From ffed3eb088bc00f90a5e4b7367d4598fda007401 Mon Sep 17 00:00:00 2001
From: rdavisau <ryandavis.au@gmail.com>
Date: Tue, 1 Sep 2015 01:07:15 +1000
Subject: [PATCH] Throw `TypeLoadException` when an actor type or dependency
 cannot be found in a remote actor deploy scenario Actively handle cases where
 a null actor type is passed to a Props constructor

---
 .../DaemonMsgCreateSerializer.cs              | 18 ++++++++++++++++-
 src/core/Akka.Tests/Actor/PropsSpec.cs        | 20 +++++++++++++++++++
 src/core/Akka/Actor/Props.cs                  | 17 ++++++++++++++++
 3 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/src/core/Akka.Remote/Serialization/DaemonMsgCreateSerializer.cs b/src/core/Akka.Remote/Serialization/DaemonMsgCreateSerializer.cs
index 1d4f2d91252..569df12034c 100644
--- a/src/core/Akka.Remote/Serialization/DaemonMsgCreateSerializer.cs
+++ b/src/core/Akka.Remote/Serialization/DaemonMsgCreateSerializer.cs
@@ -113,7 +113,23 @@ private DeployData GetDeployData(Deploy deploy)
         public override object FromBinary(byte[] bytes, Type type)
         {
             var proto = DaemonMsgCreateData.ParseFrom(bytes);
-            var clazz = Type.GetType(proto.Props.Clazz);
+            Type clazz; 
+
+            try
+            {
+                clazz = Type.GetType(proto.Props.Clazz, true);
+            }
+            catch (TypeLoadException ex)
+            {
+                var msg = string.Format(
+                       "Could not find type '{0}' on the remote system. " +
+                       "Ensure that the remote system has an assembly that contains the type {0} in its assembly search path", 
+                       proto.Props.Clazz);
+
+
+                throw new TypeLoadException(msg, ex);
+            }
+
             var args = GetArgs(proto);
             var props = new Props(GetDeploy(proto.Props.Deploy), clazz, args);
             return new DaemonMsgCreate(
diff --git a/src/core/Akka.Tests/Actor/PropsSpec.cs b/src/core/Akka.Tests/Actor/PropsSpec.cs
index fc40ea51b31..e2df96090dc 100644
--- a/src/core/Akka.Tests/Actor/PropsSpec.cs
+++ b/src/core/Akka.Tests/Actor/PropsSpec.cs
@@ -8,6 +8,7 @@
 using Akka.Actor;
 using Akka.TestKit;
 using System;
+using System.Linq;
 using Xunit;
 
 namespace Akka.Tests.Actor
@@ -56,6 +57,25 @@ public void Props_created_with_strategy_must_have_it_set()
             Assert.Equal(strategy, props.SupervisorStrategy);
         }
 
+        [Fact]
+        public void Props_created_with_null_type_must_throw()
+        {
+            Type missingType = null;
+            object[] args = new object[0];
+            var argsEnumerable = Enumerable.Empty<object>();
+            var defaultStrategy = SupervisorStrategy.DefaultStrategy;
+            var defaultDeploy = Deploy.Local;
+
+            Props p = null;
+
+            Assert.Throws<ArgumentNullException>("type", () => p = new Props(missingType, args));
+            Assert.Throws<ArgumentNullException>("type", () => p = new Props(missingType));
+            Assert.Throws<ArgumentNullException>("type", () => p = new Props(missingType, defaultStrategy, argsEnumerable));
+            Assert.Throws<ArgumentNullException>("type", () => p = new Props(missingType, defaultStrategy, args));
+            Assert.Throws<ArgumentNullException>("type", () => p = new Props(defaultDeploy, missingType, argsEnumerable));
+            Assert.Throws<ArgumentNullException>("type", () => p = Props.Create(missingType, args));
+        }
+        
         private class TestProducer : IIndirectActorProducer
         {
             TestLatch latchActor;
diff --git a/src/core/Akka/Actor/Props.cs b/src/core/Akka/Actor/Props.cs
index 1e33b9d27c3..10b2269e5a4 100644
--- a/src/core/Akka/Actor/Props.cs
+++ b/src/core/Akka/Actor/Props.cs
@@ -32,6 +32,8 @@ namespace Akka.Actor
     /// </summary>
     public class Props : IEquatable<Props> , ISurrogated
     {
+        private const string NullActorTypeExceptionText = "Props must be instantiated with an actor type.";
+
         public class PropsSurrogate : ISurrogate
         {
             public Type Type { get; set; }
@@ -183,6 +185,8 @@ protected Props(Props copy)
         public Props(Type type, object[] args)
             : this(defaultDeploy, type, args)
         {
+            if (type == null)
+                throw new ArgumentNullException("type", NullActorTypeExceptionText);
         }
 
         /// <summary>
@@ -192,6 +196,8 @@ public Props(Type type, object[] args)
         public Props(Type type)
             : this(defaultDeploy, type, noArgs)
         {
+            if (type == null)
+                throw new ArgumentNullException("type", NullActorTypeExceptionText);
         }
 
         /// <summary>
@@ -203,6 +209,9 @@ public Props(Type type)
         public Props(Type type, SupervisorStrategy supervisorStrategy, IEnumerable<object> args)
             : this(defaultDeploy, type, args.ToArray())
         {
+            if (type == null)
+                throw new ArgumentNullException("type", NullActorTypeExceptionText);
+
             SupervisorStrategy = supervisorStrategy;
         }
 
@@ -215,6 +224,9 @@ public Props(Type type, SupervisorStrategy supervisorStrategy, IEnumerable<objec
         public Props(Type type, SupervisorStrategy supervisorStrategy, params object[] args)
             : this(defaultDeploy, type, args)
         {
+            if (type == null)
+                throw new ArgumentNullException("type", NullActorTypeExceptionText);
+
             SupervisorStrategy = supervisorStrategy;
         }
 
@@ -227,6 +239,8 @@ public Props(Type type, SupervisorStrategy supervisorStrategy, params object[] a
         public Props(Deploy deploy, Type type, IEnumerable<object> args)
             : this(deploy, type, args.ToArray())
         {
+            if (type == null)
+                throw new ArgumentNullException("type", NullActorTypeExceptionText);
         }
 
         /// <summary>
@@ -394,6 +408,9 @@ public static Props CreateBy<TProducer>(params object[] args) where TProducer :
         /// <returns>Props.</returns>
         public static Props Create(Type type, params object[] args)
         {
+            if (type == null)
+                throw new ArgumentNullException("type", NullActorTypeExceptionText);
+
             return new Props(type, args);
         }