* Disable React Refresh Babel transform in prod * Throw early if React Refresh runtime is imported in production * @hot reset -> @refresh reset
* Track mounted roots via DevTools Hook * Add helper utilities to the runtime These utilities will likely be needed by all module systems, so let's just put them here. * Wrap more things in __DEV__ * Fix tests to also be DEV-only
* Fall back to Map/Set if Weak equivalents are not available * Fix Prettier vs Flow fighting
Dan Abramov