Hot Chocolate throws error when Flags Enum is in a paged response

Product

Hot Chocolate

Version

15.1.3

Link to minimal reproduction

https://github.com/cabillin/hot-chocolate-issues/tree/flag_enum_incorrect_handling

Steps to reproduce

query bob {
  parents(first: 1) {
    nodes {
      childId
      id
      flags {
        isANA
      }
    }
  }
}

What is expected?

{
  "data": {
    "parents": {
      "nodes": [
        {
          "childId": "Child1",
          "id": 1,
          "flags": {
            "isANA": false
          }
        }
      ]
    }
  }
}

What is actually happening?

{
  "errors": [
    {
      "message": "Unexpected Execution Error",
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "path": [
        "parents"
      ],
      "extensions": {
        "message": "Property 'Int32 Count' is not defined for type 'HotChocolate.Issues.Classes.FlagEnum' (Parameter 'property')",
        "stackTrace": "   at System.Linq.Expressions.Expression.Property(Expression expression, PropertyInfo property)\r\n   at HotChocolate.Execution.Projections.SelectionExpressionBuilder.BuildAssignmentExpression(PropertyNode node, Context context)\r\n   at HotChocolate.Execution.Projections.SelectionExpressionBuilder.BuildSelectionSetExpression(Context context, TypeNode parent)\r\n   at HotChocolate.Execution.Projections.SelectionExpressionBuilder.BuildTypeSwitchExpression(Context context, TypeContainer parent)\r\n   at HotChocolate.Execution.Projections.SelectionExpressionBuilder.BuildAssignmentExpression(PropertyNode node, Context context)\r\n   at HotChocolate.Execution.Projections.SelectionExpressionBuilder.BuildSelectionSetExpression(Context context, TypeNode parent)\r\n   at HotChocolate.Execution.Projections.SelectionExpressionBuilder.BuildTypeSwitchExpression(Context context, TypeContainer parent)\r\n   at HotChocolate.Execution.Projections.SelectionExpressionBuilder.BuildExpression[TRoot](ISelection selection)\r\n   at HotChocolate.Execution.Processing.HotChocolateExecutionSelectionExtensions.<>c__2`1.<GetOrCreateExpression>b__2_0(String _, ValueTuple`2 ctx)\r\n   at HotChocolate.Execution.Processing.Operation.GetOrAddState[TState,TContext](String key, Func`3 createState, TContext context)\r\n   at HotChocolate.Execution.Processing.HotChocolateExecutionSelectionExtensions.GetOrCreateExpression[TValue](ISelection selection)\r\n   at HotChocolate.Execution.Processing.HotChocolateExecutionSelectionExtensions.AsSelector[TValue](ISelection selection)\r\n   at HotChocolate.Data.QueryContextParameterExpressionBuilder.CreateQueryContext[T](IResolverContext context)\r\n   at lambda_method3(Closure, IResolverContext)\r\n   at HotChocolate.Types.Helpers.FieldMiddlewareCompiler.<>c__DisplayClass9_0.<<CreateResolverMiddleware>b__0>d.MoveNext()\r\n--- End of stack trace from previous location ---\r\n   at HotChocolate.Types.UnwrapFieldMiddlewareHelper.<>c__DisplayClass0_1.<<CreateDataMiddleware>b__1>d.MoveNext()\r\n--- End of stack trace from previous location ---\r\n   at HotChocolate.Types.Pagination.PagingMiddleware.InvokeAsync(IMiddlewareContext context)\r\n   at HotChocolate.Execution.Processing.Tasks.ResolverTask.ExecuteResolverPipelineAsync(CancellationToken cancellationToken)\r\n   at HotChocolate.Execution.Processing.Tasks.ResolverTask.TryExecuteAsync(CancellationToken cancellationToken)"
      }
    }
  ],
  "data": {
    "parents": null
  }
}

Additional Context

query bob {
  parents(first: 1) {
    nodes {
      childId
      id
    }
  }
}

works

query bob {
  parents(first: 2, where: { flags: { eq: { isANA: true } } }) {
    nodes {
      childId
      id
    }
  }
}

returns successfully, but I'm not sure if it is working correctly. I would have expected to get back id 3 and id 5, but I only get back id 3

Reproduce the failure using the linked minimal reproduction and the paged GraphQL query. Start with the stack-traced SelectionExpressionBuilder.BuildAssignmentExpression path and inspect how the flags enum is projected before PagingMiddleware runs. Done means the paged response returns the expected isANA value without an execution error, and the reported flags filter returns the expected records.