Improve status messages

src/contrib/persistence/Akka.Persistence.Sql.Common/Snapshot/SqlSnapshotStore.cs

@@ -123,23 +123,27 @@ private async Task<object> Initialize()
             }
             catch (Exception e)
             {
-                return new Failure {Exception = e};
+                return new Status.Failure(e);
             }
         }
 
-        private bool WaitingForInitialization(object message) => message.Match()
-            .With<Initialized>(_ =>
-            {
-                UnbecomeStacked();
-                Stash.UnstashAll();
-            })
-            .With<Failure>(failure =>
+        private bool WaitingForInitialization(object message)
+        {
+            switch(message)
             {
-                Log.Error(failure.Exception, "Error during snapshot store initialization");
-                Context.Stop(Self);
-            })
-            .Default(_ => Stash.Stash())
-            .WasHandled;
+                case Initialized _:
+                    UnbecomeStacked();
+                    Stash.UnstashAll();
+                    return true;
+                case Status.Failure msg:
+                    Log.Error(msg.Cause, "Error during snapshot store initialization");
+                    Context.Stop(Self);
+                    return true;
+                default:
+                    Stash.Stash();
+                    return true;
+            }
+        }
 
         /// <summary>
         /// TBD

src/core/Akka.API.Tests/CoreAPISpec.ApproveCore.approved.txt

@@ -853,12 +853,14 @@ namespace Akka.Actor
         }
         public delegate void TransitionHandler<TState, TData>(TState initialState, TState nextState);
     }
+    [System.ObsoleteAttribute("Use Akka.Actor.Status.Failure")]
     public class Failure
     {
         public Failure() { }
         public System.Exception Exception { get; set; }
         public System.DateTime Timestamp { get; set; }
     }
+    [System.ObsoleteAttribute("Use List of Akka.Actor.Status.Failure")]
     public class Failures
     {
         public Failures() { }
@@ -1720,16 +1722,20 @@ namespace Akka.Actor
     public abstract class Status
     {
         protected Status() { }
-        public class Failure : Akka.Actor.Status
+        public sealed class Failure : Akka.Actor.Status
         {
             public readonly System.Exception Cause;
+            public readonly object State;
             public Failure(System.Exception cause) { }
+            public Failure(System.Exception cause, object state) { }
             public override string ToString() { }
         }
-        public class Success : Akka.Actor.Status
+        public sealed class Success : Akka.Actor.Status
         {
+            public static readonly Akka.Actor.Status.Success Instance;
             public readonly object Status;
             public Success(object status) { }
+            public override string ToString() { }
         }
     }
     public class StoppingSupervisorStrategy : Akka.Actor.SupervisorStrategyConfigurator

src/core/Akka/Actor/ActorBase.cs

@@ -20,8 +20,10 @@ public abstract class Status
         /// <summary>
         /// Indicates the success of some operation which has been performed
         /// </summary>
-        public class Success : Status
+        public sealed class Success : Status
         {
+            public static readonly Success Instance = new Success(null);
+
             /// <summary>
             /// TBD
             /// </summary>
@@ -35,33 +37,51 @@ public Success(object status)
             {
                 Status = status;
             }
+
+            public override string ToString() => Status is null ? "Success" : $"Success: {Status}";
         }
 
         /// <summary>
         /// Indicates the failure of some operation that was requested and includes an
         /// <see cref="Exception"/> describing the underlying cause of the problem.
         /// </summary>
-        public class Failure : Status
+        public sealed class Failure : Status
         {
             /// <summary>
             /// The cause of the failure
             /// </summary>
             public readonly Exception Cause;
 
+            /// <summary>
+            /// The source state of the failure
+            /// It can be used to send the command message back
+            /// </summary>
+            public readonly object State;
+
             /// <summary>
             /// Initializes a new instance of the <see cref="Failure"/> class.
             /// </summary>
             /// <param name="cause">The cause of the failure</param>
             public Failure(Exception cause)
             {
                 Cause = cause;
+                State = null;
             }
 
-            /// <inheritdoc/>
-            public override string ToString()
+            /// <summary>
+            /// Initializes a new instance of the <see cref="Failure"/> class.
+            /// </summary>
+            /// <param name="cause">The cause of the failure</param>
+            /// <param name="state">The source state of the failure</param>
+            public Failure(Exception cause, object state)
             {
-                return $"Failure: {Cause}";
+                Cause = cause;
+                State = state;
             }
+
+            /// <inheritdoc/>
+            public override string ToString()
+                => State is null ? $"Failure: {Cause}" : $"Failure[{State}]: {Cause}";
         }
     }
 

src/core/Akka/Actor/SupervisorStrategy.cs

@@ -750,6 +750,7 @@ public override int GetHashCode()
     /// <summary>
     /// Collection of failures, used to keep track of how many times a given actor has failed.
     /// </summary>
+    [Obsolete("Use List of Akka.Actor.Status.Failure")]
     public class Failures
     {
         /// <summary>
@@ -769,6 +770,7 @@ public Failures()
     /// <summary>
     ///     Represents a single failure.
     /// </summary>
+    [Obsolete("Use Akka.Actor.Status.Failure")]
     public class Failure
     {
         /// <summary>