Add registering actor from Type in runtime

src/Dapr.Actors/Runtime/ActorRegistrationCollection.cs

@@ -78,7 +78,26 @@ public void RegisterActor<TActor>(string actorTypeName, Action<ActorRegistration
         public void RegisterActor<TActor>(string actorTypeName, ActorRuntimeOptions typeOptions, Action<ActorRegistration> configure = null)
             where TActor : Actor
         {
-            var actorTypeInfo = ActorTypeInformation.Get(typeof(TActor), actorTypeName);
+            RegisterActor(typeof(TActor), actorTypeName, typeOptions, configure);
+        }
+
+        /// <summary>
+        /// Registers an actor type in the collection.
+        /// </summary>
+        /// <param name="actionType">Type of actor.</param>
+        /// <param name="actorTypeName">The name of the actor type represented by the actor.</param>
+        /// <param name="typeOptions">An optional <see cref="ActorRuntimeOptions"/> that defines values for this type alone.</param>
+        /// <param name="configure">An optional delegate used to configure the actor registration.</param>
+        /// <remarks>The value of <paramref name="actorTypeName"/> will have precedence over the default actor type name derived from the actor implementation type or any type name set via <see cref="ActorAttribute"/>.</remarks>
+        /// <exception cref="ArgumentException">The specified actionType is not a subclass of Actor.</exception>
+        public void RegisterActor(Type actionType, string actorTypeName, ActorRuntimeOptions typeOptions, Action<ActorRegistration> configure = null)
+        {
+            if (!actionType.IsSubclassOf(typeof(Actor)))
+            { 
+                throw new ArgumentException("ActionType must be a subclass of Actor.", nameof(actionType));
+            }
+
+            var actorTypeInfo = ActorTypeInformation.Get(actionType, actorTypeName);
             var registration = new ActorRegistration(actorTypeInfo, typeOptions);
             configure?.Invoke(registration);
             this.Add(registration);

test/Dapr.Actors.Test/Runtime/ActorRuntimeTests.cs

@@ -41,6 +41,19 @@ private interface ITestActor : IActor
         {
         }
 
+        [Fact]
+        public void TestRegisterActorFromTypeInRuntime()
+        {
+            var actorType = typeof(TestActor);
+
+            var options = new ActorRuntimeOptions();
+            options.Actors.RegisterActor(actorType, null, null);
+            var runtime = new ActorRuntime(options, loggerFactory, activatorFactory, proxyFactory);
+
+            Assert.Contains(actorType.Name, runtime.RegisteredActors.Select(a => a.Type.ActorTypeName), StringComparer.InvariantCulture);
+            Assert.Throws<ArgumentException>(() => options.Actors.RegisterActor(typeof(FakeActor), null, null));
+        }
+
         [Fact]
         public void TestInferredActorType()
         {
@@ -316,6 +329,10 @@ public async Task TestActorSettingsWithPerActorConfigurations()
             Assert.Equal(32, element.GetInt32());
         }
 
+        private sealed class FakeActor 
+        {
+        }
+
         private sealed class TestActor : Actor, ITestActor
         {
             public TestActor(ActorHost host)