#!/usr/bin/perl
use strict;
use helper;
#...
open(MYFILE, 'testcases.txt');
@HELPER::testCaseStack = <MYFILE>;
close(MYFILE);
foreach my $testCase (@testCaseStack) {
    undef %TESTCASE::; ##(1)##
    my $result = do($testCase); ##(2)##
    # do sth. with the result here
    next;

    EXIT_TESTCASE: ##(3)##
    # do sth. here
    next;

    EXIT_TESTRUNNER: ##(3)##
    # do sth. here
    last;
}