UoW.EF.cs

        /// <summary>
        /// This test verifies that UoW commits changes in a transaction.
        /// Test is carried on by:
        ///     - running a transaction with exclusive lock on table LastUpdatingLog with the base.SqlConnection
        ///     - running the sut.Update (which opens another write transaction)
        ///     - execute SELECTs using another connection (with NoLock for checking uncommitted values)
        /// The sut can commit its transaction only after first transaction is committed
        /// </summary>
        [Fact]
        public void should_save_in_transaction()
        {
            var builder = new ContainerBuilder();
            builder.RegisterModule<IocUoWTestModule>();

            var container = builder.Build();
            using var lf = container.BeginLifetimeScope();
            var sut = lf.Resolve<Updater>();

            SqlConnection.Open();
            using var transaction = SqlConnection.BeginTransaction();
            SqlConnection.Execute("SELECT 1 FROM LastUpdatingLog WITH (TABLOCKX)", transaction: transaction); // creates an exclusive lock on table LastUpdatingLog
            SqlConnection.Execute("INSERT INTO LastUpdatingLog (Id) VALUES(17)", transaction: transaction);

            //sut is run asynchronously, so that tests can be run before transactions are committed
            var t = new Task(() => sut.Update("foo", 42));
            t.Start();

            using var tmpConn = new SqlConnection(LocalDbConnectionString.DbConnectionString);
            //First transaction inserted the initial value, but uncommitted
            var logIdNoLock = tmpConn.Query<int>("SELECT Id FROM LastUpdatingLog(NoLock)").Single();
            logIdNoLock.Should().Be(17);
            //No values are committed
            var logId = tmpConn.Query<int?>("SELECT Id FROM LastUpdatingLog").SingleOrDefault();
            logId.Should().BeNull();
            //sut still has not committed the customer
            var customer = tmpConn.Query<MacCustomer>("SELECT * FROM Customer").SingleOrDefault();
            customer.Should().BeNull();

            //Commit transaction with exclusive lock, then waits for the sut to complete the task
            transaction.Commit();
            t.Wait();

            //Final values are those inserted by sut
            logId = tmpConn.Query<int>("SELECT Id FROM LastUpdatingLog").SingleOrDefault();
            logId.Should().Be(42);
            customer = tmpConn.Query<MacCustomer>("SELECT * FROM Customer").Single();
            customer.Number.Should().Be("foo");
        }