Line.php

<?php

namespace Wj\Stoffer\Scissors;

class Line
{
    private $input;

    public function __construct($input)
    {
        $this->input = $input;
    }

    public function getSnippets()
    {
        $snippets = preg_split('/(\R)/', $this->input, -1, \PREG_SPLIT_DELIM_CAPTURE);
        $return = array();
        do {
            $return[] = current($snippets).next($snippets);
        } while (false !== next($snippets));

        return $return;
    }
}

LineSpec.php

<?php

namespace spec\Wj\Stoffer\Scissors;

use PhpSpec\ObjectBehavior;

class LineSpec extends ObjectBehavior
{
    function it_is_initializable()
    {
        $this->shouldHaveType('Wj\Stoffer\Scissors');
    }

    function it_cuts_a_string_in_lines()
    {
        $this->beConstructedWith("Hello World\nLorem\nIpsum\nDolor");

        $this->getSnippets()->shouldBe(array(
            "Hello World\n",
            "Lorem\n",
            "Ipsum\n",
            "Dolor"
        ));
    }

    function it_returns_empty_lines()
    {
        $this->getSnippets("Hello\n\nWorld")->shouldBe(array(
            "Hello\n",
            "\n",
            "World"
        ));
    }

    function it_returns_trailing_new_lines()
    {
        $this->getSnippets("Hello\nWorld\n")->shouldBe(array(
            "Hello\n",
            "World\n",
            ""
        ));
    }
}