Npgsql.Tests.TestUtil.GetUniqueIdentifier C# (CSharp) Method

        public static string GetUniqueIdentifier(string prefix)
            => prefix + Interlocked.Increment(ref _counter);

        public void FailConnectThenSucceed()
        {
            var dbName = TestUtil.GetUniqueIdentifier(nameof(FailConnectThenSucceed));

            using (var conn1 = OpenConnection())
            {
                conn1.ExecuteNonQuery($"DROP DATABASE IF EXISTS \"{dbName}\"");
                try
                {
                    var connString = new NpgsqlConnectionStringBuilder(ConnectionString)
                    {
                        Database = dbName,
                        Pooling  = false
                    }.ToString();

                    using (var conn2 = new NpgsqlConnection(connString))
                    {
                        Assert.That(() => conn2.Open(),
                                    Throws.Exception.TypeOf <PostgresException>()
                                    .With.Property(nameof(PostgresException.SqlState)).EqualTo("3D000") // database doesn't exist
                                    );
                        Assert.That(conn2.FullState, Is.EqualTo(ConnectionState.Closed));

                        conn1.ExecuteNonQuery($"CREATE DATABASE \"{dbName}\" TEMPLATE template0");

                        conn2.Open();
                        conn2.Close();
                    }
                }
                finally
                {
                    //conn1.ExecuteNonQuery($"DROP DATABASE IF EXISTS \"{dbName}\"");
                }
            }
        }