Use Json TypeInfoResolverChain (#47450)

* Use Json TypeInfoResolverChain

- Removes all usages of JsonSerializerOptions.AddContext, which will be obsoleted by dotnet/runtime#83280
- Update ProblemDetailsJsonContext to be added in a Configure<JsonOptions>() call back and to always be added to the beginning of the resolver chain at that time
    - This gives us the simplest, most understandable pattern for all libraries to follow.
- Small clean up in the API template's usings

* Change ProblemDetailsJsonOptionsSetup to use Configure instead of PostConfigure.

When adding the ProblemDetailsJsonContext, we always prepend it to the beginning of the chain at the time the configure step is executed, no matter the state of the chain.

This allows for a simpler, more understandable policy for all libraries that want to add their JsonContext into the JsonSerializerOptions resolver chain. The order of the chain is now determined by the order that the configure steps were registered in DI (for example when AddProblemDetails() was called).

Author: eerhardt

src/Http/Http.Extensions/src/JsonOptions.cs

@@ -6,8 +6,6 @@
 using System.Text.Json.Serialization.Metadata;
 using Microsoft.AspNetCore.Internal;
 
-#nullable enable
-
 namespace Microsoft.AspNetCore.Http.Json;
 
 /// <summary>
@@ -18,23 +16,23 @@ public class JsonOptions
 {
     internal static readonly JsonSerializerOptions DefaultSerializerOptions = new JsonSerializerOptions(JsonSerializerDefaults.Web)
     {
-        // Web defaults don't use the relex JSON escaping encoder.
+        // Web defaults don't use the relaxed JSON escaping encoder.
         //
         // Because these options are for producing content that is written directly to the request
         // (and not embedded in an HTML page for example), we can use UnsafeRelaxedJsonEscaping.
         Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
 
         // The JsonSerializerOptions.GetTypeInfo method is called directly and needs a defined resolver
-        // setting the default resolver (reflection-based) but the user can overwrite it directly or calling
-        // .AddContext<TContext>()
+        // setting the default resolver (reflection-based) but the user can overwrite it directly or by modifying
+        // the TypeInfoResolverChain
         TypeInfoResolver = TrimmingAppContextSwitches.EnsureJsonTrimmability ? null : CreateDefaultTypeResolver()
     };
 
     // Use a copy so the defaults are not modified.
     /// <summary>
     /// Gets the <see cref="JsonSerializerOptions"/>.
     /// </summary>
-    public JsonSerializerOptions SerializerOptions { get; internal set; } = new JsonSerializerOptions(DefaultSerializerOptions);
+    public JsonSerializerOptions SerializerOptions { get; } = new JsonSerializerOptions(DefaultSerializerOptions);
 
 #pragma warning disable IL2026 // Suppressed in Microsoft.AspNetCore.Http.Extensions.WarningSuppressions.xml
 #pragma warning disable IL3050 // Calling members annotated with 'RequiresDynamicCodeAttribute' may break functionality when AOT compiling.

src/Http/Http.Extensions/src/ProblemDetailsJsonOptionsSetup.cs

@@ -1,33 +1,26 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System.Text.Json.Serialization.Metadata;
 using Microsoft.AspNetCore.Http.Json;
 using Microsoft.Extensions.Options;
 
 namespace Microsoft.AspNetCore.Http;
 
-internal sealed class ProblemDetailsJsonOptionsSetup : IPostConfigureOptions<JsonOptions>
+/// <summary>
+/// Adds the ProblemDetailsJsonContext to the current JsonSerializerOptions.
+///
+/// This allows for consistent serialization behavior for ProblemDetails regardless if
+/// the default reflection-based serializer is used or not. And makes it trim/NativeAOT compatible.
+/// </summary>
+internal sealed class ProblemDetailsJsonOptionsSetup : IConfigureOptions<JsonOptions>
 {
-    public void PostConfigure(string? name, JsonOptions options)
+    public void Configure(JsonOptions options)
     {
-        switch (options.SerializerOptions.TypeInfoResolver)
-        {
-            case DefaultJsonTypeInfoResolver:
-                // In this case, the current configuration is using a reflection-based resolver
-                // and we are prepending our internal problem details context to be evaluated
-                // first.
-                options.SerializerOptions.TypeInfoResolver = JsonTypeInfoResolver.Combine(ProblemDetailsJsonContext.Default, options.SerializerOptions.TypeInfoResolver);
-                break;
-            case not null:
-                // Combine the current resolver with our internal problem details context (adding last)
-                options.SerializerOptions.AddContext<ProblemDetailsJsonContext>();
-                break;
-            default:
-                // Not adding our source gen context when TypeInfoResolver == null
-                // since adding it will skip the reflection-based resolver and potentially
-                // cause unexpected serialization problems
-                break;
-        }
+        // Always insert the ProblemDetailsJsonContext to the beginning of the chain at the time
+        // this Configure is invoked. This JsonTypeInfoResolver will be before the default reflection-based resolver,
+        // and before any other resolvers currently added.
+        // If apps need to customize ProblemDetails serialization, they can prepend a custom ProblemDetails resolver
+        // to the chain in an IConfigureOptions<JsonOptions> registered after the call to AddProblemDetails().
+        options.SerializerOptions.TypeInfoResolverChain.Insert(0, new ProblemDetailsJsonContext());
     }
 }

src/Http/Http.Extensions/src/ProblemDetailsServiceCollectionExtensions.cs

@@ -40,7 +40,8 @@ public static IServiceCollection AddProblemDetails(
         // Adding default services;
         services.TryAddSingleton<IProblemDetailsService, ProblemDetailsService>();
         services.TryAddEnumerable(ServiceDescriptor.Singleton<IProblemDetailsWriter, DefaultProblemDetailsWriter>());
-        services.TryAddEnumerable(ServiceDescriptor.Singleton<IPostConfigureOptions<JsonOptions>, ProblemDetailsJsonOptionsSetup>());
+        // Use IConfigureOptions (instead of post-configure) so the registration gets added/invoked relative to when AddProblemDetails() is called.
+        services.TryAddEnumerable(ServiceDescriptor.Singleton<IConfigureOptions<JsonOptions>, ProblemDetailsJsonOptionsSetup>());
 
         if (configure != null)
         {

src/Http/Http.Extensions/test/ProblemDetailsServiceCollectionExtensionsTest.cs

@@ -1,9 +1,9 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Text.Json;
 using System.Text.Json.Serialization;
 using System.Text.Json.Serialization.Metadata;
-using Microsoft.AspNetCore.Http.Json;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
@@ -27,7 +27,7 @@ public void AddProblemDetails_AddsNeededServices()
         // Assert
         Assert.Single(collection, (sd) => sd.ServiceType == typeof(IProblemDetailsService) && sd.ImplementationType == typeof(ProblemDetailsService));
         Assert.Single(collection, (sd) => sd.ServiceType == typeof(IProblemDetailsWriter) && sd.ImplementationType == typeof(DefaultProblemDetailsWriter));
-        Assert.Single(collection, (sd) => sd.ServiceType == typeof(IPostConfigureOptions<JsonOptions>) && sd.ImplementationType == typeof(ProblemDetailsJsonOptionsSetup));
+        Assert.Single(collection, (sd) => sd.ServiceType == typeof(IConfigureOptions<JsonOptions>) && sd.ImplementationType == typeof(ProblemDetailsJsonOptionsSetup));
     }
 
     [Fact]
@@ -43,7 +43,7 @@ public void AddProblemDetails_DoesNotDuplicate_WhenMultipleCalls()
         // Assert
         Assert.Single(collection, (sd) => sd.ServiceType == typeof(IProblemDetailsService) && sd.ImplementationType == typeof(ProblemDetailsService));
         Assert.Single(collection, (sd) => sd.ServiceType == typeof(IProblemDetailsWriter) && sd.ImplementationType == typeof(DefaultProblemDetailsWriter));
-        Assert.Single(collection, (sd) => sd.ServiceType == typeof(IPostConfigureOptions<JsonOptions>) && sd.ImplementationType == typeof(ProblemDetailsJsonOptionsSetup));
+        Assert.Single(collection, (sd) => sd.ServiceType == typeof(IConfigureOptions<JsonOptions>) && sd.ImplementationType == typeof(ProblemDetailsJsonOptionsSetup));
     }
 
     [Fact]
@@ -109,7 +109,8 @@ public void AddProblemDetails_Throws_ForReadOnlyJsonOptions()
         // Arrange
         var collection = new ServiceCollection();
         collection.AddOptions<JsonOptions>();
-        collection.ConfigureAll<JsonOptions>(options => {
+        collection.ConfigureAll<JsonOptions>(options =>
+        {
             options.SerializerOptions.TypeInfoResolver = new TestExtensionsJsonContext();
             options.SerializerOptions.MakeReadOnly();
         });
@@ -124,13 +125,35 @@ public void AddProblemDetails_Throws_ForReadOnlyJsonOptions()
         Assert.Throws<InvalidOperationException>(() => jsonOptions.Value);
     }
 
-    [Fact]
-    public void AddProblemDetails_CombinesProblemDetailsContext_WhenAddContext()
+    public enum CustomContextBehavior
+    {
+        Prepend,
+        Append,
+        Replace,
+    }
+
+    [Theory]
+    [InlineData(CustomContextBehavior.Prepend)]
+    [InlineData(CustomContextBehavior.Append)]
+    [InlineData(CustomContextBehavior.Replace)]
+    public void AddProblemDetails_CombinesProblemDetailsContext_WhenAddingCustomContext(CustomContextBehavior behavior)
     {
         // Arrange
         var collection = new ServiceCollection();
         collection.AddOptions<JsonOptions>();
-        collection.ConfigureAll<JsonOptions>(options => options.SerializerOptions.AddContext<TestExtensionsJsonContext>());
+
+        if (behavior == CustomContextBehavior.Prepend)
+        {
+            collection.ConfigureAll<JsonOptions>(options => options.SerializerOptions.TypeInfoResolverChain.Insert(0, TestExtensionsJsonContext.Default));
+        }
+        else if (behavior == CustomContextBehavior.Append)
+        {
+            collection.ConfigureAll<JsonOptions>(options => options.SerializerOptions.TypeInfoResolverChain.Add(TestExtensionsJsonContext.Default));
+        }
+        else
+        {
+            collection.ConfigureAll<JsonOptions>(options => options.SerializerOptions.TypeInfoResolver = TestExtensionsJsonContext.Default);
+        }
 
         // Act
         collection.AddProblemDetails();
@@ -146,7 +169,7 @@ public void AddProblemDetails_CombinesProblemDetailsContext_WhenAddContext()
     }
 
     [Fact]
-    public void AddProblemDetails_DoesNotCombineProblemDetailsContext_WhenNullTypeInfoResolver()
+    public void AddProblemDetails_CombinesProblemDetailsContext_EvenWhenNullTypeInfoResolver()
     {
         // Arrange
         var collection = new ServiceCollection();
@@ -161,7 +184,8 @@ public void AddProblemDetails_DoesNotCombineProblemDetailsContext_WhenNullTypeIn
         var jsonOptions = services.GetService<IOptions<JsonOptions>>();
 
         Assert.NotNull(jsonOptions.Value);
-        Assert.Null(jsonOptions.Value.SerializerOptions.TypeInfoResolver);
+        Assert.NotNull(jsonOptions.Value.SerializerOptions.TypeInfoResolver);
+        Assert.NotNull(jsonOptions.Value.SerializerOptions.TypeInfoResolver.GetTypeInfo(typeof(ProblemDetails), jsonOptions.Value.SerializerOptions));
     }
 
     [Fact]
@@ -186,9 +210,55 @@ public void AddProblemDetails_CombineProblemDetailsContext_WhenDefaultTypeInfoRe
         Assert.NotNull(jsonOptions.Value.SerializerOptions.TypeInfoResolver.GetTypeInfo(typeof(TypeA), jsonOptions.Value.SerializerOptions));
     }
 
+    [Fact]
+    public void AddProblemDetails_CanHaveCustomJsonTypeInfo()
+    {
+        // Arrange
+        var collection = new ServiceCollection();
+        collection.AddOptions<JsonOptions>();
+
+        // Act
+        collection.AddProblemDetails();
+
+        // add any custom ProblemDetails TypeInfoResolvers after calling AddProblemDetails()
+        var customProblemDetailsResolver = new CustomProblemDetailsTypeInfoResolver();
+        collection.ConfigureAll<JsonOptions>(options => options.SerializerOptions.TypeInfoResolverChain.Insert(0, customProblemDetailsResolver));
+
+        // Assert
+        var services = collection.BuildServiceProvider();
+        var jsonOptions = services.GetService<IOptions<JsonOptions>>();
+
+        Assert.NotNull(jsonOptions.Value);
+        Assert.NotNull(jsonOptions.Value.SerializerOptions.TypeInfoResolver);
+
+        Assert.Equal(3, jsonOptions.Value.SerializerOptions.TypeInfoResolverChain.Count);
+        Assert.IsType<CustomProblemDetailsTypeInfoResolver>(jsonOptions.Value.SerializerOptions.TypeInfoResolverChain[0]);
+        Assert.Equal("Microsoft.AspNetCore.Http.ProblemDetailsJsonContext", jsonOptions.Value.SerializerOptions.TypeInfoResolverChain[1].GetType().FullName);
+        Assert.IsType<DefaultJsonTypeInfoResolver>(jsonOptions.Value.SerializerOptions.TypeInfoResolverChain[2]);
+
+        var pdTypeInfo = jsonOptions.Value.SerializerOptions.GetTypeInfo(typeof(ProblemDetails));
+        Assert.Same(customProblemDetailsResolver.LastProblemDetailsInfo, pdTypeInfo);
+    }
+
     [JsonSerializable(typeof(TypeA))]
     internal partial class TestExtensionsJsonContext : JsonSerializerContext
     { }
 
     public class TypeA { }
+
+    internal class CustomProblemDetailsTypeInfoResolver : IJsonTypeInfoResolver
+    {
+        public JsonTypeInfo LastProblemDetailsInfo { get; set; }
+
+        public JsonTypeInfo GetTypeInfo(Type type, JsonSerializerOptions options)
+        {
+            if (type == typeof(ProblemDetails))
+            {
+                LastProblemDetailsInfo = JsonTypeInfo.CreateJsonTypeInfo<ProblemDetails>(options);
+                return LastProblemDetailsInfo;
+            }
+
+            return null;
+        }
+    }
 }

src/Http/Http.Results/test/HttpResultsHelperTests.cs

@@ -30,7 +30,7 @@ public async Task WriteResultAsJsonAsync_Works_ForValueTypes(bool useJsonContext
 
         if (useJsonContext)
         {
-            serializerOptions.AddContext<TestJsonContext>();
+            serializerOptions.TypeInfoResolver = TestJsonContext.Default;
         }
 
         // Act
@@ -61,7 +61,7 @@ public async Task WriteResultAsJsonAsync_Works_ForReferenceTypes(bool useJsonCon
 
         if (useJsonContext)
         {
-            serializerOptions.AddContext<TestJsonContext>();
+            serializerOptions.TypeInfoResolver = TestJsonContext.Default;
         }
 
         // Act
@@ -94,7 +94,7 @@ public async Task WriteResultAsJsonAsync_Works_ForChildTypes(bool useJsonContext
 
         if (useJsonContext)
         {
-            serializerOptions.AddContext<TestJsonContext>();
+            serializerOptions.TypeInfoResolver = TestJsonContext.Default;
         }
 
         // Act
@@ -128,7 +128,7 @@ public async Task WriteResultAsJsonAsync_Works_UsingBaseType_ForChildTypes(bool
 
         if (useJsonContext)
         {
-            serializerOptions.AddContext<TestJsonContext>();
+            serializerOptions.TypeInfoResolver = TestJsonContext.Default;
         }
 
         // Act
@@ -162,7 +162,7 @@ public async Task WriteResultAsJsonAsync_Works_UsingBaseType_ForChildTypes_WithJ
 
         if (useJsonContext)
         {
-            serializerOptions.AddContext<TestJsonContext>();
+            serializerOptions.TypeInfoResolver = TestJsonContext.Default;
         }
 
         // Act

src/Mvc/Mvc.Core/src/JsonOptions.cs

@@ -41,8 +41,8 @@ public class JsonOptions
         MaxDepth = MvcOptions.DefaultMaxModelBindingRecursionDepth,
 
         // The JsonSerializerOptions.GetTypeInfo method is called directly and needs a defined resolver
-        // setting the default resolver (reflection-based) but the user can overwrite it directly or calling
-        // .AddContext<TContext>()
+        // setting the default resolver (reflection-based) but the user can overwrite it directly or by modifying
+        // the TypeInfoResolverChain
         TypeInfoResolver = TrimmingAppContextSwitches.EnsureJsonTrimmability ? null : CreateDefaultTypeResolver()
     };
 

src/ProjectTemplates/Web.ProjectTemplates/content/Api-CSharp/Program.Main.cs

@@ -1,7 +1,6 @@
-using System.Text.Json.Serialization;
 #if NativeAot
-using Microsoft.AspNetCore.Http.Json;
-using Microsoft.Extensions.Options;
+using System.Text.Json.Serialization;
+
 #endif
 namespace Company.ApiApplication1;
 
@@ -15,7 +14,7 @@ public static void Main(string[] args)
         #if (NativeAot)
         builder.Services.ConfigureHttpJsonOptions(options =>
         {
-            options.SerializerOptions.AddContext<AppJsonSerializerContext>();
+            options.SerializerOptions.TypeInfoResolverChain.Insert(0, AppJsonSerializerContext.Default);
         });
 
         #endif

src/ProjectTemplates/Web.ProjectTemplates/content/Api-CSharp/Program.cs

@@ -9,7 +9,7 @@
 #if (NativeAot)
 builder.Services.ConfigureHttpJsonOptions(options =>
 {
-    options.SerializerOptions.AddContext<AppJsonSerializerContext>();
+    options.SerializerOptions.TypeInfoResolverChain.Insert(0, AppJsonSerializerContext.Default);
 });
 
 #endif