I want each integration test to create a unique database filename and delete it at the end of the test.

using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);
var constr = $"DataSource={Guid.NewGuid()}.db";
builder.Services.AddDbContext<AppDbContext>(o => o.UseSqlite(constr));
var app = builder.Build();
app.Run();

public record Person(int Id);
public class AppDbContext(DbContextOptions<AppDbContext> o) : DbContext(o)
{
    public DbSet<Person> People { get; set; }
}
public interface IWebApiMarker;

In order to ease switching between DisposeAsync() and Dispose(), I created a compilation variable SYNC.

#define SYNC
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.Extensions.DependencyInjection;

namespace WebApi.Test;

public class Test_1 : BaseTest
{
    [Fact] public async Task Test() => await Task.Delay(2000);
}

#if SYNC
public abstract class BaseTest : IDisposable
#else
public abstract class BaseTest : IAsyncDisposable
#endif
{
    private readonly WebApplicationFactory<IWebApiMarker> _factory;
    protected BaseTest()
    {
        _factory = new WebApplicationFactory<IWebApiMarker>();
        using var scope = _factory.Services.CreateScope();
        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
        db.Database.EnsureCreated();
    }
#if SYNC
    public void Dispose()
    {
        using var scope = _factory.Services.CreateScope();
        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
        db.Database.EnsureDeleted();
        _factory.Dispose();
    }
#else
    public async ValueTask DisposeAsync()
    {
        using var scope = _factory.Services.CreateScope();
        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
        db.Database.EnsureDeleted();
        await _factory.DisposeAsync();
    }
#endif
}

I don’t understand why DisposeAsync() fails to delete the database file at the end of each test.