Summary:
The PlatformConstants native module exposes the ability to query the React
Native version used to build native code. This is managed on iOS and Android by
a version bumping script, which replaces module code based on a template.
It is currently difficult to accurately determine this version for out-of-tree C++
platforms (I.e. React Native Windows). The version of upstream react-native we resolve to is ultimately
dependent on the version of react-native chosen a peer dependency, which is not
neccesarily constant given a build of react-native-windows.
We could try to hack around this, and make our native build try to reason about
the resolved pacakge for react-native using a lockfile, but a much cleaner
solution is to embed version into C++ code, similar to what is done for Android
and iOS. This change does that, adding a header with React Native version and
updating the build stamping script to write to it.
Usage sample:
```c++
constants["reactNativeVersion"] = folly::dynamic::object();
constants["reactNativeVersion"]["major"] = ReactNativeVersion.Major;
constants["reactNativeVersion"]["minor"] = ReactNativeVersion.Minor;
constants["reactNativeVersion"]["patch"] = ReactNativeVersion.Patch;
```
## Changelog
[General] [Added] - Stamp React Native Version Into C++ Code
Pull Request resolved: https://github.com/facebook/react-native/pull/28036
Test Plan: Validated that the bumping script will accurately update the header, can compile under both MSVC and Clang.
Differential Revision: D19865992
Pulled By: hramos
fbshipit-source-id: 9e0b8e9519015bb62c60b9935a234cd367a1926a
427ba359e0