use strict;
use warnings;
use Test::More;

my @expected = (
   [ 'abc',             'abc'  ],
   [ 'abc.bill.com',    'abc'  ],
   [ 'abc.bill.com.au', 'abc'  ],
   [ 'xy42.com',        'xy42' ],
   [ 'x_y.com',         'x_y'  ],
   [ 'x-y.com',         'x-y'  ],
   [ '',                ''     ],
   [ '.',               ''     ],
   [ 'a.',              'a'    ],
   [ '-.',              '-'    ],
   [ '_.',              '_'    ],
   [ '.a',              ''     ],
   [ 'f',               'f'    ],
   [ 'f.1',             'f'    ],
   [ 'f.1.2',           'f'    ],
   [ 'f.1.2.3',         'f'    ],
   [ 'f.1.2.3.4',       'f'    ],
   [ 'f.1.2.3.4.5',     'f'    ],
   [ 'f.1.2.3.4.5.67',  'f'    ],
   [ 'ABC.123.456',     'ABC'  ],
);

plan tests => scalar(@expected);

for my $e (@expected) {
   my ( $got, $exp ) = @{$e};
   $got =~ s/\..*$//;
   is( $got, $exp, "'$e->[0]'" . ' -> ' . "'$got'" );
}