Strings::matchAll() cannot return null

Author: ondrejmirtes

src/Type/Nette/StringsMatchAllDynamicReturnTypeExtension.php

@@ -8,10 +8,8 @@
 use PHPStan\Reflection\MethodReflection;
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\DynamicStaticMethodReturnTypeExtension;
-use PHPStan\Type\NullType;
 use PHPStan\Type\Php\RegexArrayShapeMatcher;
 use PHPStan\Type\Type;
-use PHPStan\Type\TypeCombinator;
 
 class StringsMatchAllDynamicReturnTypeExtension implements DynamicStaticMethodReturnTypeExtension
 {
@@ -48,12 +46,7 @@ public function getTypeFromStaticMethodCall(MethodReflection $methodReflection,
 			$flagsType = $scope->getType($flagsArg->value);
 		}
 
-		$arrayShape = $this->regexArrayShapeMatcher->matchAllExpr($patternArg->value, $flagsType, TrinaryLogic::createYes(), $scope);
-		if ($arrayShape === null) {
-			return null;
-		}
-
-		return TypeCombinator::union($arrayShape, new NullType());
+		return $this->regexArrayShapeMatcher->matchAllExpr($patternArg->value, $flagsType, TrinaryLogic::createYes(), $scope);
 	}
 
 }

tests/Type/Nette/data/strings-match.php

@@ -26,10 +26,10 @@ function (string $s): void {
 
 function (string $s): void {
 	$result = Strings::matchAll($s, '/ab(?P<num>\d+)(?P<suffix>ab)?/', PREG_SET_ORDER);
-	assertType("list<array{0: string, num: numeric-string, 1: numeric-string, suffix?: non-empty-string, 2?: non-empty-string}>|null", $result);
+	assertType("list<array{0: string, num: numeric-string, 1: numeric-string, suffix?: non-empty-string, 2?: non-empty-string}>", $result);
 };
 
 function (string $s): void {
 	$result = Strings::matchAll($s, '/ab(?P<num>\d+)(?P<suffix>ab)?/', PREG_PATTERN_ORDER);
-	assertType("array{0: list<string>, num: list<numeric-string>, 1: list<numeric-string>, suffix: list<string>, 2: list<string>}|null", $result);
+	assertType("array{0: list<string>, num: list<numeric-string>, 1: list<numeric-string>, suffix: list<string>, 2: list<string>}", $result);
 };