fix union of int ranges

Author: schlndh

src/Type/TypeCombinator.php

@@ -37,6 +37,8 @@
 use function md5;
 use function sprintf;
 use function usort;
+use const PHP_INT_MAX;
+use const PHP_INT_MIN;
 
 /**
  * @api
@@ -185,6 +187,7 @@ public static function union(Type ...$types): Type
 		$scalarTypes = [];
 		$hasGenericScalarTypes = [];
 		$enumCaseTypes = [];
+		$integerRangeTypes = [];
 		for ($i = 0; $i < $typesCount; $i++) {
 			if ($types[$i] instanceof ConstantScalarType) {
 				$type = $types[$i];
@@ -212,6 +215,13 @@ public static function union(Type ...$types): Type
 				continue;
 			}
 
+			if ($types[$i] instanceof IntegerRangeType) {
+				$integerRangeTypes[] = $types[$i];
+				unset($types[$i]);
+
+				continue;
+			}
+
 			if (!$types[$i]->isArray()->yes()) {
 				continue;
 			}
@@ -225,6 +235,12 @@ public static function union(Type ...$types): Type
 		}
 
 		$enumCaseTypes = array_values($enumCaseTypes);
+		usort(
+			$integerRangeTypes,
+			static fn (IntegerRangeType $a, IntegerRangeType $b): int => ($a->getMin() ?? PHP_INT_MIN) <=> ($b->getMin() ?? PHP_INT_MIN)
+				?: ($a->getMax() ?? PHP_INT_MAX) <=> ($b->getMax() ?? PHP_INT_MAX)
+		);
+		$types = array_merge($types, $integerRangeTypes);
 		$types = array_values($types);
 		$typesCount = count($types);
 

tests/PHPStan/Type/TypeCombinatorTest.php

@@ -1558,6 +1558,25 @@ public function dataUnion(): iterable
 				UnionType::class,
 				'int<1, 3>|int<7, 9>',
 			],
+			[
+				[
+					IntegerRangeType::fromInterval(4, 9),
+					IntegerRangeType::fromInterval(16, 81),
+					IntegerRangeType::fromInterval(8, 27),
+				],
+				IntegerRangeType::class,
+				'int<4, 81>',
+			],
+			[
+				[
+					IntegerRangeType::fromInterval(8, 27),
+					IntegerRangeType::fromInterval(4, 6),
+					new ConstantIntegerType(7),
+					IntegerRangeType::fromInterval(16, 81),
+				],
+				IntegerRangeType::class,
+				'int<4, 81>',
+			],
 			[
 				[
 					IntegerRangeType::fromInterval(1, 3),