#!usr/bin/env perl

use strict;
use warnings;
use List::Util 'uniq';

sub do_thing {
    my ($file_path, $href) = @_;

    open my $fh, '<', $file_path or return 0;

    while (my $line = <$fh>) {

        # stuff

        my $group = 'some setup for this line.';
        my $value = 'some setup for this line.';

        push @{$href->{test}}, {
            group   => $group,
            values  => [
                $value,
                sort uniq(@{$href->{values} // []}), # This will be empty if the definedness test would have been false.
            ],
        };
    }
}