Allow apple to configure Hermes as option (#44461)

Summary:
Pull Request resolved: #44461

Users would have to do this by manipulating the environment before.

Changelog: [Internal]

Reviewed By: cipolleschi

Differential Revision: D57067036

fbshipit-source-id: 6df16c884412578c3b5cae50e26ca37636a7dc5b

packages/core-cli-utils/src/private/apple.js

@@ -30,6 +30,7 @@ type AppleBuildOptions = {
 
 type AppleBootstrapOption = {
   // Enabled by default
+  hermes: boolean,
   newArchitecture: boolean,
   ...AppleOptions,
 };
@@ -75,12 +76,16 @@ export const tasks = {
         cwd: options.cwd,
       }),
     ),
-    installDependencies: task(THIRD, 'Install CocoaPods dependencies', () =>
-      execa('bundle', ['exec', 'pod', 'install'], {
+    installDependencies: task(THIRD, 'Install CocoaPods dependencies', () => {
+      const env = {
+        RCT_NEW_ARCH_ENABLED: options.newArchitecture ? '1' : '0',
+        HERMES: options.hermes ? '1' : '0',
+      };
+      return execa('bundle', ['exec', 'pod', 'install'], {
         cwd: options.cwd,
-        env: {RCT_NEW_ARCH_ENABLED: options.newArchitecture ? '1' : '0'},
-      }),
-    ),
+        env,
+      });
+    }),
   }),
 
   // 2. Build the iOS app using a setup environment

packages/helloworld/cli.flow.js

@@ -197,12 +197,14 @@ function run(
 bootstrap
   .command('ios')
   .description('Bootstrap iOS')
+  .option('--hermes', 'Enable Hermes', true)
   .option('--new-architecture', 'Enable new architecture', true)
-  .action(async (_, options: {newArchitecture: boolean}) => {
+  .action(async (_, options: {newArchitecture: boolean, hermes: boolean}) => {
     await run(
       apple.bootstrap({
-        newArchitecture: options.newArchitecture,
         cwd: cwd.ios,
+        hermes: options.hermes,
+        newArchitecture: options.newArchitecture,
       }),
     );
   });