Summary:
This change moves the default new application template in OSS from Flow to TypeScript. This better aligns with the communities usage, and aligns to the great work that has been happening for TS codegen and built-in types. This used [`react-native-community/react-native-template-typescript`](https://github.com/react-native-community/react-native-template-typescript) as a main reference, maintained by radko93. A few things are different:
1. Updated `types/*` devDependencies to match bumped libraries (e.g. Jest 26 to 20).
2. Removed `types/react-native`
3. Removed explicit `moduleFileExtensions` to Jest config in package.json (TS and TSX and added by default in current versions)
4. Removed overrides to eslint config to disable `no-shadow` and `no-undef`, since this was fixed in the underlying eslint config with https://github.com/facebook/react-native/pull/32644 and https://github.com/facebook/react-native/pull/32655
5. Re-translated `App.js` to be a direct translation (e.g. still a raw function instead of React.FC which is sometimes discouraged)
6. Aligns completely to `tsconfig/react-native` maintained configuration (We no longer have the opinionated override of `skipLibCheck`). The important settings are that `strict` is enabled for, but `allowJS` is also enabled to let users import JS modules without anything unexpected. `esModuleInterop` is enabled, which is needed for consistency with Babel import transformations used by Metro. Consistent with our [current documentation](https://reactnative.dev/docs/typescript) built against the community template, `tsc` will typecheck your code without emitting(building) anything.
[Documentation](https://reactnative.dev/docs/typescript) will need to be updated as a followup.
Changelog:
[General][Changed] - Use TypeScript by default for new applications
Pull Request resolved: https://github.com/facebook/react-native/pull/35165
Test Plan: Added usage of `tsc` and `jest` when validating a newly built app. Passes in CircleCI `test_js` job. This also meant removing some cases of copying packages into the users app to pull in the root Metro config (we seem to be able to use the template Metro config consistent with what real apps would get).
Reviewed By: cortinico
Differential Revision: D40911951
Pulled By: NickGerleman
fbshipit-source-id: 15994534235695e91cf994ad06ba2183dfc89a50
Summary: This diff moves the React Native template from `local-cli/templates/HelloWorld` to `template`. Keeping it in the react-native repo will allow us to make changes to the template and version it together with react-native, instead of moving it out into a separate repo and trying to keep the template in sync with RN.
Reviewed By: TheSavior
Differential Revision: D13372949
fbshipit-source-id: e68e267b4dcf6384535d7b48fc11e297a12e9676
Nick Gerleman
Andres Suarez
Christoph Nakazawa