UseProjections in Combination with BindMember throws Exception

[BickelLukas]

Is there an existing issue for this?

• [X] I have searched the existing issues

Describe the bug

Model

class Item
{
    public string Subject { get; set; }
    public string User { get; set; }
}

class User 
{
    public string Username { get; set; }
}

Query

class Query 
{
    [UseOffsetPaging]
    [UseProjection]
    public IQueryable<Item> GetItems(IAsyncDocumentSession session)
    {
        return session.Query<Item>();
    }
}

Type Extension

[ExtendObjectType(typeof(Item))]
public class ItemTypeExtension
{
    [BindMember(nameof(Item.User))]
    public async Task<User> GetUser([Parent] Item item,  IAsyncDocumentSession session)
        => await session.LoadAsync<User>(item.User);
}

---

When querying for items and the projection visitor throws an exception when the user is queried: The follwing works

query {
  items {
    subject
  }
}

This throws the following exception Property 'System.String Username' is not defined for type 'System.String' (Parameter 'property')

query {
  items {
    subject
    user {
      username
    }
  }
}

Steps to reproduce

https://github.com/glen-84/hc-5054 (.NET 8, HC 14.0.0-rc.1)

1. Use the above code and execute the query

Relevant log output

at System.Linq.Expressions.Expression.Property(Expression expression, PropertyInfo property)
   at HotChocolate.Data.Projections.Expressions.Handlers.QueryableProjectionScalarHandler.TryHandleLeave(QueryableProjectionContext context, ISelection selection, ISelectionVisitorAction& action)
   at HotChocolate.Data.Projections.ProjectionVisitor`1.Leave(ISelection selection, TContext context)
   at HotChocolate.Data.Projections.SelectionVisitor`1.Visit(ISelection selection, TContext context)
   at HotChocolate.Data.Projections.ProjectionVisitor`1.Visit(ISelection selection, TContext context)
   at HotChocolate.Data.Projections.SelectionVisitor`1.VisitObjectType(IOutputField field, ObjectType objectType, SelectionSetNode selectionSet, TContext context)
   at HotChocolate.Data.Projections.Expressions.QueryableProjectionVisitor.VisitObjectType(IOutputField field, ObjectType objectType, SelectionSetNode selectionSet, QueryableProjectionContext context)
   at HotChocolate.Data.Projections.SelectionVisitor`1.VisitChildren(IOutputField field, TContext context)
   at HotChocolate.Data.Projections.SelectionVisitor`1.Visit(IOutputField field, TContext context)
   at HotChocolate.Data.Projections.ProjectionVisitor`1.Visit(IOutputField field, TContext context)
   at HotChocolate.Data.Projections.SelectionVisitor`1.VisitChildren(ISelection selection, TContext context)
   at HotChocolate.Data.Projections.SelectionVisitor`1.Visit(ISelection selection, TContext context)
   at HotChocolate.Data.Projections.ProjectionVisitor`1.Visit(ISelection selection, TContext context)
   at HotChocolate.Data.Projections.SelectionVisitor`1.VisitObjectType(IOutputField field, ObjectType objectType, SelectionSetNode selectionSet, TContext context)
   at HotChocolate.Data.Projections.Expressions.QueryableProjectionVisitor.VisitObjectType(IOutputField field, ObjectType objectType, SelectionSetNode selectionSet, QueryableProjectionContext context)
   at HotChocolate.Data.Projections.SelectionVisitor`1.VisitChildren(IOutputField field, TContext context)
   at HotChocolate.Data.Projections.SelectionVisitor`1.Visit(IOutputField field, TContext context)
   at HotChocolate.Data.Projections.ProjectionVisitor`1.Visit(IOutputField field, TContext context)
   at HotChocolate.Data.Projections.ProjectionVisitor`1.Visit(TContext context)
   at HotChocolate.Data.Projections.Expressions.QueryableProjectionProvider.<>c__5`1.<CreateApplicatorAsync>b__5_0(IResolverContext context, Object input)
   at HotChocolate.Data.Projections.Expressions.QueryableProjectionProvider.<>c__DisplayClass4_0`1.<<CreateExecutor>g__ExecuteAsync|1>d.MoveNext()
--- End of stack trace from previous location ---
   at HotChocolate.Types.Pagination.PagingMiddleware.InvokeAsync(IMiddlewareContext context)
   at HotChocolate.Utilities.MiddlewareCompiler`1.ExpressionHelper.AwaitTaskHelper(Task task)
   at HotChocolate.AspNetCore.Authorization.AuthorizeMiddleware.InvokeAsync(IDirectiveContext context)
   at HotChocolate.Utilities.MiddlewareCompiler`1.ExpressionHelper.AwaitTaskHelper(Task task)
   at HotChocolate.Execution.Processing.Tasks.ResolverTask.ExecuteResolverPipelineAsync(CancellationToken cancellationToken)
   at HotChocolate.Execution.Processing.Tasks.ResolverTask.TryExecuteAsync(CancellationToken cancellationToken)

Additional Context?

After some investigation I found out the Problem is in the ProjectionVisitor. It is trying to assign a User object to the User Property of the Item which is a string.

Product

Hot Chocolate

Version

12.7.0 and also 13.0.0-preview.19

[BickelLukas]

bump

[rkotenko]

I am trying to use this exact scenario and have encountered the same issue. I would like to see a fix as well.

[rkotenko]

Is there any plan to deal with this? It becoming a big issue for us as we need to rename many model fields.

[brianbarenbaum]

Bump. Any update on this? Thanks!