use strict;
use warnings;
use TAP::Harness;
use TAP::Parser::Aggregator 3.01;

#...

sub get_harness {
    return TAP::Harness->new({
            verbosity   => -2,
            exec        => ['../../parrot', '-G', 'perl6.pbc'],
            merge       => 1,
    });
}

# ...
# find a file to process, which will be stored in $test:

my $H = get_harness();
my $agg = TAP::Parser::Aggregator->new();
$agg->start();
$H->aggregate_tests($agg, $test);
$agg->stop();
my $actually_passed = $agg->passed - $agg->skipped - $agg->todo;
# more statistics collection here...