graphql-aspnet · kevin-carroll · Mar 10, 2024 · Mar 10, 2024
diff --git a/src/.editorconfig b/src/.editorconfig
@@ -197,7 +197,7 @@ dotnet_naming_style.begins_with_i.word_separator =
 dotnet_naming_style.begins_with_i.capitalization = pascal_case


-
-
 [*.{cs,vb}]
-dotnet_style_prefer_compound_assignment=true:suggestion
+dotnet_style_prefer_compound_assignment=true:suggestion
+
+file_header_template = *************************************************************\n project:  graphql-aspnet\n --\n repo: https://github.com/graphql-aspnet\n docs: https://graphql-aspnet.github.io\n --\n License:  MIT\n *************************************************************
diff --git a/src/graphql-aspnet/Internal/Resolvers/InputValueResolverMethodGenerator.cs b/src/graphql-aspnet/Internal/Resolvers/InputValueResolverMethodGenerator.cs
@@ -46,7 +46,7 @@ public InputValueResolverMethodGenerator(ISchema schema)
        public IInputValueResolver CreateResolver(GraphTypeExpression typeExpression)
        {
            // used for variable definitions
-            return this.CreateResolver(typeExpression, null);
+            return this.CreateResolverInternal(typeExpression, null);
        }

        /// <summary>
@@ -57,7 +57,7 @@ public IInputValueResolver CreateResolver(GraphTypeExpression typeExpression)
        /// <returns>IQueryInputValueResolver.</returns>
        public IInputValueResolver CreateResolver(IInputGraphField field)
        {
-            return this.CreateResolver(field.TypeExpression, field);
+            return this.CreateResolverInternal(field.TypeExpression, field);
        }

        /// <summary>
@@ -68,22 +68,28 @@ public IInputValueResolver CreateResolver(IInputGraphField field)
        /// <returns>IQueryInputValueResolver.</returns>
        public IInputValueResolver CreateResolver(IGraphArgument argument)
        {
-            return this.CreateResolver(argument.TypeExpression, argument);
+            return this.CreateResolverInternal(argument.TypeExpression, argument);
        }

-        private IInputValueResolver CreateResolver(GraphTypeExpression typeExpression, IDefaultValueSchemaItem defaultValueProvider)
+        private IInputValueResolver CreateResolverInternal(GraphTypeExpression typeExpression, IDefaultValueSchemaItem defaultValueProvider)
        {
            Validation.ThrowIfNull(typeExpression, nameof(typeExpression));

            var graphType = _schema.KnownTypes.FindGraphType(typeExpression.TypeName);
            if (graphType == null)
                return null;

-            return this.CreateResolver(graphType, typeExpression, defaultValueProvider);
+            return this.CreateResolverInternal(graphType, typeExpression, defaultValueProvider);
        }

-        private IInputValueResolver CreateResolver(IGraphType graphType, GraphTypeExpression expression, IDefaultValueSchemaItem defaultValueProvider)
+        private IInputValueResolver CreateResolverInternal(IGraphType graphType, GraphTypeExpression expression, IDefaultValueSchemaItem defaultValueProvider, Dictionary<IInputObjectGraphType, IInputValueResolver> trackedComplexResolvers = null)
        {
+            // keep a list of complex value resolvers that were generated in this run
+            // to prevent infinite loops for self referencing objects
+            // all instnaces where a complex object needs to be resolved will use
+            // the same referenced resolver, scoped to this single argument that is being generated
+            trackedComplexResolvers = trackedComplexResolvers ?? new Dictionary<IInputObjectGraphType, IInputValueResolver>();
+
            // extract the core resolver for the input type being processed
            IInputValueResolver coreResolver = null;
            Type coreType = null;
@@ -101,7 +107,7 @@ private IInputValueResolver CreateResolver(IGraphType graphType, GraphTypeExpres
            else if (graphType is IInputObjectGraphType inputType)
            {
                coreType = _schema.KnownTypes.FindConcreteType(inputType);
-                coreResolver = this.CreateInputObjectResolver(inputType, coreType, defaultValueProvider);
+                coreResolver = this.CreateInputObjectResolver(inputType, coreType, defaultValueProvider, trackedComplexResolvers);
            }

            // wrap any list wrappers around core resolver according to the type expression
@@ -117,23 +123,22 @@ private IInputValueResolver CreateResolver(IGraphType graphType, GraphTypeExpres
            return coreResolver;
        }

-        private IInputValueResolver CreateInputObjectResolver(IInputObjectGraphType inputType, Type type, IDefaultValueSchemaItem defaultValueProvider)
+        private IInputValueResolver CreateInputObjectResolver(
+            IInputObjectGraphType inputType,
+            Type type,
+            IDefaultValueSchemaItem defaultValueProvider,
+            Dictionary<IInputObjectGraphType, IInputValueResolver> trackedComplexResolvers)
        {
+            if (trackedComplexResolvers.TryGetValue(inputType, out var alreadyBuiltResolver))
+                return alreadyBuiltResolver;
+
            var inputObjectResolver = new InputObjectValueResolver(inputType, type, _schema, defaultValueProvider);
+            trackedComplexResolvers.Add(inputType, inputObjectResolver);

            foreach (var field in inputType.Fields)
            {
-                IInputValueResolver childResolver;
-                if (field.TypeExpression.TypeName == inputType.Name)
-                {
-                    childResolver = inputObjectResolver;
-                }
-                else
-                {
-                    var graphType = _schema.KnownTypes.FindGraphType(field.TypeExpression.TypeName);
-                    childResolver = this.CreateResolver(graphType, field.TypeExpression, field);
-                }
-
+                var graphType = _schema.KnownTypes.FindGraphType(field.TypeExpression.TypeName);
+                var childResolver = this.CreateResolverInternal(graphType, field.TypeExpression, field, trackedComplexResolvers);
                inputObjectResolver.AddFieldResolver(field.Name, childResolver);
            }


diff --git a/src/unit-tests/graphql-aspnet-tests/Execution/GeneralQueryExecutionTests3.cs b/src/unit-tests/graphql-aspnet-tests/Execution/GeneralQueryExecutionTests3.cs
@@ -45,5 +45,50 @@ public async Task Record_asInputObject_RendersObjectCorrectly()
            var result = await server.RenderResult(builder);
            CommonAssertions.AreEqualJsonStrings(expectedOutput, result);
        }
+
+        [Test]
+        public async Task Self_Referencing_Nested_List_Input()
+        {
+            var server = new TestServerBuilder()
+                  .AddGraphQL(o =>
+                  {
+                      o.AddType<SelfReferencingInputObjectController>();
+                      o.ResponseOptions.ExposeExceptions = true;
+                  })
+                .Build();
+
+            // totalPeople exists on  base controller
+            // totalEmployees exists on  the added EmployeeController
+            var builder = server.CreateQueryContextBuilder()
+                .AddQueryText(@"query {
+                    countNestings(item: 
+                        {
+                            name: ""root"",
+                            children: [
+                                {
+                                    name: ""child1"",
+                                    children: [
+                                        { name: ""child1.1""},
+                                        {name: ""child1.2""}
+                                    ]
+                                },
+                                {name: ""child2""}
+                            ]
+                        })
+                 }");
+
+            var expectedOutput =
+                @"{
+                    ""data"": {
+                       ""countNestings"" :  5
+                    }
+                }";
+
+            var result = await server.ExecuteQuery(builder);
+            Assert.AreEqual(0, result.Messages.Count);
+
+            var renderedResult = await server.RenderResult(builder);
+            CommonAssertions.AreEqualJsonStrings(expectedOutput, renderedResult);
+        }
    }
 }
diff --git a/...aphql-aspnet-tests/Execution/TestData/ExecutionPlanTestData/SelfReferencingInputObject.cs b/...aphql-aspnet-tests/Execution/TestData/ExecutionPlanTestData/SelfReferencingInputObject.cs
@@ -0,0 +1,20 @@
+// *************************************************************
+//  project:  graphql-aspnet
+//  --
+//  repo: https://github.com/graphql-aspnet
+//  docs: https://graphql-aspnet.github.io
+//  --
+//  License:  MIT
+//  *************************************************************
+
+namespace GraphQL.AspNet.Tests.Execution.TestData.ExecutionPlanTestData
+{
+    using System.Collections.Generic;
+
+    public class SelfReferencingInputObject
+    {
+        public string Name { get; set; }
+
+        public IEnumerable<SelfReferencingInputObject> Children { get; set; }
+    }
+}
diff --git a/...et-tests/Execution/TestData/ExecutionPlanTestData/SelfReferencingInputObjectController.cs b/...et-tests/Execution/TestData/ExecutionPlanTestData/SelfReferencingInputObjectController.cs
@@ -0,0 +1,38 @@
+// *************************************************************
+//  project:  graphql-aspnet
+//  --
+//  repo: https://github.com/graphql-aspnet
+//  docs: https://graphql-aspnet.github.io
+//  --
+//  License:  MIT
+//  *************************************************************
+
+namespace GraphQL.AspNet.Tests.Execution.TestData.ExecutionPlanTestData
+{
+    using System.Collections.Generic;
+    using GraphQL.AspNet.Attributes;
+    using GraphQL.AspNet.Controllers;
+
+    public class SelfReferencingInputObjectController : GraphController
+    {
+        [QueryRoot]
+        public int CountNestings(SelfReferencingInputObject item)
+        {
+            var i = 0;
+            var stack = new Stack<SelfReferencingInputObject>();
+            stack.Push(item);
+            while (stack.Count > 0)
+            {
+                var curItem = stack.Pop();
+                i++;
+                if (curItem.Children != null)
+                {
+                    foreach (var child in curItem.Children)
+                        stack.Push(child);
+                }
+            }
+
+            return i;
+        }
+    }
+}