Abstract JSON serialization behind installable serializer packages

Core EventFlow no longer depends on Newtonsoft.Json. JSON serialization is
now provided by separate, client-selectable packages:

- EventFlow.Serialization.NewtonsoftJson  (AddNewtonsoftJson)
- EventFlow.Serialization.SystemTextJson  (AddSystemTextJson)

Core changes (breaking):
- Removed JsonSerializer, SingleValueObjectConverter, IJsonOptions/JsonOptions/
  ChainedJsonOptions, JsonOptionsExtensions and ConfigureJson from core.
- Dropped the Newtonsoft.Json package reference.
- Added ThrowingJsonSerializer as the default IJsonSerializer so a missing
  serializer registration fails fast with an actionable message.
- Removed Newtonsoft serialization attributes from core/sub-package types
  ([JsonIgnore] on Metadata/SnapshotMetadata, [JsonConverter] on CacheKey,
  [JsonProperty] on MongoDB data models, [JsonConverter] on example ids).
  These were inert under the dictionary/BSON contracts.
- InMemoryEventPersistence now uses the injected IJsonSerializer.

Behavior preserved: SingleValueObjects keep serializing as objects by default
(the bare-value SingleValueObjectConverter remains an opt-in), so existing
event/snapshot stores remain readable.

Added a provider-agnostic TestSuiteForJsonSerializer conformance suite; both
serializer packages pass it. Test bootstrapping and EventFlow.Tests updated to
register Newtonsoft explicitly.

Note: EventFlow.AspNetCore is not part of the solution and is left untouched.

Author: mml-antire

EventFlow.sln

@@ -35,13 +35,15 @@ public static class EntityFrameworkTestExtensions
         public static IEventFlowOptions ConfigureForEventStoreTest(this IEventFlowOptions options)
         {
             return options
-                .UseEntityFrameworkEventStore<TestDbContext>();
+                .UseEntityFrameworkEventStore<TestDbContext>()
+                .AddNewtonsoftJson();
         }
 
         public static IEventFlowOptions ConfigureForSnapshotStoreTest(this IEventFlowOptions options)
         {
             return options
-                .UseEntityFrameworkSnapshotStore<TestDbContext>();
+                .UseEntityFrameworkSnapshotStore<TestDbContext>()
+                .AddNewtonsoftJson();
         }
 
         public static IEventFlowOptions ConfigureForReadStoreTest(this IEventFlowOptions options)
@@ -53,14 +55,16 @@ public static IEventFlowOptions ConfigureForReadStoreTest(this IEventFlowOptions
                 .AddQueryHandlers(
                     typeof(EfThingyGetQueryHandler),
                     typeof(EfThingyGetVersionQueryHandler),
-                    typeof(EfThingyGetMessagesQueryHandler));
+                    typeof(EfThingyGetMessagesQueryHandler))
+                .AddNewtonsoftJson();
         }
 
         public static IEventFlowOptions ConfigureForReadStoreIncludeTest(this IEventFlowOptions options)
         {
             return options
                 .UseEntityFrameworkReadModel<PersonReadModelEntity, TestDbContext>(cfg => cfg.Include(x => x.Addresses))
-                .AddQueryHandlers(typeof(PersonGetQueryHandler));
+                .AddQueryHandlers(typeof(PersonGetQueryHandler))
+                .AddNewtonsoftJson();
         }
     }
 }

Source/EventFlow.EntityFramework.Tests/EntityFrameworkTestExtensions.cs

@@ -5,5 +5,6 @@
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\EventFlow.Examples.Shipping\EventFlow.Examples.Shipping.csproj" />
+    <ProjectReference Include="..\EventFlow.Serialization.NewtonsoftJson\EventFlow.Serialization.NewtonsoftJson.csproj" />
   </ItemGroup>
 </Project>

Source/EventFlow.Examples.Shipping.Queries.InMemory/EventFlow.Examples.Shipping.Queries.InMemory.csproj

@@ -37,7 +37,8 @@ public static IEventFlowOptions ConfigureShippingQueriesInMemory(
             return eventFlowOptions
                 .AddQueryHandlers(Assembly)
                 .UseInMemoryReadStoreFor<VoyageReadModel>()
-                .UseInMemoryReadStoreFor<CargoReadModel>();
+                .UseInMemoryReadStoreFor<CargoReadModel>()
+                .AddNewtonsoftJson();
         }
     }
 }

Source/EventFlow.Examples.Shipping.Queries.InMemory/EventFlowExamplesShippingQueriesInMemory.cs

@@ -22,11 +22,9 @@
 
 using EventFlow.Core;
 using EventFlow.ValueObjects;
-using Newtonsoft.Json;
 
 namespace EventFlow.Examples.Shipping.Domain.Model.CargoModel
 {
-    [JsonConverter(typeof(SingleValueObjectConverter))]
     public class CargoId : Identity<CargoId>
     {
         public CargoId(string value) : base(value)

Source/EventFlow.Examples.Shipping/Domain/Model/CargoModel/CargoId.cs

@@ -22,11 +22,9 @@
 
 using EventFlow.Core;
 using EventFlow.ValueObjects;
-using Newtonsoft.Json;
 
 namespace EventFlow.Examples.Shipping.Domain.Model.CargoModel.Entities
 {
-    [JsonConverter(typeof(SingleValueObjectConverter))]
     public class TransportLegId : Identity<TransportLegId>
     {
         public TransportLegId(string value) : base(value)

Source/EventFlow.Examples.Shipping/Domain/Model/CargoModel/Entities/TransportLegId.cs

@@ -24,11 +24,9 @@
 using System.Text.RegularExpressions;
 using EventFlow.Core;
 using EventFlow.ValueObjects;
-using Newtonsoft.Json;
 
 namespace EventFlow.Examples.Shipping.Domain.Model.LocationModel
 {
-    [JsonConverter(typeof(SingleValueObjectConverter))]
     public class LocationId : SingleValueObject<string>, IIdentity
     {
         private static readonly Regex ValidValues = new Regex("[a-zA-Z]{2}[a-zA-Z2-9]{3}", RegexOptions.Compiled);

Source/EventFlow.Examples.Shipping/Domain/Model/LocationModel/LocationId.cs

@@ -22,11 +22,9 @@
 
 using EventFlow.Core;
 using EventFlow.ValueObjects;
-using Newtonsoft.Json;
 
 namespace EventFlow.Examples.Shipping.Domain.Model.VoyageModel
 {
-    [JsonConverter(typeof(SingleValueObjectConverter))]
     public class VoyageId : SingleValueObject<string>, IIdentity
     {
         public VoyageId(string value) : base(value)

Source/EventFlow.Examples.Shipping/Domain/Model/VoyageModel/VoyageId.cs

@@ -25,7 +25,6 @@
 using EventFlow.ValueObjects;
 using MongoDB.Bson;
 using MongoDB.Bson.Serialization.Attributes;
-using Newtonsoft.Json;
 
 namespace EventFlow.MongoDB.ValueObjects
 {
@@ -34,25 +33,19 @@ public class MongoDbEventDataModel : ValueObject, ICommittedDomainEvent
         [BsonElement("_id")]
         public long _id { get; set; }
 
-        [JsonProperty("batchId")]
         [BsonGuidRepresentation(GuidRepresentation.Standard)]
         public Guid BatchId { get; set; }
 
         long? _version { get; set; }
 
-        [JsonProperty("aggregateId")]
         public string AggregateId { get; set; }
 
-        [JsonProperty("aggregateName")]
         public string AggregateName { get; set; }
 
-        [JsonProperty("aggregateSequenceNumber")]
         public int AggregateSequenceNumber { get; set; }
 
-        [JsonProperty("data")]
         public string Data { get; set; }
 
-        [JsonProperty("metaData")]
         public string Metadata { get; set; }
     }
 }

Source/EventFlow.MongoDB/ValueObjects/MongoDbEventDataModel.cs

@@ -23,7 +23,6 @@
 using EventFlow.ValueObjects;
 using MongoDB.Bson;
 using MongoDB.Bson.Serialization.Attributes;
-using Newtonsoft.Json;
 
 namespace EventFlow.MongoDB.ValueObjects
 {
@@ -32,15 +31,10 @@ public class MongoDbSnapshotDataModel : ValueObject
         [BsonElement("_id")]
         public ObjectId _id { get; set; }
         long? _version { get; set; }
-        [JsonProperty("aggregateId")]
         public string AggregateId { get; set; }
-        [JsonProperty("aggregateName")]
         public string AggregateName { get; set; }
-        [JsonProperty("aggregateSequenceNumber")]
         public int AggregateSequenceNumber { get; set; }
-        [JsonProperty("data")]
         public string Data { get; set; }
-        [JsonProperty("metaData")]
         public string Metadata { get; set; }
     }
 }