Summary:
In development, we can specify a debug name to force the whole React tree to have a meaningful name. This is useful for debugging: React DevTools, component stack traces, etc. More context in D26637787 (https://github.com/facebook/react-native/commit/eeb36f470929c2fdd8e1ed69898a5ba9144b8715).
This worked fine until now because `renderApplication` is never called more than once per React Native root. With pre-rendering, this won't be true as we'll be able to re-render the whole React tree with new props (after navigating to the screen).
The problem with the current implementation is that we generate a new component every time `renderApplication` is called, which makes the React reconciliation consider them different components and discards the whole sub-tree.
This fixes it by caching those components so we always return a component with the same identity (exactly the same function) when we call `renderApplication` repeatedly.
This won't have any effect in production where these components aren't created at all.
Changelog: [Internal]
Reviewed By: ShikaSD
Differential Revision: D28061384
fbshipit-source-id: 95833a5b74bb622896cb47426f74324d8740e5d7
Rubén Norte