Exception fixes.

src/Squidex.Infrastructure/Commands/DomainObjectGrain.cs

@@ -14,6 +14,7 @@ using Orleans.Runtime;
 using Squidex.Infrastructure.EventSourcing;
 using Squidex.Infrastructure.Orleans;
 using Squidex.Infrastructure.States;
+using Squidex.Infrastructure.Tasks;
 
 namespace Squidex.Infrastructure.Commands
 {
@@ -108,17 +109,17 @@ namespace Squidex.Infrastructure.Commands
 
         protected Task<object> CreateReturnAsync<TCommand>(TCommand command, Func<TCommand, object> handler) where TCommand : class, IAggregateCommand
         {
-            return InvokeAsync(command, x => Task.FromResult(handler(x)), false);
+            return InvokeAsync(command, handler?.ToAsync(), false);
         }
 
         protected Task<object> CreateAsync<TCommand>(TCommand command, Func<TCommand, Task> handler) where TCommand : class, IAggregateCommand
         {
-            return InvokeAsync(command, x => handler(x).ContinueWith<object>(t => null), false);
+            return InvokeAsync(command, handler.ToDefault<TCommand, object>(), false);
         }
 
         protected Task<object> CreateAsync<TCommand>(TCommand command, Action<TCommand> handler) where TCommand : class, IAggregateCommand
         {
-            return InvokeAsync(command, x => { handler(x); return Task.FromResult<object>(null); }, false);
+            return InvokeAsync(command, handler?.ToDefault<TCommand, object>()?.ToAsync(), false);
         }
 
         protected Task<object> UpdateReturnAsync<TCommand>(TCommand command, Func<TCommand, Task<object>> handler) where TCommand : class, IAggregateCommand
@@ -128,17 +129,17 @@ namespace Squidex.Infrastructure.Commands
 
         protected Task<object> UpdateReturnAsync<TCommand>(TCommand command, Func<TCommand, object> handler) where TCommand : class, IAggregateCommand
         {
-            return InvokeAsync(command, x => Task.FromResult(handler(x)), true);
+            return InvokeAsync(command, handler?.ToAsync(), true);
         }
 
         protected Task<object> UpdateAsync<TCommand>(TCommand command, Func<TCommand, Task> handler) where TCommand : class, IAggregateCommand
         {
-            return InvokeAsync(command, x => handler(x).ContinueWith<object>(t => null), true);
+            return InvokeAsync(command, handler?.ToDefault<TCommand, object>(), true);
         }
 
         protected Task<object> UpdateAsync<TCommand>(TCommand command, Action<TCommand> handler) where TCommand : class, IAggregateCommand
         {
-            return InvokeAsync(command, x => { handler(x); return Task.FromResult<object>(null); }, true);
+            return InvokeAsync(command, handler?.ToDefault<TCommand, object>()?.ToAsync(), true);
         }
 
         private async Task<object> InvokeAsync<TCommand>(TCommand command, Func<TCommand, Task<object>> handler, bool isUpdate) where TCommand : class, IAggregateCommand

src/Squidex.Infrastructure/Tasks/PartitionedActionBlock.cs

@@ -24,7 +24,7 @@ namespace Squidex.Infrastructure.Tasks
         }
 
         public PartitionedActionBlock(Action<TInput> action, Func<TInput, int> partitioner)
-            : this (ToAsync(action), partitioner, new ExecutionDataflowBlockOptions())
+            : this (action?.ToAsync(), partitioner, new ExecutionDataflowBlockOptions())
         {
         }
 
@@ -34,7 +34,7 @@ namespace Squidex.Infrastructure.Tasks
         }
 
         public PartitionedActionBlock(Action<TInput> action, Func<TInput, int> partitioner, ExecutionDataflowBlockOptions dataflowBlockOptions)
-            : this(ToAsync(action), partitioner, dataflowBlockOptions)
+            : this(action?.ToAsync(), partitioner, dataflowBlockOptions)
         {
         }
 
@@ -94,17 +94,5 @@ namespace Squidex.Infrastructure.Tasks
         {
             distributor.Fault(exception);
         }
-
-        private static Func<TInput, Task> ToAsync(Action<TInput> action)
-        {
-            Guard.NotNull(action, nameof(action));
-
-            return x =>
-            {
-                action(x);
-
-                return TaskHelper.Done;
-            };
-        }
     }
 }

src/Squidex.Infrastructure/Tasks/TaskExtensions.cs

@@ -16,7 +16,43 @@ namespace Squidex.Infrastructure.Tasks
         {
         }
 
-        public static Func<T, Task> ToAsync<T>(this Action<T> action)
+        public static Func<TInput, TOutput> ToDefault<TInput, TOutput>(this Action<TInput> action)
+        {
+            Guard.NotNull(action, nameof(action));
+
+            return x =>
+            {
+                action(x);
+
+                return default(TOutput);
+            };
+        }
+
+        public static Func<TInput, Task<TOutput>> ToDefault<TInput, TOutput>(this Func<TInput, Task> action)
+        {
+            Guard.NotNull(action, nameof(action));
+
+            return async x =>
+            {
+                await action(x);
+
+                return default(TOutput);
+            };
+        }
+
+        public static Func<TInput, Task<TOutput>> ToAsync<TInput, TOutput>(this Func<TInput, TOutput> action)
+        {
+            Guard.NotNull(action, nameof(action));
+
+            return x =>
+            {
+                var result = action(x);
+
+                return Task.FromResult(result);
+            };
+        }
+
+        public static Func<TInput, Task> ToAsync<TInput>(this Action<TInput> action)
         {
             return x =>
             {