Fix crash in getAudioOutput

ios/RNCallKeep/RNCallKeep.m

@@ -131,12 +131,12 @@ - (void)startObserving
 - (void)stopObserving
 {
     _hasListeners = FALSE;
-    
+
     // Fix for https://github.com/react-native-webrtc/react-native-callkeep/issues/406
     // We use Objective-C Key Value Coding(KVC) to sync _RTCEventEmitter_ `_listenerCount`.
     @try {
         [self setValue:@0 forKey:@"_listenerCount"];
-    } 
+    }
     @catch ( NSException *e ){
         NSLog(@"[RNCallKeep][stopObserving] exception: %@",e);
         NSLog(@"[RNCallKeep][stopObserving] RNCallKeep parent class RTCEventEmitter might have a broken state.");
@@ -189,7 +189,16 @@ + (void)initCallKitProvider {
 }
 
 + (NSString *) getAudioOutput {
-    return [AVAudioSession sharedInstance].currentRoute.outputs.count > 0 ? [AVAudioSession sharedInstance].currentRoute.outputs[0].portType : nil;
+    @try{
+        NSArray<AVAudioSessionPortDescription *>* outputs = [AVAudioSession sharedInstance].currentRoute.outputs;
+        if(outputs != nil && outputs.count > 0){
+            return outputs[0].portType;
+        }
+    } @catch(NSException* error) {
+        NSLog(@"getAudioOutput error :%@", [error description]);
+    }
+
+    return nil;
 }
 
 + (void)setup:(NSDictionary *)options {
@@ -554,7 +563,7 @@ + (NSMutableArray *) formatAudioInputs: (NSMutableArray *)inputs
 {
     NSMutableArray *newInputs = [NSMutableArray new];
     NSString * selected = [RNCallKeep getSelectedAudioRoute];
-    
+
     NSMutableDictionary *speakerDict = [[NSMutableDictionary alloc]init];
     [speakerDict setObject:@"Speaker" forKey:@"name"];
     [speakerDict setObject:AVAudioSessionPortBuiltInSpeaker forKey:@"type"];
@@ -645,13 +654,13 @@ + (NSString *) getSelectedAudioRoute
     AVAudioSession* myAudioSession = [AVAudioSession sharedInstance];
     AVAudioSessionRouteDescription *currentRoute = [myAudioSession currentRoute];
     NSArray *selectedOutputs = currentRoute.outputs;
-    
+
     AVAudioSessionPortDescription *selectedOutput = selectedOutputs[0];
-    
+
     if(selectedOutput && [selectedOutput.portType isEqualToString:AVAudioSessionPortBuiltInReceiver]) {
         return @"Phone";
     }
-    
+
     return [RNCallKeep getAudioInputType: selectedOutput.portType];
 }
 
@@ -909,7 +918,7 @@ - (void)configureAudioSession
 
     NSUInteger categoryOptions = AVAudioSessionCategoryOptionAllowBluetooth | AVAudioSessionCategoryOptionAllowBluetoothA2DP;
     NSString *mode = AVAudioSessionModeDefault;
-    
+
     NSDictionary *settings = [RNCallKeep getSettings];
     if (settings && settings[@"audioSession"]) {
         if (settings[@"audioSession"][@"categoryOptions"]) {
@@ -920,7 +929,7 @@ - (void)configureAudioSession
             mode = settings[@"audioSession"][@"mode"];
         }
     }
-    
+
     AVAudioSession* audioSession = [AVAudioSession sharedInstance];
     [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord withOptions:categoryOptions error:nil];