fix(CLI): ensure backward compatibility of hermes compile process

Author: floydkim

cli/functions/runHermesEmitBinaryCommand.ts

@@ -114,22 +114,10 @@ function getHermesCommand(): string {
             return false;
         }
     };
-    const reactNativePath = getReactNativePackagePath();
-    const hermesCompilerPath = getHermesCompilerPackagePath();
-
-    // Since react-native 0.83, Hermes compiler in 'hermes-compiler' package
-    if (hermesCompilerPath) {
-        const engine = path.join(hermesCompilerPath, 'hermesc', getHermesOSBin(), getHermesOSExe());
-        if (fileExists(engine)) {
-            return engine;
-        }
-    }
 
-    // Hermes is bundled with react-native since 0.69
-    const bundledHermesEngine = path.join(reactNativePath, 'sdks', 'hermesc', getHermesOSBin(), getHermesOSExe());
-    // Hermes is bundled with react-native since 0.69
-    if (fileExists(bundledHermesEngine)) {
-        return bundledHermesEngine;
+    const hermescExecutable = path.join(getHermesCompilerPath(), getHermesOSBin(), getHermesOSExe());
+    if (fileExists(hermescExecutable)) {
+        return hermescExecutable;
     }
     throw new Error('Hermes engine binary not found. Please upgrade to react-native 0.69 or later');
 }
@@ -180,19 +168,26 @@ function getReactNativePackagePath(): string {
     return path.join('node_modules', 'react-native');
 }
 
-function getHermesCompilerPackagePath() {
-    try {
-        const result = childProcess.spawnSync('node', [
-            '--print',
-            "require.resolve('hermes-compiler/package.json')",
-        ]);
-        const packagePath = path.dirname(result.stdout.toString());
-        if (result.status === 0 && directoryExistsSync(packagePath)) {
-            return packagePath;
-        }
-        return path.join('node_modules', 'hermes-compiler');
-    } catch {
-        return null;
+function getHermescDirPathInHermesCompilerPackage() {
+    const result = childProcess.spawnSync('node', [
+        '--print',
+        "require.resolve('hermes-compiler/package.json')",
+    ]);
+    const packagePath = path.dirname(result.stdout.toString());
+    const hermescDirPath = path.join(packagePath, 'hermesc');
+    if (result.status === 0 && directoryExistsSync(hermescDirPath)) {
+        return hermescDirPath;
+    }
+    return null;
+}
+
+function getHermesCompilerPath() {
+    const hermescDirPath = getHermescDirPathInHermesCompilerPackage();
+    if (hermescDirPath) {
+        // Since react-native 0.83, Hermes compiler executables are in 'hermes-compiler' package
+        return hermescDirPath
+    } else {
+        return path.join(getReactNativePackagePath(), 'sdks', 'hermesc');
     }
 }