add websocket_test.dart

packages/stream_chat/lib/src/core/api/responses.dart

@@ -18,7 +18,7 @@ class _BaseResponse {
 }
 
 /// Model response for [StreamChatNetworkError] data
-@JsonSerializable(createToJson: false)
+@JsonSerializable()
 class ErrorResponse extends _BaseResponse {
   ///
   int? code;
@@ -37,6 +37,9 @@ class ErrorResponse extends _BaseResponse {
   static ErrorResponse fromJson(Map<String, dynamic> json) =>
       _$ErrorResponseFromJson(json);
 
+  /// Serialize to json
+  Map<String, dynamic> toJson() => _$ErrorResponseToJson(this);
+
   @override
   String toString() => 'ErrorResponse(code: $code, '
       'message: $message, '

packages/stream_chat/lib/src/core/api/responses.g.dart

@@ -15,6 +15,15 @@ ErrorResponse _$ErrorResponseFromJson(Map<String, dynamic> json) {
     ..moreInfo = json['more_info'] as String?;
 }
 
+Map<String, dynamic> _$ErrorResponseToJson(ErrorResponse instance) =>
+    <String, dynamic>{
+      'duration': instance.duration,
+      'code': instance.code,
+      'message': instance.message,
+      'StatusCode': instance.statusCode,
+      'more_info': instance.moreInfo,
+    };
+
 SyncResponse _$SyncResponseFromJson(Map<String, dynamic> json) {
   return SyncResponse()
     ..duration = json['duration'] as String?