With the React Compiler, our component code is transformed at build time to automatically apply various forms of memoization. This changes the runtime semantics of our code a little bit and therefore could surface new bugs in the next release cycle in case any components fail to follow the rules of React. See https://react.dev/learn/react-compiler for more information.
This results in a small bundle size increase and modest performance gains, but I think it's worth it given the potential for larger performance gains once we tune the component structure a bit more.
* Avoid reactivity bugs in how we track external state
Many of our hooks which attempt to bridge external state from an EventEmitter or EventTarget into React had subtle bugs which could cause them to fail to react to certain updates. The conditions necessary for triggering these bugs are explained by the tests that I've included.
In the majority of cases, I don't think we were triggering these bugs in practice. They could've become problems if we refactored our components in certain ways. The one concrete case I'm aware of in which we actually triggered such a bug was the race condition with the useRoomEncryptionSystem shared secret logic (addressed by a1110af6d5).
But, particularly with all the weird reactivity issues we're debugging this week, I think we need to eliminate the possibility that any of the bugs in these hooks are the cause of our current headaches.
* Reuse useTypedEventEmitterState in useLocalStorage
* Fix type error
