Stop setting a default serializer (#6923)

* Stop setting a default serializer

* Update existing tests to configure serializer

* Add new test

Author: bording

src/NServiceBus.AcceptanceTests/Core/SubscriptionMigration/AcceptanceTestingTransportServer.cs

@@ -32,6 +32,8 @@ public async Task<EndpointConfiguration> GetConfiguration(RunDescriptor runDescr
         await persistenceConfiguration.Configure(endpointConfiguration.EndpointName, configuration, runDescriptor.Settings, endpointConfiguration.PublisherMetadata);
         runDescriptor.OnTestCompleted(_ => persistenceConfiguration.Cleanup());
 
+        configuration.UseSerialization<SystemJsonSerializer>();
+
         await configurationBuilderCustomization(configuration);
 
         // scan types at the end so that all types used by the configuration have been loaded into the AppDomain

src/NServiceBus.AcceptanceTests/EndpointTemplates/ServerWithNoDefaultPersistenceDefinitions.cs

@@ -21,6 +21,8 @@ public virtual async Task<EndpointConfiguration> GetConfiguration(RunDescriptor
 
         await builder.DefineTransport(TransportConfiguration, runDescriptor, endpointConfiguration).ConfigureAwait(false);
 
+        builder.UseSerialization<SystemJsonSerializer>();
+
         await configurationBuilderCustomization(builder).ConfigureAwait(false);
 
         // scan types at the end so that all types used by the configuration have been loaded into the AppDomain

src/NServiceBus.AcceptanceTests/Serialization/When_defining_serializer_with_no_content_type.cs

@@ -13,7 +13,7 @@
 public class When_defining_serializer_with_no_content_type : NServiceBusAcceptanceTest
 {
     [Test]
-    public void Should_fail_endpoint_startup_for_default_serializer()
+    public void Should_fail_endpoint_startup_for_main_serializer()
     {
         var exception = Assert.ThrowsAsync<ArgumentException>(() => Scenario.Define<ScenarioContext>()
             .WithEndpoint<EndpointWithInvalidSerializer>(e => e

src/NServiceBus.Core.Tests/Config/When_configuring_transport_twice.cs

@@ -15,6 +15,7 @@ public async Task Last_one_wins()
     {
         var config = new EndpointConfiguration("Endpoint");
         config.AssemblyScanner().ExcludeAssemblies("NServiceBus.Core.Tests.dll");
+        config.UseSerialization<SystemJsonSerializer>();
         var transport1 = new FakeTransportDefinition();
         var transport2 = new FakeTransportDefinition();
         config.UseTransport(transport1).DisablePublishing();

src/NServiceBus.Core.Tests/Config/When_starting_an_endpoint_with_already_used_configuration.cs

@@ -11,6 +11,7 @@ public async Task Should_throw()
     {
         var configuration = new EndpointConfiguration("Endpoint1");
         configuration.UseTransport(new LearningTransport());
+        configuration.UseSerialization<SystemJsonSerializer>();
         var scanner = configuration.AssemblyScanner();
         scanner.ExcludeAssemblies("NServiceBus.Core.Tests.dll");
 

src/NServiceBus.Core.Tests/Config/When_starting_endpoint_without_configuring_serializer.cs

@@ -0,0 +1,21 @@
+namespace NServiceBus.Core.Tests.Config;
+
+using System;
+using NUnit.Framework;
+
+[TestFixture]
+class When_starting_endpoint_without_configuring_serializer
+{
+    [Test]
+    public void Should_throw()
+    {
+        var configuration = new EndpointConfiguration("Endpoint1");
+        configuration.UseTransport(new LearningTransport());
+
+        var scanner = configuration.AssemblyScanner();
+        scanner.ExcludeAssemblies("NServiceBus.Core.Tests.dll");
+
+        var exception = Assert.ThrowsAsync<Exception>(async () => await Endpoint.Create(configuration).ConfigureAwait(false));
+        Assert.True(exception.Message.StartsWith("A serializer has not been configured"));
+    }
+}

src/NServiceBus.Core.Tests/Serializers/MessageDeserializerResolverTests.cs

@@ -3,8 +3,8 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using Serialization;
 using NUnit.Framework;
+using Serialization;
 
 [TestFixture]
 public class MessageDeserializerResolverTests
@@ -32,8 +32,8 @@ public void RetrievesSerializerByContentType(string contentType)
     [Test]
     public void UnknownContentTypeFallsBackToDefaultSerialization()
     {
-        var defaultSerializer = new FakeSerializer(ContentTypes.Xml);
-        var resolver = new MessageDeserializerResolver(defaultSerializer, new IMessageSerializer[]
+        var mainSerializer = new FakeSerializer(ContentTypes.Xml);
+        var resolver = new MessageDeserializerResolver(mainSerializer, new IMessageSerializer[]
         {
             new FakeSerializer(ContentTypes.Json)
         });
@@ -44,29 +44,29 @@ public void UnknownContentTypeFallsBackToDefaultSerialization()
         };
         var serializer = resolver.Resolve(headers);
 
-        Assert.AreSame(defaultSerializer, serializer);
+        Assert.AreSame(mainSerializer, serializer);
     }
 
     [Test]
     public void NoContentTypeFallsBackToDefaultSerialization()
     {
-        var defaultSerializer = new FakeSerializer(ContentTypes.Xml);
-        var resolver = new MessageDeserializerResolver(defaultSerializer, new IMessageSerializer[]
+        var mainSerializer = new FakeSerializer(ContentTypes.Xml);
+        var resolver = new MessageDeserializerResolver(mainSerializer, new IMessageSerializer[]
         {
             new FakeSerializer(ContentTypes.Json)
         });
 
         var serializer = resolver.Resolve([]);
 
-        Assert.AreEqual(defaultSerializer, serializer);
+        Assert.AreEqual(mainSerializer, serializer);
     }
 
     [TestCase(null)]
     [TestCase("")]
     public void EmptyContentTypeFallsBackToDefaultSerialization(string headerValue)
     {
-        var defaultSerializer = new FakeSerializer(ContentTypes.Xml);
-        var resolver = new MessageDeserializerResolver(defaultSerializer, new IMessageSerializer[]
+        var mainSerializer = new FakeSerializer(ContentTypes.Xml);
+        var resolver = new MessageDeserializerResolver(mainSerializer, new IMessageSerializer[]
         {
             new FakeSerializer(ContentTypes.Json)
         });
@@ -76,7 +76,7 @@ public void EmptyContentTypeFallsBackToDefaultSerialization(string headerValue)
             { Headers.ContentType, headerValue}
         });
 
-        Assert.AreEqual(defaultSerializer, serializer);
+        Assert.AreEqual(mainSerializer, serializer);
     }
 
     [Test]

src/NServiceBus.Core/Serialization/SerializationFeature.cs

@@ -26,9 +26,9 @@ protected internal sealed override void Setup(FeatureConfigurationContext contex
         var messageMetadataRegistry = settings.Get<MessageMetadataRegistry>();
         mapper.Initialize(messageMetadataRegistry.GetAllMessages().Select(m => m.MessageType));
 
-        var defaultSerializerAndDefinition = settings.GetMainSerializer();
+        var mainSerializerAndDefinition = settings.GetMainSerializer();
 
-        var defaultSerializer = CreateMessageSerializer(defaultSerializerAndDefinition, mapper, settings);
+        var mainSerializer = CreateMessageSerializer(mainSerializerAndDefinition, mapper, settings);
 
         var additionalDeserializerDefinitions = context.Settings.GetAdditionalSerializers();
         var additionalDeserializers = new List<IMessageSerializer>();
@@ -51,10 +51,10 @@ protected internal sealed override void Setup(FeatureConfigurationContext contex
 
         var allowMessageTypeInference = settings.IsMessageTypeInferenceEnabled();
         var allowDynamicTypeLoading = settings.IsDynamicTypeLoadingEnabled();
-        var resolver = new MessageDeserializerResolver(defaultSerializer, additionalDeserializers);
+        var resolver = new MessageDeserializerResolver(mainSerializer, additionalDeserializers);
         var logicalMessageFactory = new LogicalMessageFactory(messageMetadataRegistry, mapper);
         context.Pipeline.Register("DeserializeLogicalMessagesConnector", new DeserializeMessageConnector(resolver, logicalMessageFactory, messageMetadataRegistry, mapper, allowMessageTypeInference), "Deserializes the physical message body into logical messages");
-        context.Pipeline.Register("SerializeMessageConnector", new SerializeMessageConnector(defaultSerializer, messageMetadataRegistry), "Converts a logical message into a physical message");
+        context.Pipeline.Register("SerializeMessageConnector", new SerializeMessageConnector(mainSerializer, messageMetadataRegistry), "Converts a logical message into a physical message");
 
         context.Services.AddSingleton(_ => mapper);
         context.Services.AddSingleton<IMessageCreator>(sp => sp.GetRequiredService<IMessageMapper>());
@@ -65,11 +65,11 @@ protected internal sealed override void Setup(FeatureConfigurationContext contex
 
         context.Settings.AddStartupDiagnosticsSection("Serialization", new
         {
-            DefaultSerializer = new
+            MainSerializer = new
             {
-                Type = defaultSerializerAndDefinition.Item1.GetType().FullName,
-                Version = FileVersionRetriever.GetFileVersion(defaultSerializerAndDefinition.Item1.GetType()),
-                defaultSerializer.ContentType
+                Type = mainSerializerAndDefinition.Item1.GetType().FullName,
+                Version = FileVersionRetriever.GetFileVersion(mainSerializerAndDefinition.Item1.GetType()),
+                mainSerializer.ContentType
             },
             AdditionalDeserializers = additionalDeserializerDiagnostics,
             AllowMessageTypeInference = allowMessageTypeInference,

src/NServiceBus.Core/Serialization/SerializationSettingsExtensions.cs

@@ -38,12 +38,11 @@ public static void SetMainSerializer(this SettingsHolder settings, Serialization
 
     public static Tuple<SerializationDefinition, SettingsHolder> GetMainSerializer(this IReadOnlySettings settings)
     {
-        if (!settings.TryGet(MainSerializerSettingsKey, out Tuple<SerializationDefinition, SettingsHolder> defaultSerializerAndSettings))
+        if (!settings.TryGet(MainSerializerSettingsKey, out Tuple<SerializationDefinition, SettingsHolder> mainSerializerAndSettings))
         {
-            var noDefaultSerializerMsg = $"Because no message serializer was selected, the default {nameof(XmlSerializer)} will be used instead. In a future version of NServiceBus the {nameof(XmlSerializer)} will no longer be the default. For better forward compatibility, either choose a different message serializer, or make the choice of XML serialization explicit using endpointConfiguration.{nameof(SerializationConfigExtensions.UseSerialization)}<{nameof(XmlSerializer)}>()";
-            log.Warn(noDefaultSerializerMsg);
-            defaultSerializerAndSettings = Tuple.Create<SerializationDefinition, SettingsHolder>(new XmlSerializer(), new SettingsHolder());
+            throw new Exception($"A serializer has not been configured. Use 'EndpointConfiguration.{nameof(SerializationConfigExtensions.UseSerialization)}()' to specify a serializer.");
         }
-        return defaultSerializerAndSettings;
+
+        return mainSerializerAndSettings;
     }
 }

src/NServiceBus.Core/Serializers/MessageDeserializerResolver.cs

@@ -6,9 +6,9 @@
 
 class MessageDeserializerResolver
 {
-    public MessageDeserializerResolver(IMessageSerializer defaultSerializer, IEnumerable<IMessageSerializer> additionalDeserializers)
+    public MessageDeserializerResolver(IMessageSerializer mainSerializer, IEnumerable<IMessageSerializer> additionalDeserializers)
     {
-        this.defaultSerializer = defaultSerializer;
+        this.mainSerializer = mainSerializer;
 
         foreach (var additionalDeserializer in additionalDeserializers)
         {
@@ -30,9 +30,10 @@ public IMessageSerializer Resolve(Dictionary<string, string> headers)
                 return serializer;
             }
         }
-        return defaultSerializer;
+
+        return mainSerializer;
     }
 
-    readonly IMessageSerializer defaultSerializer;
+    readonly IMessageSerializer mainSerializer;
     readonly Dictionary<string, IMessageSerializer> serializersMap = [];
 }