test.php

<?php

function should_return_array_or_nothing1() {
	return false;
}

function should_return_array_or_nothing2() {
	return null;
}

var_dump((array) should_return_array_or_nothing1());
// array(1) { [0]=> bool(false) }

var_dump((array) should_return_array_or_nothing2());
// array(0) { }