chore: hermes, remove legacy debugging + old config (facebook#4249)

blakef · web-flow · commit dd27a864635e · 2024-10-07T12:15:08.000+01:00
We're moving to the new debugger, so this legacy debugging just muddies
the water. I've also updated the config to remove flipper references.
diff --git a/docs/hermes.md b/docs/hermes.md
@@ -15,9 +15,7 @@ Hermes is used by default by React Native and no additional configuration is req
 ## Bundled Hermes
 
 React Native comes with a **bundled version** of Hermes.
-We will be building a version of Hermes for you whenever we release a new version of React Native. This will make sure you're consuming a version of Hermes which is fully compatible with the version of React Native you're using.
-
-Historically, we had problems with matching versions of Hermes with versions of React Native. This fully eliminates this problem, and offers users a JS engine that is compatible with the specific React Native version.
+We building a version of Hermes for you whenever we release a new version of React Native. This will make sure you're consuming a version of Hermes which is fully compatible with the version of React Native you're using.
 
 This change is fully transparent to users of React Native. You can still disable Hermes using the command described in this page.
 You can [read more about the technical implementation on this page](/architecture/bundled-hermes).
@@ -88,136 +86,7 @@ yarn ios --mode Release
 </TabItem>
 </Tabs>
 
-This will compile JavaScript to bytecode during build time which will improve your app's startup speed on device.
-
-## Debugging JS on Hermes using Google Chrome's DevTools
-
-Hermes supports the Chrome debugger by implementing the Chrome inspector protocol. This means Chrome's tools can be used to directly debug JavaScript running on Hermes, on an emulator or on a real, physical, device.
-
-:::info
-Note that this is very different with the deprecated "Remote JS Debugging" from the In-App Dev Menu documented in the [Debugging](debugging#remote-debugging) section, which actually runs the JS code on Chrome's V8 on your development machine (laptop or desktop) instead of connecting to the JS engine running the app on your device.
-:::
-
-Chrome connects to Hermes running on device via Metro, so you'll need to know where Metro is listening. Typically this will be on `localhost:8081`, but this is [configurable](https://metrobundler.dev/docs/configuration). When running `yarn start` the address is written to stdout on startup.
-
-Once you know where the Metro server is listening, you can connect with Chrome using the following steps:
-
-1. Navigate to `chrome://inspect` in a Chrome browser instance.
-
-2. Use the `Configure...` button to add the Metro server address (typically `localhost:8081` as described above).
-
-![Configure button in Chrome DevTools devices page](/docs/assets/HermesDebugChromeConfig.png)
-
-![Dialog for adding Chrome DevTools network targets](/docs/assets/HermesDebugChromeMetroAddress.png)
-
-3. You should now see a "Hermes React Native" target with an "inspect" link which can be used to bring up debugger. If you don't see the "inspect" link, make sure the Metro server is running. ![Target inspect link](/docs/assets/HermesDebugChromeInspect.png)
-
-4. You can now use the Chrome debug tools. For example, to breakpoint the next time some JavaScript is run, click on the pause button and trigger an action in your app which would cause JavaScript to execute. ![Pause button in debug tools](/docs/assets/HermesDebugChromePause.png)
-
-## Enabling Hermes on Older Versions of React Native
-
-Hermes is the default engine as of React Native 0.70. This section explains how to enable Hermes on older versions of React Native.
-First, ensure you're using at least version 0.60.4 of React Native to enable Hermes on Android or 0.64 of React Native to enable Hermes on iOS.
-
-If you have an existing app based on an earlier version of React Native, you will have to upgrade it first. See [Upgrading to new React Native Versions](/docs/upgrading) for how to do this. After upgrading the app, make sure everything works before trying to switch to Hermes.
-
-:::caution Note for React Native compatibility
-Each Hermes release is aimed at a specific RN version. The rule of thumb is to always follow [Hermes releases](https://github.com/facebook/hermes/releases) strictly.
-Version mismatch can result in instant crash of your apps in the worst case scenario.
-:::
-
-:::info Note for Windows users
-Hermes requires [Microsoft Visual C++ 2015 Redistributable](https://www.microsoft.com/en-us/download/details.aspx?id=48145).
-:::
-
-### Android
-
-Edit your `android/gradle.properties` file and make sure `hermesEnabled` is true:
-
-```diff
-# Use this property to enable or disable the Hermes JS engine.
-# If set to false, you will be using JSC instead.
-hermesEnabled=true
-```
-
-:::note
-This property was added in React Native 0.71. If you can't find it in your `gradle.properties` file, please refer to the documentation for the corresponding React Native version you're using.
-:::
-
-Also, if you're using ProGuard, you will need to add these rules in `proguard-rules.pro` :
-
-```
--keep class com.facebook.hermes.unicode.** { *; }
--keep class com.facebook.jni.** { *; }
-```
-
-Next, if you've already built your app at least once, clean the build:
-
-```shell
-$ cd android && ./gradlew clean
-```
-
-That's it! You should now be able to develop and deploy your app as usual:
-
-<Tabs groupId="package-manager" queryString defaultValue={constants.defaultPackageManager} values={constants.packageManagers}>
-<TabItem value="npm">
-
-```shell
-npm run android
-```
-
-</TabItem>
-<TabItem value="yarn">
-
-```shell
-yarn android
-```
-
-</TabItem>
-</Tabs>
-
-### iOS
-
-Since React Native 0.64, Hermes also runs on iOS. To enable Hermes for iOS, edit your `ios/Podfile` file and make the change illustrated below:
-
-```diff
-   use_react_native!(
-     :path => config[:reactNativePath],
-     # to enable hermes on iOS, change `false` to `true` and then install pods
-     # By default, Hermes is disabled on Old Architecture, and enabled on New Architecture.
-     # You can enable/disable it manually by replacing `flags[:hermes_enabled]` with `true` or `false`.
--    :hermes_enabled => flags[:hermes_enabled],
-+    :hermes_enabled => true
-   )
-```
-
-By default, you will be using Hermes if you're on the New Architecture. By specifying a value such
-as `true` or `false` you can enable/disable Hermes as you wish.
-
-Once you've configured it, you can install the Hermes pods with:
-
-```shell
-$ cd ios && pod install
-```
-
-That's it! You should now be able to develop and deploy your app as usual:
-
-<Tabs groupId="package-manager" queryString defaultValue={constants.defaultPackageManager} values={constants.packageManagers}>
-<TabItem value="npm">
-
-```shell
-npm run ios
-```
-
-</TabItem>
-<TabItem value="yarn">
-
-```shell
-yarn ios
-```
-
-</TabItem>
-</Tabs>
+This will compile JavaScript to Hermes Bytecode during build time which will improve your app's startup speed on device.
 
 ## Switching back to JavaScriptCore
 
@@ -241,11 +110,6 @@ Edit your `ios/Podfile` file and make the change illustrated below:
    use_react_native!(
      :path => config[:reactNativePath],
 +    :hermes_enabled => false,
-     # Enables Flipper.
-     #
-     # Note that if you have use_frameworks! enabled, Flipper will not work and
-     # you should disable the next line.
-     :flipper_configuration => flipper_config,
      # An absolute path to your application root.
      :app_path => "#{Pod::Config.instance.installation_root}/.."
    )
