using System;
using System.Linq;

RuntimeState.Reset();

User? user = new()
{
    DBUser = new DBUser
    {
        ID = 1
    }
};

using IS0AUTTSTContext db = GetDbContext();

System.Collections.Generic.List<TestRun> list = db.TestRuns
    .Where(t => t.ID > 0 &&
                t.Definition!.Application!.Deleted == false)
    .ToList();

//List<int> apps = [];

if (user != null && user.IsInRole("Basic"))
{
    List<int> apps = [];

    System.Collections.Generic.List<ApplicationUser> appUsers =
        db.ApplicationUsers
          .Where(au => au.UserID == user.DBUser!.ID)
          .ToList();

    apps.AddRange(
        appUsers.Where(au => au != null)
                .Select(au => au.AppID)
                .ToList()
    );
}

Console.WriteLine("Done");

static IS0AUTTSTContext GetDbContext()
{
    return new IS0AUTTSTContext();
}

public static class RuntimeState
{
    public static bool RoleWasChecked { get; set; }

    public static void Reset()
    {
        RoleWasChecked = false;
    }
}

public sealed class IS0AUTTSTContext : IDisposable
{
    public System.Collections.Generic.List<TestRun> TestRuns { get; } =
    [
        new TestRun
        {
            ID = 1,
            Definition = new Definition
            {
                Application = new Application
                {
                    Deleted = false
                }
            }
        }
    ];

    public System.Collections.Generic.List<ApplicationUser> ApplicationUsers { get; } =
    [
        new ApplicationUser
        {
            UserID = 1,
            AppID = 101
        }
    ];

    public void Dispose()
    {
    }
}

public sealed class TestRun
{
    public int ID { get; set; }

    public Definition? Definition { get; set; }
}

public sealed class Definition
{
    public Application? Application { get; set; }
}

public sealed class Application
{
    public bool Deleted { get; set; }
}

public sealed class ApplicationUser
{
    public int UserID { get; set; }

    public int AppID { get; set; }
}

public sealed class User
{
    public DBUser? DBUser { get; set; }

    public bool IsInRole(string role)
    {
        RuntimeState.RoleWasChecked = true;
        return role == "Basic";
    }
}

public sealed class DBUser
{
    public int ID { get; set; }
}