non-optional groups cannot be null when PREG_UNMATCHED_AS_NULL

Author: staabm

src/Type/Php/RegexArrayShapeMatcher.php

@@ -253,12 +253,17 @@ private function buildArrayType(
 		$countGroups = count($captureGroups);
 		$i = 0;
 		foreach ($captureGroups as $captureGroup) {
+			$groupValueType = $valueType;
+
 			if (!$wasMatched->yes()) {
 				$optional = true;
 			} else {
 				if ($i < $countGroups - $trailingOptionals) {
 					$optional = false;
-				} elseif (($flags & PREG_UNMATCHED_AS_NULL) !== 0 && $this->phpVersion->supportsPregUnmatchedAsNull()) {
+					if ($this->containsUnmatchedAsNull($flags)) {
+						$groupValueType = TypeCombinator::removeNull($groupValueType);
+					}
+				} elseif ($this->containsUnmatchedAsNull($flags)) {
 					$optional = false;
 				} else {
 					$optional = $captureGroup->isOptional();
@@ -268,14 +273,14 @@ private function buildArrayType(
 			if ($captureGroup->isNamed()) {
 				$builder->setOffsetValueType(
 					$this->getKeyType($captureGroup->getName()),
-					$valueType,
+					$groupValueType,
 					$optional,
 				);
 			}
 
 			$builder->setOffsetValueType(
 				$this->getKeyType($i + 1),
-				$valueType,
+				$groupValueType,
 				$optional,
 			);
 
@@ -285,6 +290,11 @@ private function buildArrayType(
 		return $builder->getArray();
 	}
 
+	private function containsUnmatchedAsNull(int $flags): bool
+	{
+		return ($flags & PREG_UNMATCHED_AS_NULL) !== 0 && $this->phpVersion->supportsPregUnmatchedAsNull();
+	}
+
 	private function getKeyType(int|string $key): Type
 	{
 		if (is_string($key)) {
@@ -298,7 +308,7 @@ private function getValueType(int $flags): Type
 	{
 		$valueType = new StringType();
 		$offsetType = IntegerRangeType::fromInterval(0, null);
-		if (($flags & PREG_UNMATCHED_AS_NULL) !== 0 && $this->phpVersion->supportsPregUnmatchedAsNull()) {
+		if ($this->containsUnmatchedAsNull($flags)) {
 			$valueType = TypeCombinator::addNull($valueType);
 			// unmatched groups return -1 as offset
 			$offsetType = IntegerRangeType::fromInterval(-1, null);

tests/PHPStan/Analyser/nsrt/bug-11311.php

@@ -7,7 +7,7 @@
 function doFoo(string $s) {
 	if (1 === preg_match('/(?<major>\d+)\.(?<minor>\d+)(?:\.(?<patch>\d+))?/', $s, $matches, PREG_UNMATCHED_AS_NULL)) {
 
-		assertType('array{0: string, major: string|null, 1: string|null, minor: string|null, 2: string|null, patch: string|null, 3: string|null}', $matches);
+		assertType('array{0: string, major: string, 1: string, minor: string, 2: string, patch: string|null, 3: string|null}', $matches);
 	}
 }