react-native-webview/docs/Contributing.md

# Contributing to React Native WebView

First off, _thank you_ for considering contributing to the React Native Community. The community-supported packages are only possible because of amazing people like you.

Secondly, we'd like the contribution experience to be as good as possible. While we are a small all-volunteer team, we are happy to hear feedback about your experience, and if we can make the docs or experience better please let us know.

## How to test changes

After you fork the repo, clone it to your machine, and make your changes, you'll want to test them in an app.

In a new `react-native init` project, do this:

```
$ yarn add ../react-native-webview
$ react-native link react-native-webview
```

You may run into a problem where the `jest-haste-map` module map says react-native was added twice:

```
Loading dependency graph...(node:32651) UnhandledPromiseRejectionWarning: Error: jest-haste-map: Haste module naming collision:
  Duplicate module name: react-native
  Paths: /Users/myuser/TestApp/node_modules/react-native/package.json collides with /Users/myuser/TestApp/node_modules/react-native-webview/node_modules/react-native/package.json
```

Just remove the second path like this:

```
$ rm -rf ./node_modules/react-native-webview/node_modules/react-native
```

And then re-run the packager:

```
$ react-native start --reset-cache
```

When you make a change, you'll probably need to unlink, remove, re-add, and re-link `react-native-webview`:

```
$ react-native unlink react-native-webview && yarn remove react-native-webview
$ yarn add ../react-native-webview && react-native link react-native-webview
```

## Notes

- We use Flow types. TypeScript types will probably be added at a later date.
- We don't intend to support UIWebView and will remove it soon.
- After pulling this repo and installing all dependencies, you can run flow on iOS and Android-specific files using the commands:
  - `yarn test:ios:flow` for iOS
  - `yarn test:android:flow` for Android
- You can run Jest tests using the command: `yarn test:js`
- If you want to add another React Native platform to this repository, you will need to create another `.flowconfig` for it. If your platform is `example`, copy the main flowconfig and rename it to `.flowconfig.example`. Then edit the config to ignore other platforms, and add `.*/*[.]example.js` to the ignore lists of the other platforms. Then add an entry to `package.json` like this:
  - `"test:example:flow": "flow check --flowconfig-name .flowconfig.example"`
- Currently you need to install React Native 0.57 to be able to test these types - `flow check` will not pass against 0.56.