added extension method

Frameworks/MQTTnet.NetStandard/ApplicationMessagePublisherExtensions.cs

@@ -19,7 +19,9 @@ namespace MQTTnet
             if (publisher == null) throw new ArgumentNullException(nameof(publisher));
             if (topic == null) throw new ArgumentNullException(nameof(topic));
             
-            return publisher.PublishAsync(new MqttApplicationMessageBuilder().WithTopic(topic).Build());
+            return publisher.PublishAsync(builder => builder
+                .WithTopic(topic)
+            );
         }
 
         public static Task PublishAsync(this IApplicationMessagePublisher publisher, string topic, string payload)
@@ -27,7 +29,10 @@ namespace MQTTnet
             if (publisher == null) throw new ArgumentNullException(nameof(publisher));
             if (topic == null) throw new ArgumentNullException(nameof(topic));
 
-            return publisher.PublishAsync(new MqttApplicationMessageBuilder().WithTopic(topic).WithPayload(payload).Build());
+            return publisher.PublishAsync(builder => builder
+                .WithTopic(topic)
+                .WithPayload(payload)
+            );
         }
 
         public static Task PublishAsync(this IApplicationMessagePublisher publisher, string topic, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
@@ -35,7 +40,17 @@ namespace MQTTnet
             if (publisher == null) throw new ArgumentNullException(nameof(publisher));
             if (topic == null) throw new ArgumentNullException(nameof(topic));
 
-            return publisher.PublishAsync(new MqttApplicationMessageBuilder().WithTopic(topic).WithPayload(payload).WithQualityOfServiceLevel(qualityOfServiceLevel).Build());
+            return publisher.PublishAsync(builder => builder
+                .WithTopic(topic)
+                .WithPayload(payload)
+                .WithQualityOfServiceLevel(qualityOfServiceLevel)
+            );
+        }
+
+        public static Task PublishAsync(this IApplicationMessagePublisher publisher, Func<MqttApplicationMessageBuilder, MqttApplicationMessageBuilder> builder)
+        {
+            var message = builder(new MqttApplicationMessageBuilder()).Build();
+            return publisher.PublishAsync(message);
         }
     }
 }

Tests/MQTTnet.Core.Tests/MqttServerTests.cs

@@ -214,7 +214,7 @@ namespace MQTTnet.Core.Tests
                 await s.StartAsync(new MqttServerOptions());
 
                 var c1 = await serverAdapter.ConnectTestClient("c1");
-                await c1.PublishAsync(new MqttApplicationMessageBuilder().WithTopic("retained").WithPayload(new byte[3]).Build());
+                await c1.PublishAsync(builder => builder.WithTopic("retained").WithPayload(new byte[3]));
                 await c1.DisconnectAsync();
 
                 var c2 = await serverAdapter.ConnectTestClient("c2");
@@ -272,8 +272,8 @@ namespace MQTTnet.Core.Tests
                 await s.StartAsync(new MqttServerOptions());
 
                 var c1 = await serverAdapter.ConnectTestClient("c1");
-                await c1.PublishAsync(new MqttApplicationMessageBuilder().WithTopic("retained").WithPayload(new byte[3]).WithRetainFlag().Build());
-                await c1.PublishAsync(new MqttApplicationMessageBuilder().WithTopic("retained").WithPayload(new byte[0]).WithRetainFlag().Build());
+                await c1.PublishAsync(builder => builder.WithTopic("retained").WithPayload(new byte[3]).WithRetainFlag());
+                await c1.PublishAsync(builder => builder.WithTopic("retained").WithPayload(new byte[0]).WithRetainFlag());
                 await c1.DisconnectAsync();
 
                 var c2 = await serverAdapter.ConnectTestClient("c2");
@@ -366,8 +366,7 @@ namespace MQTTnet.Core.Tests
                     isIntercepted = string.Compare("extended", Encoding.UTF8.GetString(args.ApplicationMessage.Payload), StringComparison.Ordinal) == 0;
                 };
 
-                var m = new MqttApplicationMessageBuilder().WithTopic("test").Build();
-                await c1.PublishAsync(m);
+                await c1.PublishAsync(builder => builder.WithTopic("test"));
                 await c1.DisconnectAsync();
 
                 await Task.Delay(500);
@@ -403,7 +402,7 @@ namespace MQTTnet.Core.Tests
                 };
 
                 await c1.SubscribeAsync("A", MqttQualityOfServiceLevel.AtMostOnce);
-                await c2.PublishAsync(new MqttApplicationMessageBuilder().WithTopic("A").WithPayload(Encoding.UTF8.GetBytes("The body")).Build());
+                await c2.PublishAsync(builder => builder.WithTopic("A").WithPayload(Encoding.UTF8.GetBytes("The body")));
 
                 await Task.Delay(1000);
             }
@@ -452,7 +451,7 @@ namespace MQTTnet.Core.Tests
                 c1.ApplicationMessageReceived += (_, __) => receivedMessagesCount++;
 
                 await c1.SubscribeAsync(new TopicFilterBuilder().WithTopic(topicFilter).WithQualityOfServiceLevel(filterQualityOfServiceLevel).Build());
-                await c2.PublishAsync(new MqttApplicationMessageBuilder().WithTopic(topic).WithPayload(new byte[0]).WithQualityOfServiceLevel(qualityOfServiceLevel).Build());
+                await c2.PublishAsync(builder => builder.WithTopic(topic).WithPayload(new byte[0]).WithQualityOfServiceLevel(qualityOfServiceLevel));
 
                 await Task.Delay(500);
                 await c1.UnsubscribeAsync(topicFilter);

Tests/MQTTnet.TestApp.NetCore/ManagedClientTest.cs

@@ -39,15 +39,15 @@ namespace MQTTnet.TestApp.NetCore
                     Console.WriteLine(">> RECEIVED: " + e.ApplicationMessage.Topic);
                 };
 
-                await managedClient.PublishAsync(new MqttApplicationMessageBuilder().WithTopic("Step").WithPayload("1").Build());
-                await managedClient.PublishAsync(new MqttApplicationMessageBuilder().WithTopic("Step").WithPayload("2").WithAtLeastOnceQoS().Build());
+                await managedClient.PublishAsync(builder => builder.WithTopic("Step").WithPayload("1"));
+                await managedClient.PublishAsync(builder => builder.WithTopic("Step").WithPayload("2").WithAtLeastOnceQoS());
 
                 await managedClient.StartAsync(options);
 
                 await managedClient.SubscribeAsync(new TopicFilter("xyz", MqttQualityOfServiceLevel.AtMostOnce));
                 await managedClient.SubscribeAsync(new TopicFilter("abc", MqttQualityOfServiceLevel.AtMostOnce));
                 
-                await managedClient.PublishAsync(new MqttApplicationMessageBuilder().WithTopic("Step").WithPayload("3").Build());
+                await managedClient.PublishAsync(builder => builder.WithTopic("Step").WithPayload("3"));
 
                 Console.WriteLine("Managed client started.");
                 Console.ReadLine();