#!/usr/bin/env perl

use strict;
use warnings;

use constant {
    STR => 0,
    EXP => 1,
};

use Test::More;

my @tests = (
    ['1-2-3', '123'],
    ['-1-2-3', '-123'],
    ['1--2-3', ''],
    ['1-2--3', ''],
    ['1--2--3', ''],
    ['-1--2-3', ''],
    ['-1-2--3', ''],
    ['-1--2--3', ''],
    ['1-2-', ''],
    ['-1-2-', ''],
    ['garbage', ''],
    ['expect', 'failure'],
    ['-2-3-4', '-234'],
);

plan tests => 0+@tests;

my $re = qr{(?x:
    ^           # start of string
    (           # start capture X
        -?      # optional leading minus
        \d+     # 1 or more digits
    )           # end capture X
    -           # required hyphen
    (           # start capture Y
        \d+     # 1 or more digits
    )           # end capture Y
    -           # required hyphen
    (           # start capture Z
        \d+     # 1 or more digits
    )           # end capture Z
    $           # end of string
)};

for my $test (@tests) {
    my ($X, $Y, $Z, $got) = ('') x 4;

    if (($X, $Y, $Z) = $test->[STR] =~ $re) {
        $got = "$X$Y$Z";
    }

    ok($got eq $test->[EXP],
        "Testing '$test->[STR]' is "
        . (length $test->[EXP] ? 'GOOD' : 'BAD')
    );
}