improve error logging

packages/flutter_mozilla_components/android/src/main/assets/extensions/ml_engine/background.js

@@ -15,10 +15,14 @@ function sendJsonResultForRequest(id) {
 function sendErrorForRequest(id) {
     return function (error) {
         console.error(error);
+        const message = error?.message || String(error);
         port.postMessage({
             "id": id,
             "status": "error",
-            "error": error?.message || String(error)
+            "error": message,
+            "errorName": error?.name,
+            "errorStack": error?.stack,
+            "errorString": String(error)
         });
     }
 }

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/feature/MLEngineFeature.kt

@@ -114,10 +114,23 @@ object MLEngineFeature {
                         if (status == "success") {
                             handler?.success(message)
                         } else {
+                            val errorDetails = buildString {
+                                append(messageJSON.optString("error", "Unknown ML engine error"))
+                                messageJSON.optString("errorName").takeIf { it.isNotBlank() }?.let {
+                                    append("\nName: ").append(it)
+                                }
+                                messageJSON.optString("errorString").takeIf { it.isNotBlank() }?.let {
+                                    append("\nString: ").append(it)
+                                }
+                                messageJSON.optString("errorStack").takeIf { it.isNotBlank() }?.let {
+                                    append("\nStack: ").append(it)
+                                }
+                            }
+
                             handler?.error(
                                 "ML Engine",
                                 "Failed to perform operation",
-                                messageJSON.optString("error", "Unknown ML engine error")
+                                errorDetails
                             )
                         }
                     }