Do not allow to pass null topic to IPublishConfiguration (#853)

* Clean up fluent configuration

* Do not allow to set nulls

Author: Pliner

Source/EasyNetQ.Tests/FluentConfiguration/PublishConfigurationTests.cs

@@ -13,12 +13,16 @@ public void Should_throw_if_default_topic_is_null()
         }
 
         [Fact]
-        public void Should_return_default_topic()
+        public void Should_throw_if_customer_topic_is_null()
         {
             var configuration = new PublishConfiguration("default");
+            Assert.Throws<ArgumentNullException>(() => configuration.WithTopic(null));
+        }
 
-            configuration.WithTopic(null);
-
+        [Fact]
+        public void Should_return_default_topic()
+        {
+            var configuration = new PublishConfiguration("default");
             Assert.Equal("default", configuration.Topic);
         }
 
@@ -32,4 +36,4 @@ public void Should_return_custom_topic()
             Assert.Equal("custom", configuration.Topic);
         }
     }
-}
+}

Source/EasyNetQ/FluentConfiguration/IPublishConfiguration.cs

@@ -1,10 +1,8 @@
-using System;
-
-namespace EasyNetQ.FluentConfiguration
+namespace EasyNetQ.FluentConfiguration
 {
     /// <summary>
     /// Allows publish configuration to be fluently extended without adding overloads to IBus
-    /// 
+    ///
     /// e.g.
     /// x => x.WithTopic("*.brighton").WithPriority(2)
     /// </summary>
@@ -41,13 +39,11 @@ public interface IPublishConfiguration
 
     public class PublishConfiguration : IPublishConfiguration
     {
-        private readonly string defaultTopic;
-
         public PublishConfiguration(string defaultTopic)
         {
             Preconditions.CheckNotNull(defaultTopic, "defaultTopic");
 
-            this.defaultTopic = defaultTopic;
+            Topic = defaultTopic;
         }
 
         public IPublishConfiguration WithPriority(byte priority)
@@ -58,6 +54,8 @@ public IPublishConfiguration WithPriority(byte priority)
 
         public IPublishConfiguration WithTopic(string topic)
         {
+            Preconditions.CheckNotNull(topic, "topic");
+
             Topic = topic;
             return this;
         }
@@ -75,16 +73,8 @@ public IPublishConfiguration WithQueueName(string queueName)
         }
 
         public byte? Priority { get; private set; }
-
-        private string topic;
-
-        public string Topic
-        {
-            get { return topic ?? defaultTopic; }
-            private set { topic = value; }
-        }
-
+        public string Topic { get; private set; }
         public int? Expires { get; private set; }
         public string QueueName { get; private set; }
     }
-}
+}

Source/EasyNetQ/FluentConfiguration/IRequestConfiguration.cs

@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace EasyNetQ.FluentConfiguration
+namespace EasyNetQ.FluentConfiguration
 {
     /// <summary>
     /// Allows request configuration to be fluently extended without adding overloads to IBus

Source/EasyNetQ/FluentConfiguration/ISubscriptionConfiguration.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Collections.Generic;
+using System.Collections.Generic;
 
 namespace EasyNetQ.FluentConfiguration
 {