Added pedantic lib for better static analysis (#494)

* Added pedantic lib for better static analysis

Fixed (what I hope) are the biggest static analysis issues on pub.dev.

* Fixed device_connection_mixin.

* Code review updates.

* Format fix.

Author: dariuszseweryn

analysis_options.yaml

@@ -0,0 +1 @@
+include: package:pedantic/analysis_options.yaml

lib/ble_manager.dart

@@ -34,9 +34,7 @@ abstract class BleManager {
   static BleManager _instance;
 
   factory BleManager() {
-    if (_instance == null) {
-      _instance = InternalBleManager();
-    }
+    _instance ??= InternalBleManager();
 
     return _instance;
   }

lib/peripheral.dart

@@ -15,7 +15,7 @@ abstract class _PeripheralMetadata {
 /// [disconnectOrCancelConnection()] can be used if peripheral is not connected.
 class Peripheral {
   static const int NO_MTU_NEGOTIATION = 0;
-  ManagerForPeripheral _manager;
+  final ManagerForPeripheral _manager;
 
   String name;
   String identifier;

lib/scan_result.dart

@@ -1,8 +1,6 @@
 part of flutter_ble_lib;
 
 abstract class _ScanResultMetadata {
-  static const String id = "id";
-  static const String name = "name";
   static const String rssi = "rssi";
   static const String manufacturerData = "manufacturerData";
   static const String serviceData = "serviceData";

lib/src/bridge/device_connection_mixin.dart

@@ -7,20 +7,41 @@ mixin DeviceConnectionMixin on FlutterBLE {
 
   Future<void> connectToPeripheral(String deviceIdentifier, bool isAutoConnect,
       int requestMtu, bool refreshGatt, Duration timeout) async {
-    return await _methodChannel
-        .invokeMethod(MethodName.connectToDevice, <String, dynamic>{
-      ArgumentName.deviceIdentifier: deviceIdentifier,
-      ArgumentName.isAutoConnect: isAutoConnect,
-      ArgumentName.requestMtu: requestMtu,
-      ArgumentName.refreshGatt: refreshGatt,
-      ArgumentName.timeoutMillis: timeout?.inMilliseconds
-    }).catchError((errorJson) =>
-            Future.error(BleError.fromJson(jsonDecode(errorJson.details))));
+    return await _methodChannel.invokeMethod(
+      MethodName.connectToDevice,
+      <String, dynamic>{
+        ArgumentName.deviceIdentifier: deviceIdentifier,
+        ArgumentName.isAutoConnect: isAutoConnect,
+        ArgumentName.requestMtu: requestMtu,
+        ArgumentName.refreshGatt: refreshGatt,
+        ArgumentName.timeoutMillis: timeout?.inMilliseconds
+      },
+    ).catchError(
+      (errorJson) => Future.error(
+        BleError.fromJson(jsonDecode(errorJson.details)),
+      ),
+    );
   }
 
   Stream<PeripheralConnectionState> observePeripheralConnectionState(
-      String identifier, bool emitCurrentValue) async* {
-    yield* _peripheralConnectionStateChanges
+      String identifier, bool emitCurrentValue) {
+    var controller = StreamController<String>(
+      onListen: () => _methodChannel.invokeMethod(
+        MethodName.observeConnectionState,
+        <String, dynamic>{
+          ArgumentName.deviceIdentifier: identifier,
+          ArgumentName.emitCurrentValue: emitCurrentValue,
+        },
+      ).catchError(
+        (errorJson) => throw BleError.fromJson(jsonDecode(errorJson.details)),
+      ),
+    );
+
+    controller
+        .addStream(_peripheralConnectionStateChanges)
+        .then((value) => controller?.close());
+
+    return controller.stream
         .map((jsonString) =>
             ConnectionStateContainer.fromJson(jsonDecode(jsonString)))
         .where((connectionStateContainer) =>
@@ -39,32 +60,32 @@ mixin DeviceConnectionMixin on FlutterBLE {
           return PeripheralConnectionState.disconnecting;
         default:
           throw FormatException(
-              "Unrecognized value of device connection state. Value: $connectionStateString");
+            'Unrecognized value of device connection state. Value: $connectionStateString',
+          );
       }
     });
-
-    _methodChannel.invokeMethod(
-        MethodName.observeConnectionState, <String, dynamic>{
-      ArgumentName.deviceIdentifier: identifier,
-      ArgumentName.emitCurrentValue: emitCurrentValue,
-    }).catchError(
-        (errorJson) => throw BleError.fromJson(jsonDecode(errorJson.details)));
   }
 
   Future<bool> isPeripheralConnected(String peripheralIdentifier) async {
     return await _methodChannel
         .invokeMethod(MethodName.isDeviceConnected, <String, dynamic>{
       ArgumentName.deviceIdentifier: peripheralIdentifier,
-    }).catchError((errorJson) =>
-            Future.error(BleError.fromJson(jsonDecode(errorJson.details))));
+    }).catchError(
+      (errorJson) => Future.error(
+        BleError.fromJson(jsonDecode(errorJson.details)),
+      ),
+    );
   }
 
   Future<void> disconnectOrCancelPeripheralConnection(
       String peripheralIdentifier) async {
     return await _methodChannel
         .invokeMethod(MethodName.cancelConnection, <String, dynamic>{
       ArgumentName.deviceIdentifier: peripheralIdentifier,
-    }).catchError((errorJson) =>
-            Future.error(BleError.fromJson(jsonDecode(errorJson.details))));
+    }).catchError(
+      (errorJson) => Future.error(
+        BleError.fromJson(jsonDecode(errorJson.details)),
+      ),
+    );
   }
 }

pubspec.yaml

@@ -17,6 +17,7 @@ dependencies:
 dev_dependencies:
   test: ^1.5.3
   mockito: ^4.0.0
+  pedantic: ^1.9.0
 
   flutter_test:
     sdk: flutter