Add Unit Tests.

Tests/MQTTnet.Core.Tests/TopicFilterComparer_Tests.cs

@@ -6,6 +6,20 @@ namespace MQTTnet.Tests
     [TestClass]
     public class TopicFilterComparer_Tests
     {
+        [TestMethod]
+        public void TopicFilterComparer_Plus_Match_With_Separator_Only()
+        {
+            //A Topic Name or Topic Filter consisting only of the ‘/’ character is valid
+            CompareAndAssert("A", "+", true);
+        }
+
+        [TestMethod]
+        public void TopicFilterComparer_Hash_Match_With_Separator_Only()
+        {
+            //A Topic Name or Topic Filter consisting only of the ‘/’ character is valid
+            CompareAndAssert("/", "#", true);
+        }
+
         [TestMethod]
         public void TopicFilterComparer_DirectMatch()
         {