optionally callback after connect

This is useful if you want your handle to do something unusual after
connect, such as quiet warnings.

t/35-Pg-common.t

@@ -18,6 +18,12 @@ my ( $mdriver, $test_dsn, $test_user, $test_password );
     $test_password = 'testpass';
 }
 
+my $dbh;
+my $post_connect_cb = {
+    my $dbh = @_.shift;
+    $dbh.do('SET client_min_messages = warning');
+};
+
 # Detect and report possible errors from eval of the common test script
 warn $! if "ok 99-common.pl6" ne eval slurp 't/99-common.pl6';
 

t/99-common.pl6

@@ -18,6 +18,8 @@ ok $drh_version > 0, "MiniDBD::$mdriver version $drh_version"; # test 2
 my $dbh = MiniDBI.connect( $test_dsn, $test_user, $test_password, :RaiseError<1> );
 ok $dbh, "connect to $test_dsn"; # test 3
 
+eval '$post_connect_cb.($dbh)';
+
 # Test .prepare() and .execute() a few times while setting things up.
 # Drop a table of the same name so that the following create can work.
 my $sth = $dbh.prepare("DROP TABLE IF EXISTS nom");