TodoQuery.cs

namespace Wanderlust.API.Presentation.Queries;

using HotChocolate.Types.Pagination;

[ExtendObjectType(OperationTypeNames.Query)]
[GraphQLName(nameof(TodoQuery))]
public class TodoQuery
{
    [UsePaging]
    public Connection<ITodoResult> GetTodos(string? after, int? first)
    {
        IEnumerable<ITodoResult> todos = new List<Todo>()
        {
            new Todo() { Id = "1" },
            new Todo() { Id = "2" },
        };

        var edges = todos.Select(todo => new Edge<ITodoResult>(todo, "1")).ToList();

        var pageInfo = new ConnectionPageInfo(false, false, null, null);

        var connection = new Connection<ITodoResult>(
            edges,
            pageInfo,
            ct => ValueTask.FromResult(0));

        return connection;
    }

    [UnionType("TodoResult")]
    public interface ITodoResult
    {
    }

    public class Todo : ITodoResult
    {
        public string Id { get; set; } = default!;
    }

    public class TodoError : ITodoResult
    {
        public string Message { get; set; } = "Error message here";
    }
}