Applied PR rmbrone#45

Author: igorbedek

ios/Classes/SwiftFlutterAudioRecorderPlugin.swift

@@ -64,6 +64,13 @@ public class SwiftFlutterAudioRecorderPlugin: NSObject, FlutterPlugin, AVAudioRe
                 AVNumberOfChannelsKey: 1,
                 AVEncoderAudioQualityKey: AVAudioQuality.high.rawValue
             ]
+
+            guard let destinationUrl = URL(string: mPath) else {
+                let errorMessage = "Failed to initialize URL path from string: \(mPath)"
+                print(errorMessage)
+                result(FlutterError(code: "", message: errorMessage, details: error))
+                return
+            }
 
             do {
                 #if swift(>=4.2)
@@ -72,7 +79,7 @@ public class SwiftFlutterAudioRecorderPlugin: NSObject, FlutterPlugin, AVAudioRe
                 try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayAndRecord, with: AVAudioSessionCategoryOptions.defaultToSpeaker)
                 #endif
                 try AVAudioSession.sharedInstance().setActive(true)
-                audioRecorder = try AVAudioRecorder(url: URL(string: mPath)!, settings: settings)
+                audioRecorder = try AVAudioRecorder(url: destinationUrl, settings: settings)
                 audioRecorder.delegate = self
                 audioRecorder.isMeteringEnabled = true
                 audioRecorder.prepareToRecord()