A react-native doctor is a new command to help you out with getting started, troubleshooting and automatically fixing errors with your development environment.
- The doctor command currently supports most of the software and libraries that React Native relies on.
- Doctor will find issues with your development environment and give you the option to automatically fix them.
- If doctor is not able to fix an issue, it will display a message and a helpful link explaining how to fix it manually.
The doctor command is heavily inspired by Expo and Homebrew's own doctor command with a pinch of UI inspired by Jest.
https://facebook.github.io/react-native/blog/2019/11/18/react-native-doctor 
