How to use AppFixture with PostgreSqlContainer

BaseIntegrationTest.cs

namespace Solution.IntegrationTests;

public abstract class BaseIntegrationTest : TestBase<PostgresTestcontainer> { }

PostgresTestcontainerBase.cs

using Testcontainers.PostgreSql;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.TestHost;
using Microsoft.EntityFrameworkCore;
using Solution.Persistence;

namespace Solution.IntegrationTests;

public class PostgresTestcontainerBase : AppFixture<Program>
{
    private PostgreSqlContainer _postgreSqlContainer;

    protected override async Task PreSetupAsync()
    {
        _postgreSqlContainer = new PostgreSqlBuilder()
        .WithImage("postgres:latest")
        .WithDatabase("yourdbname")
        .WithUsername("postgres")
        .WithPassword("postgres")
        .Build();

        await _postgreSqlContainer.StartAsync();
    }

    protected override void ConfigureApp(IWebHostBuilder b)
    {
        b.ConfigureTestServices(services =>
            {
                var descriptor = services.SingleOrDefault(s => s.ServiceType == typeof(DbContextOptions<YourDbContext>));

                if(descriptor is not null) services.Remove(descriptor);

                services.AddDbContext<YourDbContext>(options =>
                {
                    // PersistenceExtension resebles the static class in your Projects for DI which includes the Migrations
                    options.UseNpgsql(_postgreSqlContainer.GetConnectionString(), npgsqlBuilder =>
                        npgsqlBuilder.MigrationsAssembly(typeof(PersistenceExtension).Assembly.GetName().Name));
                });
            }
        );
    }

    protected override async Task SetupAsync()
    {
        using var scope = Services.CreateScope();
        await using var dbContext = scope.ServiceProvider.GetRequiredService<YourDbContext>();
        await dbContext.Database.MigrateAsync();
    }
}

SomeIntegrationTests.cs

namespace Solution.IntegrationTests;

public class SomeIntegrationTests(PostgresTestcontainerBase _app) : BaseIntegrationTest
{
    [Fact]
    public async Task Some_Test()
    {   
        // ... 
    }
}