OK, try adding something like
use FindBin;
use Test::More tests => 3;
use Test::Exception;
dies_ok { 'DupEventChecker'->new } 'dir_name not provided';
my $checker = 'DupEventChecker'->new(dir_name => $FindBin::Bin);
isa_ok $checker, 'DupEventChecker';
my ($itself) = grep { 0 <= index $0, $_ } $checker->dir->read;
ok $itself, 'test script found';
BTW, dir_name is required, but it isn't apparent from the declaration. dir could also have a default (e.g. '.', Cwd::getcwd or File::HomeDir->my_home).
Update: Example added to the BTW. Update 2: The example was improved.
($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,
|