1--TEST-- 2__debugInfo can declare union return type 3--FILE-- 4<?php 5class UnionType { 6 public function __debugInfo(): array|null {} 7} 8 9class UnionType2 { 10 public function __debugInfo(): null|array {} 11} 12 13class UnionTypeOldStyle { 14 public function __debugInfo(): ?array {} 15} 16 17class JustAnArray { 18 public function __debugInfo(): array {} 19} 20 21echo 'No problems!'; 22?> 23--EXPECT-- 24No problems! 25