Fixed ServiceKind.Resolver not working with ResolveWith (#5677) (#5678)

Author: tobias-tengler

src/HotChocolate/Core/src/Types/Types/Descriptors/ObjectFieldDescriptor.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
@@ -20,7 +21,7 @@ public class ObjectFieldDescriptor
     , IObjectFieldDescriptor
 {
     private bool _argumentsInitialized;
-    private readonly ParameterInfo[] _parameterInfos = Array.Empty<ParameterInfo>();
+    private ParameterInfo[] _parameterInfos = Array.Empty<ParameterInfo>();
 
     protected ObjectFieldDescriptor(
         IDescriptorContext context,
@@ -50,7 +51,9 @@ protected ObjectFieldDescriptor(
             MemberKind.ObjectField);
         Definition.Type = context.TypeInspector.GetOutputReturnTypeRef(member);
         Definition.SourceType = sourceType;
-        Definition.ResolverType = resolverType == sourceType ? null : resolverType;
+        Definition.ResolverType = resolverType == sourceType
+            ? null
+            : resolverType;
         Definition.IsParallelExecutable =
             context.Options.DefaultResolverStrategy is ExecutionStrategy.Parallel;
 
@@ -337,6 +340,21 @@ public IObjectFieldDescriptor ResolveWith(
             Definition.ResolverMember = propertyOrMethod;
             Definition.Resolver = null;
             Definition.ResultType = propertyOrMethod.GetReturnType();
+
+            if (propertyOrMethod is MethodInfo m)
+            {
+                _parameterInfos = m.GetParameters();
+
+                var parameters = new Dictionary<NameString, ParameterInfo>();
+
+                foreach (ParameterInfo parameterInfo in _parameterInfos)
+                {
+                    parameters.Add(new NameString(parameterInfo.Name!), parameterInfo);
+                }
+
+                Parameters = parameters;
+            }
+
             return this;
         }
 

src/HotChocolate/Core/src/Types/Types/Descriptors/OutputFieldDescriptorBase.cs

@@ -33,9 +33,12 @@ protected override void OnCreateDefinition(TDefinition definition)
     {
         base.OnCreateDefinition(definition);
 
-        foreach (ArgumentDescriptor argument in Arguments)
+        if (_arguments is not null)
         {
-            Definition.Arguments.Add(argument.CreateDefinition());
+            foreach (ArgumentDescriptor argument in Arguments)
+            {
+                Definition.Arguments.Add(argument.CreateDefinition());
+            }
         }
     }
 

src/HotChocolate/Core/test/Types.Tests/Resolvers/ResolverServiceTests.cs

@@ -1,6 +1,7 @@
 using System.Threading.Tasks;
 using HotChocolate.Execution;
 using HotChocolate.Tests;
+using HotChocolate.Types;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.ObjectPool;
 using Snapshooter.Xunit;
@@ -84,6 +85,32 @@ public async Task AddResolverService()
         await executor.ExecuteAsync("{ sayHello }").MatchSnapshotAsync();
     }
 
+    [Fact]
+    public async Task AddResolverService_2()
+    {
+        Snapshot.FullName();
+
+        var executor =
+            await new ServiceCollection()
+                .AddSingleton<SayHelloService>()
+                .AddGraphQL()
+                .AddQueryType<QueryType>()
+                .ModifyRequestOptions(o => o.IncludeExceptionDetails = true)
+                .BuildRequestExecutorAsync();
+
+        await executor.ExecuteAsync("{ sayHello }").MatchSnapshotAsync();
+    }
+
+    public class QueryType : ObjectType
+    {
+        protected override void Configure(IObjectTypeDescriptor descriptor)
+        {
+            descriptor
+                .Field("sayHello")
+                .ResolveWith<QueryResolverService>(r => r.SayHello(default!));
+        }
+    }
+
     public class SayHelloService
     {
         public string SayHello() => "Hello";

src/HotChocolate/Core/test/Types.Tests/Resolvers/__snapshots__/ResolverServiceTests.AddResolverService_2.snap

@@ -0,0 +1,5 @@
+{
+  "data": {
+    "sayHello": "Hello"
+  }
+}