Add IUserContextBuilder<TSchema>

README.md

@@ -894,6 +894,10 @@ are long-lived, using scoped services within a user context builder will result
 scoped services having a matching long lifetime.  You may wish to alleviate this by
 creating a service scope temporarily within your user context builder.
 
+For applications that service multiple schemas, you may register `IUserContextBuilder<TSchema>`
+to create a user context for a specific schema.  This is useful when you need to create
+a user context that is specific to a particular schema.
+
 ### Mutations within GET requests
 
 For security reasons and pursuant to current recommendations, mutation GraphQL requests

src/Transports.AspNetCore/GraphQLHttpMiddleware.cs

@@ -36,6 +36,15 @@ public GraphQLHttpMiddleware(
         : base(next, serializer, documentExecuter, serviceScopeFactory, options, hostApplicationLifetime)
     {
     }
+
+    /// <inheritdoc/>
+    protected override ValueTask<IDictionary<string, object?>?> BuildUserContextAsync(HttpContext context, object? payload)
+    {
+        var userContextBuilder = context.RequestServices.GetService<IUserContextBuilder<TSchema>>();
+        return userContextBuilder == null
+            ? base.BuildUserContextAsync(context, payload)
+            : userContextBuilder.BuildUserContextAsync(context, payload);
+    }
 }
 
 /// <summary>
@@ -677,17 +686,18 @@ protected virtual async Task<ExecutionResult> ExecuteRequestAsync(HttpContext co
     /// <see cref="IHttpContextAccessor"/> via <see cref="ExecutionOptions.RequestServices"/>
     /// if needed.
     /// <br/><br/>
-    /// By default this method pulls the registered <see cref="IUserContextBuilder"/>,
-    /// if any, within the service scope and executes it to build the user context.
+    /// By default this method pulls the registered <see cref="IUserContextBuilder{TSchema}"/>
+    /// or <see cref="IUserContextBuilder"/> instance, if any, within the service scope
+    /// and executes it to build the user context.
     /// In this manner, both scoped and singleton <see cref="IUserContextBuilder"/>
     /// instances are supported, although singleton instances are recommended.
     /// </summary>
-    protected virtual async ValueTask<IDictionary<string, object?>?> BuildUserContextAsync(HttpContext context, object? payload)
+    protected virtual ValueTask<IDictionary<string, object?>?> BuildUserContextAsync(HttpContext context, object? payload)
     {
         var userContextBuilder = context.RequestServices.GetService<IUserContextBuilder>();
         return userContextBuilder == null
-            ? null
-            : await userContextBuilder.BuildUserContextAsync(context, payload);
+            ? default // successful result of null
+            : userContextBuilder.BuildUserContextAsync(context, payload);
     }
 
     ValueTask<IDictionary<string, object?>?> IUserContextBuilder.BuildUserContextAsync(HttpContext context, object? payload)

src/Transports.AspNetCore/IUserContextBuilder.cs

@@ -24,3 +24,9 @@ public interface IUserContextBuilder
     /// <returns>Dictionary object representing user context. Return <see langword="null"/> to use default user context.</returns>
     ValueTask<IDictionary<string, object?>?> BuildUserContextAsync(HttpContext context, object? payload);
 }
+
+/// <inheritdoc cref="IUserContextBuilder"/>
+public interface IUserContextBuilder<TSchema> : IUserContextBuilder
+    where TSchema : ISchema
+{
+}

tests/ApiApprovalTests/net50+net60+netcoreapp31/GraphQL.Server.Transports.AspNetCore.approved.txt

@@ -145,6 +145,7 @@ namespace GraphQL.Server.Transports.AspNetCore
         where TSchema : GraphQL.Types.ISchema
     {
         public GraphQLHttpMiddleware(Microsoft.AspNetCore.Http.RequestDelegate next, GraphQL.IGraphQLTextSerializer serializer, GraphQL.IDocumentExecuter<TSchema> documentExecuter, Microsoft.Extensions.DependencyInjection.IServiceScopeFactory serviceScopeFactory, GraphQL.Server.Transports.AspNetCore.GraphQLHttpMiddlewareOptions options, Microsoft.Extensions.Hosting.IHostApplicationLifetime hostApplicationLifetime) { }
+        protected override System.Threading.Tasks.ValueTask<System.Collections.Generic.IDictionary<string, object?>?> BuildUserContextAsync(Microsoft.AspNetCore.Http.HttpContext context, object? payload) { }
     }
     public sealed class HttpGetValidationRule : GraphQL.Validation.IValidationRule
     {
@@ -166,6 +167,8 @@ namespace GraphQL.Server.Transports.AspNetCore
     {
         System.Threading.Tasks.ValueTask<System.Collections.Generic.IDictionary<string, object?>?> BuildUserContextAsync(Microsoft.AspNetCore.Http.HttpContext context, object? payload);
     }
+    public interface IUserContextBuilder<TSchema> : GraphQL.Server.Transports.AspNetCore.IUserContextBuilder
+        where TSchema : GraphQL.Types.ISchema { }
     public class UserContextBuilder<TUserContext> : GraphQL.Server.Transports.AspNetCore.IUserContextBuilder
         where TUserContext : System.Collections.Generic.IDictionary<string, object?>
     {

tests/ApiApprovalTests/netcoreapp21+netstandard20/GraphQL.Server.Transports.AspNetCore.approved.txt

@@ -152,6 +152,7 @@ namespace GraphQL.Server.Transports.AspNetCore
         where TSchema : GraphQL.Types.ISchema
     {
         public GraphQLHttpMiddleware(Microsoft.AspNetCore.Http.RequestDelegate next, GraphQL.IGraphQLTextSerializer serializer, GraphQL.IDocumentExecuter<TSchema> documentExecuter, Microsoft.Extensions.DependencyInjection.IServiceScopeFactory serviceScopeFactory, GraphQL.Server.Transports.AspNetCore.GraphQLHttpMiddlewareOptions options, GraphQL.Server.Transports.AspNetCore.IHostApplicationLifetime hostApplicationLifetime) { }
+        protected override System.Threading.Tasks.ValueTask<System.Collections.Generic.IDictionary<string, object?>?> BuildUserContextAsync(Microsoft.AspNetCore.Http.HttpContext context, object? payload) { }
     }
     public class HostApplicationLifetime : GraphQL.Server.Transports.AspNetCore.IHostApplicationLifetime, Microsoft.Extensions.Hosting.IHostedService
     {
@@ -184,6 +185,8 @@ namespace GraphQL.Server.Transports.AspNetCore
     {
         System.Threading.Tasks.ValueTask<System.Collections.Generic.IDictionary<string, object?>?> BuildUserContextAsync(Microsoft.AspNetCore.Http.HttpContext context, object? payload);
     }
+    public interface IUserContextBuilder<TSchema> : GraphQL.Server.Transports.AspNetCore.IUserContextBuilder
+        where TSchema : GraphQL.Types.ISchema { }
     public class UserContextBuilder<TUserContext> : GraphQL.Server.Transports.AspNetCore.IUserContextBuilder
         where TUserContext : System.Collections.Generic.IDictionary<string, object?>
     {

tests/Transports.AspNetCore.Tests/Middleware/MiscTests.cs

@@ -32,6 +32,37 @@ public void Constructors()
         _ = new GraphQLHttpMiddleware(next, serializer, executer, scopeFactory, options, appLifetime);
     }
 
+    [Fact]
+    public async Task SchemaSpecificBuilders()
+    {
+        var middleware = new MyMiddleware<Schema>(
+            Mock.Of<RequestDelegate>(MockBehavior.Strict),
+            Mock.Of<IGraphQLTextSerializer>(MockBehavior.Strict),
+            Mock.Of<IDocumentExecuter<Schema>>(MockBehavior.Strict),
+            Mock.Of<IServiceScopeFactory>(MockBehavior.Strict),
+            new GraphQLHttpMiddlewareOptions(),
+            Mock.Of<IHostApplicationLifetime>(MockBehavior.Strict));
+        var builder = new Mock<IUserContextBuilder<Schema>>(MockBehavior.Strict);
+        var d = new Dictionary<string, object?> { { "test", "test" } };
+        builder.Setup(x => x.BuildUserContextAsync(It.IsAny<HttpContext>(), It.IsAny<object?>())).ReturnsAsync(d);
+        var serviceProviderMock = new Mock<IServiceProvider>(MockBehavior.Strict);
+        serviceProviderMock.Setup(x => x.GetService(typeof(IUserContextBuilder<Schema>))).Returns(builder.Object);
+        var contextMock = new Mock<HttpContext>(MockBehavior.Strict);
+        contextMock.Setup(x => x.RequestServices).Returns(serviceProviderMock.Object);
+        (await middleware.MyBuildUserContextAsync(contextMock.Object, null)).ShouldBe(d);
+    }
+
+    private class MyMiddleware<TSchema> : GraphQLHttpMiddleware<TSchema>
+        where TSchema : ISchema
+    {
+        public MyMiddleware(RequestDelegate next, IGraphQLTextSerializer serializer, IDocumentExecuter<TSchema> executer, IServiceScopeFactory scopeFactory, GraphQLHttpMiddlewareOptions options, IHostApplicationLifetime hostApplicationLifetime)
+            : base(next, serializer, executer, scopeFactory, options, hostApplicationLifetime)
+        {
+        }
+
+        public ValueTask<IDictionary<string, object?>?> MyBuildUserContextAsync(HttpContext context, object? payload) => base.BuildUserContextAsync(context, payload);
+    }
+
     [Fact]
     public async Task WriteErrorResponseString()
     {