allow null value in requests

Author: Reza-deriv

lib/services/connection/api_manager/base_api.dart

@@ -33,7 +33,7 @@ abstract class BaseAPI {
   void addToChannel(Map<String, dynamic> request);
 
   /// Calls a API method by [request].
-  Future<T> call<T>({required Request request});
+  Future<T> call<T>({required Request request, bool acceptNullValue = false});
 
   /// Subscribe to a [request].
   /// [comparePredicate] indicates compare condition for current [request] and [pendingRequest]s

lib/services/connection/api_manager/binary_api.dart

@@ -139,7 +139,8 @@ class BinaryAPI extends BaseAPI {
   }
 
   @override
-  Future<T> call<T>({required Request request}) async {
+  Future<T> call<T>(
+      {required Request request, bool acceptNullValue = false}) async {
     final Response response = await (_callManager ??= CallManager(this))(
       request: request,
     );

lib/services/connection/api_manager/mock_api.dart

@@ -130,7 +130,7 @@ class MockAPI extends BaseAPI {
   void addToChannel(Map<String, dynamic> request) {}
 
   @override
-  Future<T> call<T>({required Request request}) =>
+  Future<T> call<T>({required Request request, bool acceptNullValue = false}) =>
       _getFutureResponse<T>(request);
 
   @override

lib/services/connection/call_manager/base_call_manager.dart

@@ -43,7 +43,7 @@ abstract class BaseCallManager<T> {
   bool contains(int? requestId) => _pendingRequests.containsKey(requestId);
 
   /// Calls a API method by [request]
-  T call({required Request request});
+  T call({required Request request, bool acceptNullValue = false});
 
   /// Handle call [response] that comes from server
   void handleResponse({
@@ -62,12 +62,14 @@ abstract class BaseCallManager<T> {
   Future<Response> addToChannel({
     required Request request,
     SubscriptionStream<Response>? subscriptionStream,
+    bool acceptNullValue = false,
   }) {
     final Completer<Response> responseCompleter = Completer<Response>();
     final Request requestWithId = request.copyWith(reqId: _getRequestId());
     final Map<String, dynamic> prepareRequest = _prepareRequest(
       request: requestWithId,
       isSubscription: subscriptionStream != null,
+      acceptNullValue: acceptNullValue,
     );
 
     _addPendingRequest(
@@ -104,6 +106,7 @@ abstract class BaseCallManager<T> {
   Map<String, dynamic> _prepareRequest({
     required Request request,
     required bool isSubscription,
+    bool acceptNullValue = false,
   }) {
     final Map<String, dynamic> result = request.toJson()
       ..removeWhere((String key, dynamic value) => value == null);

lib/services/connection/call_manager/call_manager.dart

@@ -29,6 +29,7 @@ class CallManager extends BaseCallManager<Future<Response>> {
   }
 
   @override
-  Future<Response> call({required Request request}) async =>
-      addToChannel(request: request);
+  Future<Response> call(
+          {required Request request, bool acceptNullValue = false}) async =>
+      addToChannel(request: request, acceptNullValue: acceptNullValue);
 }

lib/services/connection/call_manager/subscription_manager.dart

@@ -51,11 +51,11 @@ class SubscriptionManager extends BaseCallManager<Stream<Response>> {
   }
 
   @override
-  Stream<Response> call({
-    required Request request,
-    int cacheSize = 0,
-    RequestCompareFunction? comparePredicate,
-  }) {
+  Stream<Response> call(
+      {required Request request,
+      int cacheSize = 0,
+      RequestCompareFunction? comparePredicate,
+      bool acceptNullValue = false}) {
     assert(cacheSize >= 0);
 
     final PendingRequest<Response>? pendingRequest = _getPendingRequest(
@@ -78,6 +78,7 @@ class SubscriptionManager extends BaseCallManager<Stream<Response>> {
     addToChannel(
       request: request,
       subscriptionStream: subscriptionStream,
+      acceptNullValue: acceptNullValue,
     );
 
     return subscriptionStream.stream;

test/services/call_manager/base_call_manager_test.dart

@@ -50,7 +50,7 @@ class MockCallManager extends BaseCallManager<MockResponse> {
   MockCallManager(BaseAPI api) : super(api);
 
   @override
-  MockResponse call({required Request request}) {
+  MockResponse call({required Request request, bool acceptNullValue = false}) {
     throw UnimplementedError();
   }
 }
@@ -60,7 +60,8 @@ class MockAPI implements BaseAPI {
   void addToChannel(Map<String, dynamic> request) {}
 
   @override
-  Future<T> call<T>({required Request request}) => throw UnimplementedError();
+  Future<T> call<T>({required Request request, bool acceptNullValue = false}) =>
+      throw UnimplementedError();
 
   @override
   Future<void> connect(