to compare emitter objects

I guess the answer to this is “don’t store Wagmi connectors in your React state, duh”. But it would’ve been nice if Wagmi had a better DX around this (rather than just crashing with a.valueOf is not a function or Maximum call stack size exceeded).