HotChocolate code-first triple-nested array throws SchemaException

Product

Hot Chocolate

Version

15.1.10

Link to minimal reproduction

https://github.com/denys-vynohradov-saltykov/hot-chocolate-nested-list-error-poc

Steps to reproduce

1. Create web project with package references HotChocolate.AspNetCore and HotChocolate.Types.Analyzers
2. Query.cs:

[QueryType]
public class Query
{
    [GraphQLName("coordinates")]
    [GraphQLType<NonNullType<ListType<NonNullType<ListType<NonNullType<ListType<FloatType>>>>>>>]
    public double[][][] GetCoordinates()
    {
        return
        [
            [
                [
                    10d,
                    20d
                ]
            ]
        ];
    }
}

2. Program.cs:

var builder = WebApplication.CreateBuilder(args);

builder.AddGraphQL()
    .InitializeOnStartup()
    .AddPoCTypes();

var app = builder.Build();

app.MapGraphQL("/graphql", schemaName: null);
app.MapGraphQLSchema("/graphql/schema");

app.Run();

4. Run project

What is expected?

• Project started successfully
• when you navigate into /graphql/ -> schema -> SDL you should see schema

type Query {
  coordinates: [[[Float!]!]!]!
}

What is actually happening?

Exception is thrown

HotChocolate.SchemaException: For more details look at the `Errors` property.

1. Unable to resolve type reference `ListType<ListType<ListType<FloatType>!>!>!`. (HotChocolate.Types.ObjectType)

   at HotChocolate.Configuration.RegisteredType.GetType[T](TypeReference typeRef)
   at HotChocolate.Types.OutputFieldBase.OnCompleteField(ITypeCompletionContext context, ITypeSystemMember declaringMember, OutputFieldDefinitionBase definition)
   at HotChocolate.Types.OutputFieldBase.OnCompleteField(ITypeCompletionContext context, ITypeSystemMember declaringMember, FieldDefinitionBase definition)
   at HotChocolate.Types.FieldBase.CompleteField(ITypeCompletionContext context, ITypeSystemMember declaringMember)
   at HotChocolate.Types.FieldBase.HotChocolate.Types.Helpers.IFieldCompletion.CompleteField(ITypeCompletionContext context, ITypeSystemMember declaringMember)
   at HotChocolate.Internal.FieldInitHelper.CompleteFieldsInternal[TField](ITypeCompletionContext context, ITypeSystemMember declaringMember, TField[] fields)
   at HotChocolate.Internal.FieldInitHelper.CompleteFieldsInternal[TFieldDefinition,TField](ITypeCompletionContext context, ITypeSystemMember declaringMember, IEnumerable`1 fieldDefinitions, Func`3 fieldFactory, Int32 fieldCount)
   at HotChocolate.Internal.FieldInitHelper.CompleteFields[TFieldDefinition,TField](ITypeCompletionContext context, ITypeSystemMember declaringMember, IReadOnlyList`1 fieldDefs, Func`3 fieldFactory)
   at HotChocolate.Types.ObjectType.OnCompleteFields(ITypeCompletionContext context, ObjectTypeDefinition definition)
   at HotChocolate.Types.ObjectType.OnCompleteType(ITypeCompletionContext context, ObjectTypeDefinition definition)
   at HotChocolate.Types.TypeSystemObjectBase`1.CompleteType(ITypeCompletionContext context)
   at HotChocolate.Configuration.TypeInitializer.CompleteType(RegisteredType registeredType)
   at HotChocolate.Configuration.TypeInitializer.<CompleteTypes>b__33_0(RegisteredType type)
   at HotChocolate.Configuration.TypeInitializer.ProcessTypes(TypeDependencyFulfilled fulfilled, Func`2 action)
   at HotChocolate.Configuration.TypeInitializer.CompleteTypes()
   at HotChocolate.Configuration.TypeInitializer.Initialize()
   at HotChocolate.SchemaBuilder.Setup.InitializeTypes(SchemaBuilder builder, IDescriptorContext context, IReadOnlyList`1 types)
   at HotChocolate.SchemaBuilder.Setup.Create(SchemaBuilder builder, LazySchema lazySchema, IDescriptorContext context)
   at HotChocolate.SchemaBuilder.Create(IDescriptorContext context)
   at HotChocolate.SchemaBuilder.HotChocolate.ISchemaBuilder.Create(IDescriptorContext context)
   at HotChocolate.Execution.RequestExecutorResolver.CreateSchemaAsync(ConfigurationContext context, RequestExecutorSetup setup, RequestExecutorOptions executorOptions, IServiceProvider schemaServices, TypeModuleChangeMonitor typeModuleChangeMonitor, CancellationToken cancellationToken)
   at HotChocolate.Execution.RequestExecutorResolver.CreateSchemaServicesAsync(ConfigurationContext context, RequestExecutorSetup setup, TypeModuleChangeMonitor typeModuleChangeMonitor, CancellationToken cancellationToken)
   at HotChocolate.Execution.RequestExecutorResolver.CreateRequestExecutorAsync(String schemaName, Boolean isInitialCreation, CancellationToken cancellationToken)
   at HotChocolate.Execution.RequestExecutorResolver.GetRequestExecutorAsync(String schemaName, CancellationToken cancellationToken)
   at HotChocolate.Execution.RequestExecutorResolver.<WarmupAsync>g__WarmupSchemaAsync|40_0(String schemaName, CancellationToken cancellationToken)
   at HotChocolate.Execution.RequestExecutorResolver.WarmupAsync(CancellationToken cancellationToken)
   at HotChocolate.AspNetCore.Warmup.RequestExecutorWarmupService.StartAsync(CancellationToken cancellationToken)
   at Microsoft.Extensions.Hosting.Internal.Host.<StartAsync>b__14_1(IHostedService service, CancellationToken token)
   at Microsoft.Extensions.Hosting.Internal.Host.ForeachService[T](IEnumerable`1 services, CancellationToken token, Boolean concurrent, Boolean abortOnFirstException, List`1 exceptions, Func`3 operation)
   at Microsoft.Extensions.Hosting.Internal.Host.StartAsync(CancellationToken cancellationToken)
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.Run(IHost host)
   at Program.<Main>$(String[] args)

Relevant log output

Additional context

There is a hardcoded limit to how many nested lists HotChocolate allows
https://github.com/ChilliCream/graphql-platform/blob/ce7a74a2edb7f0a66dd6cd84dedd39492c3a8782/src/HotChocolate/Core/src/Types/Internal/TypeInfo.cs#L185

Why do we need triple-nested arrays in the schema:

• to introduce subset of GeoJSON standard into the schema. GeoJSON Polygon coordinates is an array of array of array.
  https://datatracker.ietf.org/doc/html/rfc7946#section-3.1.6
• HotChocolate.Data.Spatial is overkill since we do not need most of the types provided in the package

Known workaround is to introduce custom scalar that represents float array

"""
Array of floating point numbers
For example: [3.14, 2.7]
"""
scalar Position

type Query {
  coordinates: [[Position!]!]!
}

Start with the linked minimal reproduction and inspect TypeInfo.cs around line 185, where the hardcoded nested-list limit is noted. Run the reproduction with HotChocolate 15.1.10 and confirm the SchemaException for the triple-nested array. Done means the project starts and the schema exposes coordinates as [[[Float!]!]!]! without the exception.