Improve native error handling (#10)

android/src/main/kotlin/com/navideck/universal_ble/UniversalBleHelper.kt

@@ -106,6 +106,33 @@ fun Int.parseBluetoothStatusCodeError(): String? {
     }
 }
 
+fun Int.parseGattErrorCode(): String? {
+    return when (this) {
+        BluetoothGatt.GATT_SUCCESS -> null
+        BluetoothGatt.GATT_READ_NOT_PERMITTED -> "GATT_READ_NOT_PERMITTED"
+        BluetoothGatt.GATT_WRITE_NOT_PERMITTED -> "GATT_WRITE_NOT_PERMITTED"
+        BluetoothGatt.GATT_INSUFFICIENT_AUTHENTICATION -> "GATT_INSUFFICIENT_AUTHENTICATION"
+        BluetoothGatt.GATT_REQUEST_NOT_SUPPORTED -> "GATT_REQUEST_NOT_SUPPORTED"
+        BluetoothGatt.GATT_INVALID_OFFSET -> "GATT_INVALID_OFFSET"
+        BluetoothGatt.GATT_INSUFFICIENT_AUTHORIZATION -> "GATT_INSUFFICIENT_AUTHORIZATION"
+        BluetoothGatt.GATT_INVALID_ATTRIBUTE_LENGTH -> "GATT_INVALID_ATTRIBUTE_LENGTH"
+        BluetoothGatt.GATT_INSUFFICIENT_ENCRYPTION -> "GATT_INSUFFICIENT_ENCRYPTION"
+        BluetoothGatt.GATT_CONNECTION_CONGESTED -> "GATT_CONNECTION_CONGESTED"
+        BluetoothGatt.GATT_FAILURE -> "GATT_FAILURE"
+        0x01 -> "GATT_INVALID_HANDLE"
+        0x04 -> "GATT_INVALID_PDU"
+        0x09 -> "GATT_PREPARE_QUEUE_FULL"
+        0x0a -> "GATT_ATTR_NOT_FOUND"
+        0x0b -> "GATT_ATTR_NOT_LONG"
+        0x0c -> "GATT_INSUFFICIENT_KEY_SIZE"
+        0x0e -> "GATT_UNLIKELY"
+        0x10 -> "GATT_UNSUPPORTED_GROUP"
+        0x11 -> "GATT_INSUFFICIENT_RESOURCES"
+        else -> "Unknown Error: $this"
+    }
+}
+
+
 val ScanResult.manufacturerDataHead: ByteArray?
     get() {
         val sparseArray = scanRecord?.manufacturerSpecificData ?: return null

android/src/main/kotlin/com/navideck/universal_ble/UniversalBlePlugin.kt

@@ -267,7 +267,20 @@ class UniversalBlePlugin : UniversalBlePlatformChannel, BluetoothGattCallback(),
                     it.serviceId == characteristic.service.uuid.toString()
         }.forEach {
             bleCharacteristicFutureList.remove(it)
-            it.result(Result.success(value))
+            if (status == BluetoothGatt.GATT_SUCCESS) {
+                it.result(Result.success(value))
+            } else {
+                it.result(
+                    Result.failure(
+                        FlutterError(
+                            status.toString(),
+                            "Failed to read: (${status.parseGattErrorCode()})",
+                            null,
+                        )
+                    )
+                )
+            }
+
         }
     }
 
@@ -374,9 +387,9 @@ class UniversalBlePlugin : UniversalBlePlatformChannel, BluetoothGattCallback(),
                 it.result(
                     Result.failure(
                         FlutterError(
-                            "Failed",
-                            "Failed to write ($status)",
-                            "status $status"
+                            status.toString(),
+                            "Failed to write: (${status.parseGattErrorCode()})",
+                            null,
                         )
                     )
                 )

darwin/Classes/UniversalBleHelper.swift

@@ -101,6 +101,15 @@ extension CBManagerState {
     }
 }
 
+extension Error {
+    func toFlutterError() -> FlutterError {
+        let nsError = self as NSError
+        let errorCode: String = .init(nsError.code)
+        let errorDescription: String = nsError.localizedDescription
+        return FlutterError(code: errorCode, message: errorDescription, details: nil)
+    }
+}
+
 public extension CBUUID {
     var uuidStr: String {
         uuidString.lowercased()

darwin/Classes/UniversalBlePlugin.swift

@@ -36,7 +36,7 @@ private class BleCentralDarwin: NSObject, UniversalBlePlatformChannel, CBCentral
       oldValue?(Result.success(AvailabilityState.unknown.rawValue))
     }
   }
-  
+
   init(callbackChannel: UniversalBleCallbackChannel) {
     self.callbackChannel = callbackChannel
     super.init()
@@ -44,14 +44,14 @@ private class BleCentralDarwin: NSObject, UniversalBlePlatformChannel, CBCentral
 
   func getBluetoothAvailabilityState(completion: @escaping (Result<Int64, Error>) -> Void) {
     let managerState = manager.state
-    
+
     if managerState == .unknown {
       bluetoothAvailabilityStateCallback = completion
     } else {
       completion(.success(managerState.toAvailabilityState().rawValue))
     }
   }
-    
+
   func enableBluetooth(completion: @escaping (Result<Bool, Error>) -> Void) {
     completion(Result.failure(FlutterError(code: "NotSupported", message: nil, details: nil)))
   }
@@ -280,8 +280,8 @@ private class BleCentralDarwin: NSObject, UniversalBlePlatformChannel, CBCentral
     // Update futures for writeValue
     characteristicWriteFutures.removeAll { future in
       if future.deviceId == peripheral.uuid.uuidString && future.characteristicId == characteristic.uuid.uuidStr && future.serviceId == characteristic.service?.uuid.uuidStr {
-        if error != nil {
-          future.result(Result.failure(FlutterError(code: "WriteFailed", message: String(describing: error), details: nil)))
+        if let flutterError = error?.toFlutterError() {
+          future.result(Result.failure(flutterError))
         } else {
           future.result(Result.success({}()))
         }
@@ -306,8 +306,8 @@ private class BleCentralDarwin: NSObject, UniversalBlePlatformChannel, CBCentral
     // Update futures for readValue
     characteristicReadFutures.removeAll { future in
       if future.deviceId == peripheral.uuid.uuidString && future.characteristicId == characteristic.uuid.uuidStr && future.serviceId == characteristic.service?.uuid.uuidStr {
-        if error != nil {
-          future.result(Result.failure(FlutterError(code: "ReadFailed", message: String(describing: error), details: nil)))
+        if let flutterError = error?.toFlutterError() {
+          future.result(Result.failure(flutterError))
         } else {
           if let characteristicValue = characteristic.value {
             future.result(Result.success(FlutterStandardTypedData(bytes: characteristicValue)))

example/pubspec.lock

@@ -386,7 +386,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "0.9.0"
+    version: "0.9.1"
   vector_math:
     dependency: transitive
     description: