feat: Add TurboModuleRegistry.getLazy<T>(..)

[mrousavy]

Summary:

Adds TurboModuleRegistry.getLazy to get a module lazily:

const NativeMmkv = TurboModuleRegistry.getLazy<MmkvSpec>('MmkvCxx')
// ^ MmkvCxx will not yet be loaded here.

NativeMmkv.getString('test')
// ^ now MMKV will be loaded, and it will throw an error if the module is not found

Instead of requiring the module as soon as JS parses the file, it will only require the module once you try to access a property or function on the object (via a Proxy).

The idea is to increase performance and potentially also memory usage by avoiding eagerly loading modules if they are not needed immediately (e.g. only in a render function later on)

Changelog:

[GENERAL] [ADDED] Add TurboModuleRegistry.getLazy<T>(...) to lazy-load TurboModules

Test Plan:

I think we want to add this to the unit tests, right? In addition to get and getEnforcing. Not sure how those tests are set up, how do I run them?

The way I tested this was within my react-native-mmkv project by just editing RN in node_modules, and that worked :)

[RSNara]

@mrousavy, in general, we want to discourage people from using Proxy. It's extremely slow: I've seen ~20x slowdown quoted internally (for Hermes). And, it may preclude some compile-time optimizations we might want to ship to react native the framework.

So, unfortunately, we cannot ship this addition to the core.

[mrousavy]

Gotcha, makes sense. I didn't know about these slowdowns, I'll keep that in mind when working on react-native-mmkv - thanks!