Check if the supported version (10e) of Android NDK is installed

scripts/check-environment.js

@@ -54,6 +54,29 @@ exec('npm --version', (err, stdout) => {
   validateEnvPath('REALM_CORE_PREFIX');
   validateEnvPath('REALM_SYNC_PREFIX');
 
-  // TODO: Check ANDROID_NDK and SDK for Android, and XCode for iOS.
+  // Check ANDROID_NDK version
+  exec('which ndk-build', (err, stdout) => {
+    if(err) {
+      console.error("Android NDK (ndk-build) not found");
+      console.error(err.message);
+      process.exit(-1);
+    }
+
+    const ndkBuildPath = stdout.trim();
+    const ndkDirPath = path.dirname(ndkBuildPath);
+    const releaseTxtPath = path.join(ndkDirPath, "RELEASE.TXT");
+
+    exec(`grep ^r10e ${releaseTxtPath}`, (err, stdout) => {
+      if(err) {
+        // RELEASE.TXT doesn't exist or version mismatch
+        console.error("Incompatible Android NDK version found. NDK 10e is required.")
+        process.exit(-1);
+      }
+
+      successLog('Android NDK 10e found');
+    });
+  });
+
+  // TODO: Check SDK for Android, and XCode for iOS.
   
 });