TDD vs. Regular Expressions - coding kata

TimeValidator.php

<?php

class TimeValidator
{
	public function isValid($time_specification)
	{
		return 1 == preg_match($this->buildRegExp(), $time_specification);
	}

	private function buildRegExp()
	{
		$minutes = '([0-5][0-9])';

		$hours_less_than_24 = '([0-1][0-9]|2[0-3])';
		$time_spec_24 = "$hours_less_than_24:$minutes";

		$hours_less_than13 = '(0[1-9]|1[012])';
		$ampm = '( [AP]M)';
		$time_spec_12 = "$hours_less_than13:$minutes$ampm";

		$time_specification_matcher = "/^($time_spec_24|$time_spec_12)\$/D";

		return $time_specification_matcher;
	}
}

?>

TimeValidatorTest.php

<?php

require_once 'TimeValidator.php';

class TimeValidatorTest extends PHPUnit_Framework_TestCase
{
	public function setUp()
	{
		$this->validator = new TimeValidator();
	}

	/**
	 * @dataProvider provideValidTimeSpecifications
	 */
	public function testValidTimeSpecificationsAreAccepted($time_specification)
	{
		$this->assertTrue($this->validator->isValid($time_specification));
	}

	public function provideValidTimeSpecifications()
	{
		return array(
			'24 hour time specification' => array('10:42'),
			'12 hour time specification in the morning' => array('10:42 AM'),
			'12 hour time specification in the afternoon' => array('10:42 PM'),
			'12 hour time specification with leading zero' => array('01:42 PM'),
			'24 hour time specification with leading zero' => array('00:42'),
			'First minute of a 24 hour specification' => array('00:00'),
			'First minute of a 12 hour specification' => array('01:00 AM'),
			'Last 12 hour time specification in the morning' => array('12:59 AM'),
			'Last 12 hour time specification in the afternoon' => array('12:59 PM'),
			'Last 24 hour time specification' => array('23:59'),
		);
	}

	/**
	 * @dataProvider provideInvalidTimeSpecifications
	 */
	public function testInvalidTimeSpecificationsAreNotAccepted($time_specification)
	{
		$this->assertFalse($this->validator->isValid($time_specification));
	}

	public function provideInvalidTimeSpecifications()
	{
		return array(
			'Time specification must contain at least one colon' => array('1042'),
			'Time specification must contain at most one colon' => array('10::42'),
			'Time specification must not contain colon after minutes' => array('10:42:'),
			'Hours must be numeric' => array('ab:42'),
			'Hours must be less than 24' => array('24:42'),
			'Minutes must be numeric' => array('10:ab'),
			'Minutes must be less than 60' => array('10:60'),
			'Hours must be two-digit' => array('1:42'),
			'Minutes must be two-digit' => array('10:4'),
			'12 hour format must end with AM or PM' => array('10:42 XY'),
			'24 hour format must be exactly 5 characters long' => array('14:42 PM'),
			'Hour part of 12 hour format must be less than 13' => array('13:00 PM'),
			'12 hour format must be exactly 8 characters long' => array('12:45  AM'),
			'Multiline strings are not accepted' => array("10:42\n"),
			'12 hour time specification does not allow hours to be zero' => array('00:42 PM'),
		);
	}

	private $validator;
}

?>