Merge pull request #78 from react-native-community/fix/global-error

Fix issue with global.HermesIternal

README.md

@@ -25,12 +25,18 @@
 
 ## :arrow_forward: Usage
 
-> `react-native@0.60` or higher
+> `react-native@0.61.0` or higher
 
 ```sh
 npx react-native init MyApp --template react-native-template-typescript
 ```
 
+> `react-native@0.60.x`
+
+```sh
+npx react-native init MyApp --template react-native-template-typescript@6.2.0
+```
+
 ### Note on the legacy CLI
 There seems to be quite some confusion about the legacy CLI. This template only works with the new CLI. Make sure you have uninstalled the legacy `react-native-cli` first (`npm uninstall -g react-native-cli`), for the above command to work. If you wish to not use `npx`, you can also install the new CLI globally (`npm i -g @react-native-community/cli` or `yarn global add @react-native-community/cli`).
 

template/App.tsx

@@ -27,6 +27,7 @@ import {
 } from 'react-native/Libraries/NewAppScreen';
 
 const App = () => {
+  const usingHermes = typeof HermesInternal === 'object' && HermesInternal !== null;
   return (
     <>
       <StatusBar barStyle="dark-content" />
@@ -35,7 +36,7 @@ const App = () => {
           contentInsetAdjustmentBehavior="automatic"
           style={styles.scrollView}>
           <Header />
-          {global.HermesInternal == null ? null : (
+          {!usingHermes ? null : (
             <View style={styles.engine}>
               <Text style={styles.footer}>Engine: Hermes</Text>
             </View>