add test for fixed bug 8555

It was fixed by fixing union(int, int<null, -1>, int<1, null>) = int.

Author: schlndh

tests/PHPStan/Rules/Comparison/BooleanAndConstantConditionRuleTest.php

@@ -433,4 +433,10 @@ public function testBug5365(): void
 		$this->analyse([__DIR__ . '/data/bug-5365.php'], []);
 	}
 
+	public function testBug8555(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->analyse([__DIR__ . '/data/bug-8555.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Comparison/data/bug-8555.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Bug8555;
+
+/**
+ * @return array<string, int|null>
+ */
+function test(int $first, int $second): array
+{
+	return [
+		'test' => $first && $second ? $first : null,
+		'test2' => $first && $second ? $first : null,
+	];
+}

tests/PHPStan/Type/TypeCombinatorTest.php

@@ -1577,6 +1577,15 @@ public function dataUnion(): iterable
 				IntegerRangeType::class,
 				'int<4, 81>',
 			],
+			[
+				[
+					new IntegerType(),
+					IntegerRangeType::fromInterval(null, -1),
+					IntegerRangeType::fromInterval(1, null),
+				],
+				IntegerType::class,
+				'int',
+			],
 			[
 				[
 					IntegerRangeType::fromInterval(1, 3),