Re: Enhance 'pg_createsubscriber' to retrieve databases automatically when no database is provided. - Mailing list pgsql-hackers

On Tue, 18 Mar 2025 at 17:34, Shubham Khanna
<khannashubham1197@gmail.com> wrote:
>
> I have added an additional test case to 040_pg_createsubscriber.pl as suggested.
>
> The attached patch contains the suggested changes.

How about we change the below code:
+# Verify that user databases (postgres, $db1, $db2) got subscriptions. Both
+# $db1 and $db2 must be escaped to pass the safe_psql(), but it is difficult.
+# Thus, we define a cursor, obtain a dbname from the instance and compere one
+# by one.
+my @user_dbs = ('postgres', $db1, $db2);
+
+my $bgconn = $node_u->background_psql('postgres');
+$bgconn->query_safe(
+       qq[
+       BEGIN;
+       DECLARE cursor CURSOR FOR SELECT datname FROM pg_subscription,
pg_database
+       WHERE subdbid = pg_database.oid and datistemplate = 'f'
+       ORDER BY pg_database.oid;
+]);
+
+# Fetch from the cursor three times and confirm the existence of the
+# subscription on $dbname
+foreach my $dbname (@user_dbs)
+{
+       my $result = $bgconn->query_safe("FETCH cursor;");
+
+       is($result, $dbname, "subscription is created on $dbname");
+}

like:
$result = $node_u->safe_psql($db1, 'SELECT datname FROM
pg_subscription, pg_database WHERE subdbid = pg_database.oid and
datistemplate = \'f\' ORDER BY pg_database.oid');
is($result, "postgres
$db1
$db2", 'subscription is created on the required databases');

I felt this might simplify your verification logic.

Regards,
Vignesh