+my $checkordersrs = [
+ [qw(COUNT)],
+ [2]
+];
+
+$dbh->{mock_add_resultset} = $checkordersrs;
+is(DelInvoice(42), undef, "Invoices with items don't get deleted");
+
+$checkordersrs = [
+ [qw(COUNT)],
+ [0]
+];
+
+my $deleters = [
+ [qw(COUNT)],
+ [1]
+];
+
+$dbh->{mock_add_resultset} = $checkordersrs;
+$dbh->{mock_add_resultset} = $deleters;
+ok(DelInvoice(42), "Invoices without items do get deleted");