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'" );
}

##</code><code>##

1..20
ok 1 - 'abc' -> 'abc'
ok 2 - 'abc.bill.com' -> 'abc'
ok 3 - 'abc.bill.com.au' -> 'abc'
ok 4 - 'xy42.com' -> 'xy42'
ok 5 - 'x_y.com' -> 'x_y'
ok 6 - 'x-y.com' -> 'x-y'
ok 7 - '' -> ''
ok 8 - '.' -> ''
ok 9 - 'a.' -> 'a'
ok 10 - '-.' -> '-'
ok 11 - '_.' -> '_'
ok 12 - '.a' -> ''
ok 13 - 'f' -> 'f'
ok 14 - 'f.1' -> 'f'
ok 15 - 'f.1.2' -> 'f'
ok 16 - 'f.1.2.3' -> 'f'
ok 17 - 'f.1.2.3.4' -> 'f'
ok 18 - 'f.1.2.3.4.5' -> 'f'
ok 19 - 'f.1.2.3.4.5.67' -> 'f'
ok 20 - 'ABC.123.456' -> 'ABC'