test.pl

use Mojo::Pg;
use Mojolicious::Lite;

my $pg = Mojo::Pg->new('postgresql://tester:testing@/test');

Mojo::IOLoop->next_tick(sub {
  $pg->pubsub->listen(test => sub {
    my ($pubsub, $payload) = @_;
    app->log->debug("TEST: $payload");
  });
});

Mojo::IOLoop->recurring(3 => sub {
  $pg->pubsub->notify(test => time);
});

app->start;