[Blazor] Use JSON source generator during WebAssembly startup (#54956)

Author: MackinnonBuck

src/Components/Shared/src/JsonSerialization/JsonConverterFactoryTypeInfoResolver.cs

@@ -0,0 +1,45 @@
+// 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;
+
+namespace Microsoft.AspNetCore.Components;
+
+// For custom converters that don't rely on serializing an object graph,
+// we can resolve the incoming type's JsonTypeInfo directly from the converter.
+// This skips extra work to collect metadata for the type that won't be used.
+internal sealed class JsonConverterFactoryTypeInfoResolver<T> : IJsonTypeInfoResolver
+{
+    public static readonly JsonConverterFactoryTypeInfoResolver<T> Instance = new();
+
+    private JsonConverterFactoryTypeInfoResolver()
+    {
+    }
+
+    public JsonTypeInfo? GetTypeInfo(Type type, JsonSerializerOptions options)
+    {
+        if (type != typeof(T))
+        {
+            return null;
+        }
+
+        foreach (var converter in options.Converters)
+        {
+            if (converter is not JsonConverterFactory factory || !factory.CanConvert(type))
+            {
+                continue;
+            }
+
+            if (factory.CreateConverter(type, options) is not { } converterToUse)
+            {
+                continue;
+            }
+
+            return JsonMetadataServices.CreateValueInfo<T>(options, converterToUse);
+        }
+
+        return null;
+    }
+}

src/Components/Web/src/Internal/IInternalWebJSInProcessRuntime.cs

@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
+using Microsoft.JSInterop;
+
+namespace Microsoft.AspNetCore.Components.Web.Internal;
+
+/// <summary>
+/// For internal framework use only.
+/// </summary>
+[EditorBrowsable(EditorBrowsableState.Never)]
+public interface IInternalWebJSInProcessRuntime
+{
+    /// <summary>
+    /// For internal framework use only.
+    /// </summary>
+    string InvokeJS(string identifier, [StringSyntax(StringSyntaxAttribute.Json)] string? argsJson, JSCallResultType resultType, long targetInstanceId);
+}

src/Components/Web/src/Microsoft.AspNetCore.Components.Web.csproj

@@ -16,6 +16,7 @@
     <Compile Include="$(ComponentsSharedSourceRoot)src\AttributeUtilities.cs" LinkBase="Forms" />
     <Compile Include="$(ComponentsSharedSourceRoot)src\ExpressionFormatting\**\*.cs" LinkBase="Forms\ExpressionFommatting" />
     <Compile Include="$(ComponentsSharedSourceRoot)src\DefaultAntiforgeryStateProvider.cs" LinkBase="Forms" />
+    <Compile Include="$(ComponentsSharedSourceRoot)src\JsonSerialization\JsonConverterFactoryTypeInfoResolver.cs" LinkBase="JsonSerialization" />
   </ItemGroup>
 
   <ItemGroup>

src/Components/Web/src/PublicAPI.Unshipped.txt

@@ -1,3 +1,5 @@
 #nullable enable
+Microsoft.AspNetCore.Components.Web.Internal.IInternalWebJSInProcessRuntime
+Microsoft.AspNetCore.Components.Web.Internal.IInternalWebJSInProcessRuntime.InvokeJS(string! identifier, string? argsJson, Microsoft.JSInterop.JSCallResultType resultType, long targetInstanceId) -> string!
 Microsoft.AspNetCore.Components.Web.KeyboardEventArgs.IsComposing.get -> bool
 Microsoft.AspNetCore.Components.Web.KeyboardEventArgs.IsComposing.set -> void

src/Components/Web/src/WebRenderer.cs

@@ -3,8 +3,10 @@
 
 using System.Diagnostics.CodeAnalysis;
 using System.Text.Json;
+using System.Text.Json.Serialization;
 using Microsoft.AspNetCore.Components.Web;
 using Microsoft.AspNetCore.Components.Web.Infrastructure;
+using Microsoft.AspNetCore.Components.Web.Internal;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.JSInterop;
@@ -41,12 +43,7 @@ public WebRenderer(
         // Supply a DotNetObjectReference to JS that it can use to call us back for events etc.
         jsComponentInterop.AttachToRenderer(this);
         var jsRuntime = serviceProvider.GetRequiredService<IJSRuntime>();
-        jsRuntime.InvokeVoidAsync(
-            "Blazor._internal.attachWebRendererInterop",
-            _rendererId,
-            _interopMethodsReference,
-            jsComponentInterop.Configuration.JSComponentParametersByIdentifier,
-            jsComponentInterop.Configuration.JSComponentIdentifiersByInitializer).Preserve();
+        AttachWebRendererInterop(jsRuntime, jsonOptions, jsComponentInterop);
     }
 
     /// <summary>
@@ -103,6 +100,44 @@ protected override void Dispose(bool disposing)
         base.Dispose(disposing);
     }
 
+    [UnconditionalSuppressMessage("Trimming", "IL2026:Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code", Justification = "<Pending>")]
+    private void AttachWebRendererInterop(IJSRuntime jsRuntime, JsonSerializerOptions jsonOptions, JSComponentInterop jsComponentInterop)
+    {
+        const string JSMethodIdentifier = "Blazor._internal.attachWebRendererInterop";
+
+        // These arguments should be kept in sync with WebRendererSerializerContext
+        object[] args = [
+            _rendererId,
+            _interopMethodsReference,
+            jsComponentInterop.Configuration.JSComponentParametersByIdentifier,
+            jsComponentInterop.Configuration.JSComponentIdentifiersByInitializer,
+        ];
+
+        if (jsRuntime is IInternalWebJSInProcessRuntime inProcessRuntime)
+        {
+            // Fast path for WebAssembly: Rather than using the JSRuntime to serialize
+            // parameters, we utilize the source-generated WebRendererSerializerContext
+            // for a faster JsonTypeInfo resolution.
+
+            // We resolve a JsonTypeInfo for DotNetObjectReference<WebRendererInteropMethods> from
+            // the JS runtime's JsonConverters. This is because adding DotNetObjectReference<T> as
+            // a supported type in the JsonSerializerContext generates unnecessary code to produce
+            // JsonTypeInfo for all the types referenced by both DotNetObjectReference<T> and its
+            // generic type argument.
+
+            var newJsonOptions = new JsonSerializerOptions(jsonOptions);
+            newJsonOptions.TypeInfoResolverChain.Clear();
+            newJsonOptions.TypeInfoResolverChain.Add(WebRendererSerializerContext.Default);
+            newJsonOptions.TypeInfoResolverChain.Add(JsonConverterFactoryTypeInfoResolver<DotNetObjectReference<WebRendererInteropMethods>>.Instance);
+            var argsJson = JsonSerializer.Serialize(args, newJsonOptions);
+            inProcessRuntime.InvokeJS(JSMethodIdentifier, argsJson, JSCallResultType.JSVoidResult, 0);
+        }
+        else
+        {
+            jsRuntime.InvokeVoidAsync(JSMethodIdentifier, args).Preserve();
+        }
+    }
+
     /// <summary>
     /// A collection of JS invokable methods that the JS-side code can use when it needs to
     /// make calls in the context of a particular renderer. This object is never exposed to
@@ -145,3 +180,11 @@ public void RemoveRootComponent(int componentId)
             => _jsComponentInterop.RemoveRootComponent(componentId);
     }
 }
+
+// This should be kept in sync with the argument types in the call to
+// 'Blazor._internal.attachWebRendererInterop'
+[JsonSerializable(typeof(object[]))]
+[JsonSerializable(typeof(int))]
+[JsonSerializable(typeof(Dictionary<string, JSComponentConfigurationStore.JSComponentParameter[]>))]
+[JsonSerializable(typeof(Dictionary<string, List<string>>))]
+internal sealed partial class WebRendererSerializerContext : JsonSerializerContext;

src/Components/WebAssembly/WebAssembly.Authentication/test/WebAssemblyAuthenticationServiceCollectionExtensionsTests.cs

@@ -12,12 +12,10 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Authentication;
 
 public class WebAssemblyAuthenticationServiceCollectionExtensionsTests
 {
-    private static readonly JsonSerializerOptions JsonOptions = new();
-
     [Fact]
     public void CanResolve_AccessTokenProvider()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         builder.Services.AddApiAuthorization();
         var host = builder.Build();
 
@@ -27,7 +25,7 @@ public void CanResolve_AccessTokenProvider()
     [Fact]
     public void CanResolve_IRemoteAuthenticationService()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         builder.Services.AddApiAuthorization();
         var host = builder.Build();
 
@@ -37,7 +35,7 @@ public void CanResolve_IRemoteAuthenticationService()
     [Fact]
     public void ApiAuthorizationOptions_ConfigurationDefaultsGetApplied()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         builder.Services.AddApiAuthorization();
         var host = builder.Build();
 
@@ -71,7 +69,7 @@ public void ApiAuthorizationOptions_ConfigurationDefaultsGetApplied()
     [Fact]
     public void ApiAuthorizationOptionsConfigurationCallback_GetsCalledOnce()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         var calls = 0;
         builder.Services.AddApiAuthorization(options =>
         {
@@ -98,7 +96,7 @@ public void ApiAuthorizationOptionsConfigurationCallback_GetsCalledOnce()
     [Fact]
     public void ApiAuthorizationTestAuthenticationState_SetsUpConfiguration()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         var calls = 0;
         builder.Services.AddApiAuthorization<TestAuthenticationState>(options => calls++);
 
@@ -124,7 +122,7 @@ public void ApiAuthorizationTestAuthenticationState_SetsUpConfiguration()
     [Fact]
     public void ApiAuthorizationTestAuthenticationState_NoCallback_SetsUpConfiguration()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         builder.Services.AddApiAuthorization<TestAuthenticationState>();
 
         var host = builder.Build();
@@ -147,7 +145,7 @@ public void ApiAuthorizationTestAuthenticationState_NoCallback_SetsUpConfigurati
     [Fact]
     public void ApiAuthorizationCustomAuthenticationStateAndAccount_SetsUpConfiguration()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         var calls = 0;
         builder.Services.AddApiAuthorization<TestAuthenticationState, TestAccount>(options => calls++);
 
@@ -173,7 +171,7 @@ public void ApiAuthorizationCustomAuthenticationStateAndAccount_SetsUpConfigurat
     [Fact]
     public void ApiAuthorizationTestAuthenticationStateAndAccount_NoCallback_SetsUpConfiguration()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         builder.Services.AddApiAuthorization<TestAuthenticationState, TestAccount>();
 
         var host = builder.Build();
@@ -196,7 +194,7 @@ public void ApiAuthorizationTestAuthenticationStateAndAccount_NoCallback_SetsUpC
     [Fact]
     public void ApiAuthorizationOptions_DefaultsCanBeOverriden()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         builder.Services.AddApiAuthorization(options =>
         {
             options.AuthenticationPaths.LogInPath = "a";
@@ -247,7 +245,7 @@ public void ApiAuthorizationOptions_DefaultsCanBeOverriden()
     [Fact]
     public void OidcOptions_ConfigurationDefaultsGetApplied()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         builder.Services.Replace(ServiceDescriptor.Singleton<NavigationManager, TestNavigationManager>());
         builder.Services.AddOidcAuthentication(options => { });
         var host = builder.Build();
@@ -286,7 +284,7 @@ public void OidcOptions_ConfigurationDefaultsGetApplied()
     [Fact]
     public void OidcOptions_DefaultsCanBeOverriden()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         builder.Services.AddOidcAuthentication(options =>
         {
             options.AuthenticationPaths.LogInPath = "a";
@@ -348,7 +346,7 @@ public void OidcOptions_DefaultsCanBeOverriden()
     [Fact]
     public void AddOidc_ConfigurationGetsCalledOnce()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         var calls = 0;
 
         builder.Services.AddOidcAuthentication(options => calls++);
@@ -365,7 +363,7 @@ public void AddOidc_ConfigurationGetsCalledOnce()
     [Fact]
     public void AddOidc_CustomState_SetsUpConfiguration()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         var calls = 0;
 
         builder.Services.AddOidcAuthentication<TestAuthenticationState>(options => options.ProviderOptions.Authority = (++calls).ToString(CultureInfo.InvariantCulture));
@@ -387,7 +385,7 @@ public void AddOidc_CustomState_SetsUpConfiguration()
     [Fact]
     public void AddOidc_CustomStateAndAccount_SetsUpConfiguration()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
         var calls = 0;
 
         builder.Services.AddOidcAuthentication<TestAuthenticationState, TestAccount>(options => options.ProviderOptions.Authority = (++calls).ToString(CultureInfo.InvariantCulture));
@@ -409,7 +407,7 @@ public void AddOidc_CustomStateAndAccount_SetsUpConfiguration()
     [Fact]
     public void OidcProviderOptionsAndDependencies_NotResolvedFromRootScope()
     {
-        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods(), JsonOptions);
+        var builder = new WebAssemblyHostBuilder(new TestInternalJSImportMethods());
 
         var calls = 0;
 

src/Components/WebAssembly/WebAssembly/src/Hosting/WebAssemblyHost.cs

@@ -227,6 +227,6 @@ private static void AddWebRootComponents(WebAssemblyRenderer renderer, RootCompo
                 operation.Descriptor!.Parameters));
         }
 
-        WebAssemblyRenderer.NotifyEndUpdateRootComponents(operationBatch.BatchId);
+        renderer.NotifyEndUpdateRootComponents(operationBatch.BatchId);
     }
 }