- ok(!$@, "wizard retrieve error ($@)");
- ok(defined $wiz2, 'retrieved wizard is defined');
- ok(ref $wiz2 eq 'SCALAR', 'retrieved wizard is a scalar ref');
- ok($sig == getsig $wiz2, 'retrieved wizard signature is correct');
+ is($@, '', 'wizard retreive doesn\'t croak');
+ ok(defined $wiz2, 'retrieved wizard is defined');
+ is(ref $wiz2, 'SCALAR', 'retrieved wizard is a scalar ref');
+ is($sig, getsig $wiz2, 'retrieved wizard signature is correct');
+
+ my $wiz3 = eval { wizard sig => [ ] };
+ like($@, qr/Invalid\s+numeric\s+signature\s+at\s+\Q$0\E/, 'non numeric signature croaks');
+ is($wiz3, undef, 'non numeric signature doesn\'t return anything');