1--TEST-- 2Returned null, expected array reference 3--FILE-- 4<?php 5function &foo(array &$in) : array { 6 return null; 7} 8 9$array = [1, 2, 3]; 10var_dump(foo($array)); 11?> 12--EXPECTF-- 13Fatal error: Uncaught TypeError: foo(): Return value must be of type array, null returned in %s:%d 14Stack trace: 15#0 %s(%d): foo(Array) 16#1 {main} 17 thrown in %s on line %d 18