From 095fe1d339fcd0af350814566ec1ac245192f872 Mon Sep 17 00:00:00 2001
From: Yohta Kimura <kitakita7617@gmail.com>
Date: Thu, 22 Dec 2022 01:21:13 +0900
Subject: [PATCH] fix flatten

---
 src/Type/TypeCombinator.php | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/Type/TypeCombinator.php b/src/Type/TypeCombinator.php
index 142184dd5f5..ca6682034bc 100644
--- a/src/Type/TypeCombinator.php
+++ b/src/Type/TypeCombinator.php
@@ -209,10 +209,11 @@ public static function union(Type ...$types): Type
 		}
 
 		if ($scalarTypes !== []) {
-			if (count($scalarTypes) === 1) {
-				$types[] = $scalarTypes[array_key_first($scalarTypes)][0];
+			$flattenTypes = array_merge(...array_values($scalarTypes));
+			if (count($flattenTypes) === 1) {
+				$types[] = $flattenTypes[0];
 			} else {
-				$types[] = new UnionType(array_merge(...array_values($scalarTypes)), true);
+				$types[] = new UnionType($flattenTypes, true);
 			}
 		}