Fix failing test and low android compileSdk

example/android/app/build.gradle

@@ -25,7 +25,7 @@ apply plugin: 'com.android.application'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
-    compileSdkVersion 30
+    compileSdkVersion 31
 
     defaultConfig {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).

example/lib/main.dart

@@ -46,7 +46,9 @@ class _MyAppState extends State<MyApp> {
               children: <Widget>[
                 Icon(
                   Icons.headset,
-                  color: this._headsetState == HeadsetState.CONNECT ? Colors.green : Colors.red,
+                  color: this._headsetState == HeadsetState.CONNECT
+                      ? Colors.green
+                      : Colors.red,
                 ),
                 Text('State : $_headsetState\n'),
               ],

example/pubspec.lock

@@ -7,7 +7,7 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.8.2"
+    version: "2.9.0"
   boolean_selector:
     dependency: transitive
     description:
@@ -21,21 +21,14 @@ packages:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
-  charcode:
-    dependency: transitive
-    description:
-      name: charcode
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.3.1"
+    version: "1.2.1"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.1.1"
   collection:
     dependency: transitive
     description:
@@ -56,7 +49,7 @@ packages:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0"
+    version: "1.3.1"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -80,28 +73,28 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.11"
+    version: "0.12.12"
   material_color_utilities:
     dependency: transitive
     description:
       name: material_color_utilities
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.4"
+    version: "0.1.5"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.7.0"
+    version: "1.8.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.1"
+    version: "1.8.2"
   permission_handler:
     dependency: transitive
     description:
@@ -155,7 +148,7 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.2"
+    version: "1.9.0"
   stack_trace:
     dependency: transitive
     description:
@@ -176,21 +169,21 @@ packages:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.1.1"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "1.2.1"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.4.9"
+    version: "0.4.12"
   vector_math:
     dependency: transitive
     description:

lib/headset_event.dart

@@ -32,7 +32,8 @@ class HeadsetEvent {
 
   factory HeadsetEvent() {
     if (_instance == null) {
-      final methodChannel = const MethodChannel('flutter.moum/headset_connection_event');
+      final methodChannel =
+          const MethodChannel('flutter.moum/headset_connection_event');
       _instance = HeadsetEvent.private(methodChannel);
     }
 
@@ -49,7 +50,7 @@ class HeadsetEvent {
       case 1:
         return HeadsetState.CONNECT;
       default:
-        return null;
+        return HeadsetState.DISCONNECT;
     }
   }
 

pubspec.lock

@@ -28,7 +28,7 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.8.2"
+    version: "2.9.0"
   boolean_selector:
     dependency: transitive
     description:
@@ -63,21 +63,14 @@ packages:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
-  charcode:
-    dependency: transitive
-    description:
-      name: charcode
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.3.1"
+    version: "1.2.1"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.1.1"
   code_builder:
     dependency: transitive
     description:
@@ -119,7 +112,7 @@ packages:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0"
+    version: "1.3.1"
   file:
     dependency: transitive
     description:
@@ -164,21 +157,21 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.11"
+    version: "0.12.12"
   material_color_utilities:
     dependency: transitive
     description:
       name: material_color_utilities
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.4"
+    version: "0.1.5"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.7.0"
+    version: "1.8.0"
   mockito:
     dependency: "direct dev"
     description:
@@ -199,7 +192,7 @@ packages:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.1"
+    version: "1.8.2"
   pedantic:
     dependency: transitive
     description:
@@ -274,7 +267,7 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.2"
+    version: "1.9.0"
   stack_trace:
     dependency: transitive
     description:
@@ -295,21 +288,21 @@ packages:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.1.1"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "1.2.1"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.4.9"
+    version: "0.4.12"
   typed_data:
     dependency: transitive
     description:

test/headset_connection_event_test.dart

@@ -5,25 +5,37 @@ import 'package:mockito/mockito.dart';
 
 typedef DetectPluggedCallback = Function(HeadsetState payload);
 
-class MockMethodChannel extends Mock implements MethodChannel {}
+class MockMethodChannel extends Mock implements MethodChannel {
+  @override
+  Future<T?> invokeMethod<T>(String method, [dynamic arguments]) {
+    return super.noSuchMethod(Invocation.getter(#invokeMethod),
+        returnValue: Future.value(0));
+  }
+}
 
 void main() {
   late final MockMethodChannel _methodChannel;
   late final HeadsetEvent _he;
 
   setUp(() {
+    print('setting up');
     _methodChannel = MockMethodChannel();
+    print('setting headset');
     _he = HeadsetEvent.private(_methodChannel);
   });
 
   test('getCurrentState', () async {
-    when(_methodChannel.invokeMethod<int>('getCurrentState')).thenAnswer((Invocation invoke) => Future<int>.value(0));
+    when(_methodChannel.invokeMethod<int>('getCurrentState'))
+        .thenAnswer((Invocation invoke) => Future<int?>.value(0));
+
     expect(await _he.getCurrentState, HeadsetState.DISCONNECT);
 
-    when(_methodChannel.invokeMethod<int>('getCurrentState')).thenAnswer((Invocation invoke) => Future<int>.value(1));
+    when(_methodChannel.invokeMethod<int>('getCurrentState'))
+        .thenAnswer((Invocation invoke) => Future<int>.value(1));
     expect(await _he.getCurrentState, HeadsetState.CONNECT);
 
-    when(_methodChannel.invokeMethod<int>('getCurrentState')).thenAnswer((Invocation invoke) => Future<int>.value(-1));
+    when(_methodChannel.invokeMethod<int>('getCurrentState'))
+        .thenAnswer((Invocation invoke) => Future<int>.value(-1));
     expect(await _he.getCurrentState, HeadsetState.DISCONNECT);
   });
 }