RegexArrayShapeMatcher - Support preg_quote()'d patterns

Author: staabm

src/Type/Php/PregMatchParameterOutTypeExtension.php

@@ -41,13 +41,12 @@ public function getParameterOutTypeFromFunctionCall(FunctionReflection $function
 			return null;
 		}
 
-		$patternType = $scope->getType($patternArg->value);
 		$flagsType = null;
 		if ($flagsArg !== null) {
 			$flagsType = $scope->getType($flagsArg->value);
 		}
 
-		return $this->regexShapeMatcher->matchType($patternType, $flagsType, TrinaryLogic::createMaybe());
+		return $this->regexShapeMatcher->matchExpr($patternArg->value, $flagsType, TrinaryLogic::createMaybe(), $scope);
 	}
 
 }

src/Type/Php/PregMatchTypeSpecifyingExtension.php

@@ -48,13 +48,12 @@ public function specifyTypes(FunctionReflection $functionReflection, FuncCall $n
 			return new SpecifiedTypes();
 		}
 
-		$patternType = $scope->getType($patternArg->value);
 		$flagsType = null;
 		if ($flagsArg !== null) {
 			$flagsType = $scope->getType($flagsArg->value);
 		}
 
-		$matchedType = $this->regexShapeMatcher->matchType($patternType, $flagsType, TrinaryLogic::createFromBoolean($context->true()));
+		$matchedType = $this->regexShapeMatcher->matchExpr($patternArg->value, $flagsType, TrinaryLogic::createFromBoolean($context->true()), $scope);
 		if ($matchedType === null) {
 			return new SpecifiedTypes();
 		}

src/Type/Php/RegexArrayShapeMatcher.php

@@ -7,6 +7,9 @@
 use Hoa\Compiler\Llk\TreeNode;
 use Hoa\Exception\Exception;
 use Hoa\File\Read;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Name;
+use PHPStan\Analyser\Scope;
 use PHPStan\Php\PhpVersion;
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\Constant\ConstantArrayType;
@@ -45,7 +48,20 @@ public function __construct(
 	{
 	}
 
+	public function matchExpr(Expr $patternExpr, ?Type $flagsType, TrinaryLogic $wasMatched, Scope $scope): ?Type
+	{
+		return $this->matchPatternType($this->getPatternType($patternExpr, $scope), $flagsType, $wasMatched);
+	}
+
+	/**
+	 * @deprecated use matchExpr() instead for a more precise result
+	 */
 	public function matchType(Type $patternType, ?Type $flagsType, TrinaryLogic $wasMatched): ?Type
+	{
+		return $this->matchPatternType($patternType, $flagsType, $wasMatched);
+	}
+
+	private function matchPatternType(Type $patternType, ?Type $flagsType, TrinaryLogic $wasMatched): ?Type
 	{
 		if ($wasMatched->no()) {
 			return new ConstantArrayType([], []);
@@ -484,4 +500,56 @@ private function walkRegexAst(
 		}
 	}
 
+	private function getPatternType(Expr $patternExpr, Scope $scope): Type
+	{
+		if ($patternExpr instanceof Expr\BinaryOp\Concat) {
+			return $this->resolvePatternConcat($patternExpr, $scope);
+		}
+
+		return $scope->getType($patternExpr);
+	}
+
+	/**
+	 * Ignores preg_quote() calls in the concatenation as these are not relevant for array-shape matching.
+	 *
+	 * This assumption only works for the ArrayShapeMatcher therefore it is not implemented for the common case in Scope.
+	 *
+	 * see https://github.com/phpstan/phpstan-src/pull/3233#discussion_r1676938085
+	 */
+	private function resolvePatternConcat(Expr\BinaryOp\Concat $concat, Scope $scope): Type
+	{
+		if (
+			$concat->left instanceof Expr\FuncCall
+			&& $concat->left->name instanceof Name
+			&& $concat->left->name->toLowerString() === 'preg_quote'
+		) {
+			$left = new ConstantStringType('');
+		} elseif ($concat->left instanceof Expr\BinaryOp\Concat) {
+			$left = $this->resolvePatternConcat($concat->left, $scope);
+		} else {
+			$left = $scope->getType($concat->left);
+		}
+
+		if (
+			$concat->right instanceof Expr\FuncCall
+			&& $concat->right->name instanceof Name
+			&& $concat->right->name->toLowerString() === 'preg_quote'
+		) {
+			$right = new ConstantStringType('');
+		} elseif ($concat->right instanceof Expr\BinaryOp\Concat) {
+			$right = $this->resolvePatternConcat($concat->right, $scope);
+		} else {
+			$right = $scope->getType($concat->right);
+		}
+
+		$strings = [];
+		foreach ($left->getConstantStrings() as $leftString) {
+			foreach ($right->getConstantStrings() as $rightString) {
+				$strings[] = new ConstantStringType($leftString->getValue() . $rightString->getValue());
+			}
+		}
+
+		return TypeCombinator::union(...$strings);
+	}
+
 }

tests/PHPStan/Analyser/nsrt/preg_match_shapes.php

@@ -393,3 +393,47 @@ function unmatchedAsNullWithMandatoryGroup(string $s): void {
 	assertType('array{}|array{0: string, currency: string, 1: string}', $matches);
 }
 
+function (string $s): void {
+	if (preg_match('{' . preg_quote('xxx') . '(z)}', $s, $matches)) {
+		assertType('array{string, string}', $matches);
+	} else {
+		assertType('array{}', $matches);
+	}
+	assertType('array{}|array{string, string}', $matches);
+};
+
+function (string $s): void {
+	if (preg_match('{' . preg_quote($s) . '(z)}', $s, $matches)) {
+		assertType('array{string, string}', $matches);
+	} else {
+		assertType('array{}', $matches);
+	}
+	assertType('array{}|array{string, string}', $matches);
+};
+
+function (string $s): void {
+	if (preg_match('/' . preg_quote($s, '/') . '(\d)/', $s, $matches)) {
+		assertType('array{string, string}', $matches);
+	} else {
+		assertType('array{}', $matches);
+	}
+	assertType('array{}|array{string, string}', $matches);
+};
+
+function (string $s): void {
+	if (preg_match('{' . preg_quote($s) . '(z)' . preg_quote($s) . '(?:abc)(def)?}', $s, $matches)) {
+		assertType('array{0: string, 1: string, 2?: string}', $matches);
+	} else {
+		assertType('array{}', $matches);
+	}
+	assertType('array{}|array{0: string, 1: string, 2?: string}', $matches);
+};
+
+function (string $s, $mixed): void {
+	if (preg_match('{' . preg_quote($s) . '(z)' . preg_quote($s) . '(?:abc)'. $mixed .'(def)?}', $s, $matches)) {
+		assertType('array<string>', $matches);
+	} else {
+		assertType('array{}', $matches);
+	}
+	assertType('array<string>', $matches);
+};