HotChocolate GraphQL error when child-list is null

Question

given this query

{
  name,
  userList {
    firstName,
    lastName
  }
}

if userList (which is a list) is null for one object out of hundreds, I end up with this error Value cannot be null. (Parameter 'source'). Shouldn't the GraphQL engine detect the null and just ignore it?

I've tried making the userList property nullable, but that doesn't help.

Here's the stack trace of the error:

at System.Linq.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument)\r\n   
at System.Linq.Enumerable.Select[TSource,TResult](IEnumerable`1 source, Func`2 selector)\r\n   
at lambda_method961(Closure, OrganizationResponse)\r\n   
at System.Linq.Enumerable.SelectIPartitionIterator`2.GetCount(Boolean onlyIfCheap)\r\n   
at System.Linq.EnumerableExecutor`1.Execute()\r\n   
at System.Linq.EnumerableQuery`1.System.Linq.IQueryProvider.Execute[TElement](Expression expression)\r\n   
at HotChocolate.Types.Pagination.QueryableOffsetPagingHandler`1.<>c__DisplayClass3_0.<ResolveAsync>b__0()\r\n   
at System.Threading.Tasks.Task`1.InnerInvoke()\r\n   
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)\r\n
--- End of stack trace from previous location ---\r\n   
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)\r\n   
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)\r\n
--- End of stack trace from previous location ---\r\n  
at HotChocolate.Types.Pagination.QueryableOffsetPagingHandler`1.ResolveAsync(IResolverContext context, IQueryable`1 source, OffsetPagingArguments arguments, CancellationToken cancellationToken)\r\n   
at HotChocolate.Types.Pagination.OffsetPagingHandler.HotChocolate.Types.Pagination.IPagingHandler.SliceAsync(IResolverContext context, Object source)\r\n   
at HotChocolate.Types.Pagination.PagingMiddleware.InvokeAsync(IMiddlewareContext context)\r\n   
at HotChocolate.Utilities.MiddlewareCompiler`1.ExpressionHelper.AwaitTaskHelper(Task task)\r\n   
at HotChocolate.Execution.Processing.Tasks.ResolverTask.ExecuteResolverPipelineAsync(CancellationToken cancellationToken)\r\n   
at HotChocolate.Execution.Processing.Tasks.ResolverTask.TryExecuteAsync(CancellationToken cancellationToken)

Answer 1

This is solved by not using [UseProjection] on the operation. Especially since this is a REST call to another API, not a call to a database.