dnspec4.php

<?php

namespace Dn;

class StringCalculatorSpec
{
    function specification()
    {
        return [
            'It is initializable' => function ($calculator)
            {
                $calculator->shouldHaveType('StringCalculator');
            },

            'It requires string input' => function ($calculator)
            {
                $calculator->shouldThrow('\InvalidArgumentException')->during('add', [null]);
            },

            'It adds 2 numbers separated by comma' => function ($calculator)
            {
                $calculator->add('1,2')->shouldReturn(3);
            },
        ];
    }
}