fix: discriminate proxies in GetResourceContext

Author: mrnkr

src/JsonApiDotNetCore/Internal/ResourceGraph.cs

@@ -4,6 +4,7 @@
 using System.Linq.Expressions;
 using JsonApiDotNetCore.Internal.Contracts;
 using JsonApiDotNetCore.Models;
+using Castle.DynamicProxy;
 
 namespace JsonApiDotNetCore.Internal
 {
@@ -26,7 +27,9 @@ public ResourceContext GetResourceContext(string resourceName)
             => Resources.SingleOrDefault(e => e.ResourceName == resourceName);
         /// <inheritdoc />
         public ResourceContext GetResourceContext(Type resourceType)
-            => Resources.SingleOrDefault(e => e.ResourceType == resourceType) ?? Resources.SingleOrDefault(e => e.ResourceType.IsAssignableFrom(resourceType));
+            => IsDynamicProxy(resourceType) ?
+                Resources.SingleOrDefault(e => e.ResourceType == resourceType.BaseType) :
+                Resources.SingleOrDefault(e => e.ResourceType == resourceType);
         /// <inheritdoc />
         public ResourceContext GetResourceContext<TResource>() where TResource : class, IIdentifiable
             => GetResourceContext(typeof(TResource));
@@ -125,6 +128,11 @@ private IEnumerable<IResourceField> Getter<T>(Expression<Func<T, dynamic>> selec
                 $"For example: 'article => article.Title' or 'article => new {{ article.Title, article.PageCount }}'.");
         }
 
+        private bool IsDynamicProxy(Type resourceType)
+        {
+            return typeof(IProxyTargetAccessor).IsAssignableFrom(resourceType);
+        }
+
         private static Expression RemoveConvert(Expression expression)
             => expression is UnaryExpression unaryExpression
                && unaryExpression.NodeType == ExpressionType.Convert

src/JsonApiDotNetCore/JsonApiDotNetCore.csproj

@@ -22,6 +22,7 @@
 
   <ItemGroup>
     <PackageReference Include="Ben.Demystifier" Version="0.1.6" />
+    <PackageReference Include="Castle.Core" Version="4.4.1" />
     <PackageReference Include="Humanizer" Version="2.7.9" />
     <PackageReference Include="Microsoft.EntityFrameworkCore" Version="$(EFCoreVersion)" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />

test/UnitTests/Internal/ResourceGraphBuilder_Tests.cs

@@ -1,11 +1,11 @@
-using System;
 using JsonApiDotNetCore.Builders;
 using JsonApiDotNetCore.Configuration;
 using JsonApiDotNetCore.Internal;
 using JsonApiDotNetCore.Models;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
+using Castle.DynamicProxy;
 using Xunit;
 
 namespace UnitTests.Internal
@@ -50,16 +50,18 @@ public void GetResourceContext_Yields_Right_Type_For_Proxy()
             var resourceGraphBuilder = new ResourceGraphBuilder(new JsonApiOptions(), NullLoggerFactory.Instance);
             resourceGraphBuilder.AddResource<Bar>();
             var resourceGraph = (ResourceGraph)resourceGraphBuilder.Build();
+            var proxyGenerator = new ProxyGenerator();
 
             // Act
-            var result = resourceGraph.GetResourceContext(typeof(DummyProxy));
+            var proxy = proxyGenerator.CreateClassProxy<Bar>();
+            var result = resourceGraph.GetResourceContext(proxy.GetType());
 
             // Assert
             Assert.Equal(typeof(Bar), result.ResourceType);
         }
 
         [Fact]
-        public void GetResourceContext_Yields_Right_Type_For_IIdentifiable()
+        public void GetResourceContext_Yields_Right_Type_For_Identifiable()
         {
             // Arrange
             var resourceGraphBuilder = new ResourceGraphBuilder(new JsonApiOptions(), NullLoggerFactory.Instance);
@@ -80,10 +82,7 @@ private class TestContext : DbContext
             public DbSet<Foo> Foos { get; set; }
         }
 
-        private class Bar : Identifiable { }
-
-        // Used to simulate a lazy loading proxy
-        private class DummyProxy : Bar { }
+        public class Bar : Identifiable { }
 
     }