SeedTestData.cs

public class SeedTestDataTestBaseModule : AbpModule
{
    private static readonly SemaphoreSlim Semaphore = new SemaphoreSlim(1, 1);

    public override void OnApplicationInitialization(ApplicationInitializationContext context)
    {
        SeedTestData(context);
    }

    private static void SeedTestData(ApplicationInitializationContext context)
    {
        using (Semaphore.Lock())
        {
            AsyncHelper.RunSync(async () =>
            {
                using (var scope = context.ServiceProvider.CreateScope())
                {
                    await scope.ServiceProvider
                        .GetRequiredService<IDataSeeder>()
                        .SeedAsync();
                }
            });
        }
    }
}