Nullable refernce types refactoring

WotBlitzStatisticsPro.Logic/Pipeline/IOperation.cs

@@ -13,6 +13,6 @@ namespace WotBlitzStatisticsPro.Logic.Pipeline
         /// </summary>
         /// <param name="context">Pipeline context</param>
         /// <param name="next">Next operation</param>
-        Task Invoke(TContext context, Func<TContext, Task> next);
+        Task Invoke(TContext context, Func<TContext, Task>? next);
     }
 }

WotBlitzStatisticsPro.Logic/Pipeline/IPipeline.cs

@@ -9,7 +9,7 @@
         /// Builds the pipeline.
         /// </summary>
         /// <returns>First operation in pipeline.</returns>
-        IOperation<TContext> Build();
+        IOperation<TContext>? Build();
 
         /// <summary>
         /// Adds operation type to the pipeline

WotBlitzStatisticsPro.Logic/Pipeline/OperationMediator.cs

@@ -6,15 +6,15 @@ namespace WotBlitzStatisticsPro.Logic.Pipeline
     public class OperationMediator<TContext>: IOperation<TContext>
     {
         private readonly IOperation<TContext> _current;
-        private readonly IOperation<TContext> _next;
+        private readonly IOperation<TContext>? _next;
 
-        public OperationMediator(IOperation<TContext> current, IOperation<TContext> next)
+        public OperationMediator(IOperation<TContext> current, IOperation<TContext>? next)
         {
             _current = current ?? throw new ArgumentNullException(nameof(current));
             _next = next;
         }
 
-        public Task Invoke(TContext context, Func<TContext, Task> next)
+        public Task Invoke(TContext context, Func<TContext, Task>? next)
         {
             return _current.Invoke(context, c => _next == null ? Task.CompletedTask : _next.Invoke(c, null));
         }

WotBlitzStatisticsPro.Logic/Pipeline/Pipeline.cs

@@ -14,7 +14,7 @@ namespace WotBlitzStatisticsPro.Logic.Pipeline
             _operationFactory = operationFactory;
         }
 
-        public IOperation<TContext> Build()
+        public IOperation<TContext>? Build()
         {
             var allOperationTypes = _operations.ToArray();
             var lastOperationType = allOperationTypes.LastOrDefault();

WotBlitzStatisticsPro.Logic/Pipeline/ServiceProviderOperationFactory.cs

@@ -13,7 +13,7 @@ namespace WotBlitzStatisticsPro.Logic.Pipeline
 
         public IOperation<TContext> Create<TContext>(Type operationType)
         {
-            return _serviceProvider.GetService(operationType) as IOperation<TContext>;
+            return (_serviceProvider.GetService(operationType) as IOperation<TContext>)!;
         }
     }
 }