Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/36345
`exactOptionalPropertyTypes` is a TypeScript 4.4+ option set by users which changes behavior of optional properties, to disable accepting explicit `undefined`.
This is not enabled when using `--strict`, and is stricter than Flow, leading to most of the typings having an `| undefined` unique to TypeScript (added with https://github.com/DefinitelyTyped/DefinitelyTyped/commit/694c663a9486dbe7794d5eb894a691ee9ded318a).
We have not always followed this (I have myself previously assumed the two are equivalent). We can enforce that the convention is followed with a plugin `eslint-plugin-redundant-undefined`. This forces us to declare that every optional property accepts an explicit undefined (which Flow would allow). Alternatively, if we do not want to support this, we can enable the existing dtslint rule `no-redundant-undefined`.
Changelog:
[General][Fixed] - Enforce compatibility with `exactOptionalPropertyTypes`
Reviewed By: lunaleaps
Differential Revision: D43700862
fbshipit-source-id: 996094762b28918177521a9471d868ba87f0f263
Summary:
React Native's TS definitions are currently mostly stored in one monolithic file. This change splits the definitions up to correspond to the source files they came from, and are placed next to the source files. I think this should help inform, and make it easy to update the TS declarations when touching the Flow file.
I noticed as part of the change that the typings have not yet removed many APIs that were removed from RN. This is bad, since it means using the removed/non-functional API doesn't cause typechecker errors. Locating typings next to source should prevent that from being able to happen.
The organization here means individual TS declarations can declare what will be in the RN entrypoint, which is a little confusing. Seems like a good potential next refactor, beyond the literal translation I did.
Changelog:
[General][Changed] - Place TS Declarations Alongside Source Files
Reviewed By: lunaleaps, rshest
Differential Revision: D39796598
fbshipit-source-id: b36366466fd1976bdd2d4c8f7a4104a33c457a07
Nick Gerleman
Nick Gerleman