Refactor RegexExpressionHelper

Author: staabm

src/Rules/Regexp/RegularExpressionQuotingRule.php

@@ -15,23 +15,25 @@
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
 use PHPStan\ShouldNotHappenException;
-use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\Php\RegexExpressionHelper;
 use function array_filter;
 use function array_merge;
 use function array_values;
 use function count;
 use function in_array;
 use function sprintf;
 use function strlen;
-use function substr;
 
 /**
  * @implements Rule<Node\Expr\FuncCall>
  */
 class RegularExpressionQuotingRule implements Rule
 {
 
-	public function __construct(private ReflectionProvider $reflectionProvider)
+	public function __construct(
+		private ReflectionProvider $reflectionProvider,
+		private RegexExpressionHelper $regexExpressionHelper,
+	)
 	{
 	}
 
@@ -76,7 +78,7 @@ public function processNode(Node $node, Scope $scope): array
 			return [];
 		}
 
-		$patternDelimiters = $this->getDelimitersFromConcat($normalizedArgs[0]->value, $scope);
+		$patternDelimiters = $this->regexExpressionHelper->getPatternDelimiters($normalizedArgs[0]->value, $scope);
 		return $this->validateQuoteDelimiters($normalizedArgs[0]->value, $scope, $patternDelimiters);
 	}
 
@@ -193,40 +195,6 @@ private function validatePregQuote(FuncCall $pregQuote, Scope $scope, array $pat
 		return null;
 	}
 
-	/**
-	 * Get delimiters from non-constant patterns, if possible.
-	 *
-	 * @return string[]
-	 */
-	private function getDelimitersFromConcat(Concat $concat, Scope $scope): array
-	{
-		if ($concat->left instanceof Concat) {
-			return $this->getDelimitersFromConcat($concat->left, $scope);
-		}
-
-		$left = $scope->getType($concat->left);
-
-		$delimiters = [];
-		foreach ($left->getConstantStrings() as $leftString) {
-			$delimiter = $this->getDelimiterFromString($leftString);
-			if ($delimiter === null) {
-				continue;
-			}
-
-			$delimiters[] = $delimiter;
-		}
-		return $delimiters;
-	}
-
-	private function getDelimiterFromString(ConstantStringType $string): ?string
-	{
-		if ($string->getValue() === '') {
-			return null;
-		}
-
-		return substr($string->getValue(), 0, 1);
-	}
-
 	/**
 	 * @param string[] $delimiters
 	 *

src/Type/Php/RegexExpressionHelper.php

@@ -3,12 +3,14 @@
 namespace PHPStan\Type\Php;
 
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\BinaryOp\Concat;
 use PhpParser\Node\Name;
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\InitializerExprTypeResolver;
 use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeCombinator;
+use function substr;
 
 final class RegexExpressionHelper
 {
@@ -26,7 +28,7 @@ public function __construct(
 	 *
 	 * see https://github.com/phpstan/phpstan-src/pull/3233#discussion_r1676938085
 	 */
-	public function resolvePatternConcat(Expr\BinaryOp\Concat $concat, Scope $scope): Type
+	public function resolvePatternConcat(Concat $concat, Scope $scope): Type
 	{
 		$resolver = new class($scope) {
 
@@ -44,7 +46,7 @@ public function resolve(Expr $expr): Type
 					return new ConstantStringType('');
 				}
 
-				if ($expr instanceof Expr\BinaryOp\Concat) {
+				if ($expr instanceof Concat) {
 					$left = $this->resolve($expr->left);
 					$right = $this->resolve($expr->right);
 
@@ -66,4 +68,38 @@ public function resolve(Expr $expr): Type
 		return $this->initializerExprTypeResolver->getConcatType($concat->left, $concat->right, static fn (Expr $expr): Type => $resolver->resolve($expr));
 	}
 
+	/**
+	 * Get delimiters from non-constant patterns, if possible.
+	 *
+	 * @return string[]
+	 */
+	public function getPatternDelimiters(Concat $concat, Scope $scope): array
+	{
+		if ($concat->left instanceof Concat) {
+			return $this->getPatternDelimiters($concat->left, $scope);
+		}
+
+		$left = $scope->getType($concat->left);
+
+		$delimiters = [];
+		foreach ($left->getConstantStrings() as $leftString) {
+			$delimiter = $this->getDelimiterFromString($leftString);
+			if ($delimiter === null) {
+				continue;
+			}
+
+			$delimiters[] = $delimiter;
+		}
+		return $delimiters;
+	}
+
+	private function getDelimiterFromString(ConstantStringType $string): ?string
+	{
+		if ($string->getValue() === '') {
+			return null;
+		}
+
+		return substr($string->getValue(), 0, 1);
+	}
+
 }

tests/PHPStan/Rules/Regexp/RegularExpressionQuotingRuleTest.php

@@ -4,6 +4,7 @@
 
 use PHPStan\Rules\Rule;
 use PHPStan\Testing\RuleTestCase;
+use PHPStan\Type\Php\RegexExpressionHelper;
 use const PHP_VERSION_ID;
 
 /**
@@ -14,7 +15,10 @@ class RegularExpressionQuotingRuleTest extends RuleTestCase
 
 	protected function getRule(): Rule
 	{
-		return new RegularExpressionQuotingRule($this->createReflectionProvider());
+		return new RegularExpressionQuotingRule(
+			$this->createReflectionProvider(),
+			self::getContainer()->getByType(RegexExpressionHelper::class),
+		);
 	}
 
 	public function testRule(): void