wp/tests/phpunit/tests/formatting/Zeroise.php

<?php

/**
 * @group formatting
 */
class Tests_Formatting_Zeroise extends WP_UnitTestCase {
	function test_pads_with_leading_zeroes() {
		$this->assertEquals("00005", zeroise(5, 5));
	}

	function test_does_nothing_if_input_is_already_longer() {
		$this->assertEquals("5000000", zeroise(5000000, 2));
	}
}