From e49edb31bbf52c1fd8923301d5c8b0f33a2a9673 Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 15:52:25 +0200
Subject: [PATCH 01/12] Fix "Differing behaviors when requiring or including
 relatively vs using __DIR__"

---
 src/Rules/Keywords/RequireFileExistsRule.php  | 22 ++++++++++++++++---
 .../Keywords/RequireFileExistsRuleTest.php    |  6 ++++-
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/src/Rules/Keywords/RequireFileExistsRule.php b/src/Rules/Keywords/RequireFileExistsRule.php
index b0d4def3093..cfd76c79494 100644
--- a/src/Rules/Keywords/RequireFileExistsRule.php
+++ b/src/Rules/Keywords/RequireFileExistsRule.php
@@ -3,11 +3,13 @@
 namespace PHPStan\Rules\Keywords;
 
 use PhpParser\Node;
+use PhpParser\Node\Expr;
 use PhpParser\Node\Expr\Include_;
 use PHPStan\Analyser\Scope;
 use PHPStan\DependencyInjection\AutowiredParameter;
 use PHPStan\DependencyInjection\RegisteredRule;
 use PHPStan\File\FileHelper;
+use PHPStan\Node\Printer\ExprPrinter;
 use PHPStan\Rules\IdentifierRuleError;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
@@ -30,6 +32,7 @@ final class RequireFileExistsRule implements Rule
 	public function __construct(
 		#[AutowiredParameter]
 		private string $currentWorkingDirectory,
+		private ExprPrinter $exprPrinter,
 	)
 	{
 	}
@@ -49,7 +52,7 @@ public function processNode(Node $node, Scope $scope): array
 				continue;
 			}
 
-			$errors[] = $this->getErrorMessage($node, $path);
+			$errors[] = $this->getErrorMessage($node, $this->exprPrinter->printExpr($node->expr));
 		}
 
 		return $errors;
@@ -90,7 +93,7 @@ private function doesFileExistForDirectory(string $path, string $workingDirector
 
 	private function getErrorMessage(Include_ $node, string $filePath): IdentifierRuleError
 	{
-		$message = 'Path in %s() "%s" is not a file or it does not exist.';
+		$message = 'Path in %s() %s is not a file or it does not exist.';
 
 		switch ($node->type) {
 			case Include_::TYPE_REQUIRE:
@@ -130,7 +133,7 @@ private function getErrorMessage(Include_ $node, string $filePath): IdentifierRu
 	private function resolveFilePaths(Include_ $node, Scope $scope): array
 	{
 		$paths = [];
-		$type = $scope->getType($node->expr);
+		$type = $scope->getType($this->resolveMagicPaths($node->expr, $scope));
 		$constantStrings = $type->getConstantStrings();
 
 		foreach ($constantStrings as $constantString) {
@@ -140,4 +143,17 @@ private function resolveFilePaths(Include_ $node, Scope $scope): array
 		return $paths;
 	}
 
+	private function resolveMagicPaths(Expr $expr, Scope $scope): Expr
+	{
+		if (!$expr instanceof Expr\BinaryOp\Concat) {
+			return $expr;
+		}
+
+		if ($expr->left instanceof Node\Scalar\MagicConst\Dir && $expr->right instanceof Node\Scalar\String_) {
+			return new Node\Scalar\String_(dirname($scope->getFile()). $expr->right->value);
+		}
+
+		return $expr;
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
index 732819b506c..1527b6598ff 100644
--- a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
+++ b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
@@ -2,6 +2,7 @@
 
 namespace PHPStan\Rules\Keywords;
 
+use PHPStan\Node\Printer\ExprPrinter;
 use PHPStan\Rules\Rule;
 use PHPStan\Testing\RuleTestCase;
 use function get_include_path;
@@ -21,7 +22,10 @@ class RequireFileExistsRuleTest extends RuleTestCase
 
 	protected function getRule(): Rule
 	{
-		return new RequireFileExistsRule($this->currentWorkingDirectory);
+		return new RequireFileExistsRule(
+			$this->currentWorkingDirectory,
+			self::getContainer()->getByType(ExprPrinter::class)
+		);
 	}
 
 	public static function getAdditionalConfigFiles(): array

From 3b43a97f8f772a0dfb51c8dc00330d0bf99452cd Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 16:06:12 +0200
Subject: [PATCH 02/12] Update RequireFileExistsRule.php

---
 src/Rules/Keywords/RequireFileExistsRule.php | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/Rules/Keywords/RequireFileExistsRule.php b/src/Rules/Keywords/RequireFileExistsRule.php
index cfd76c79494..ae314a8dd84 100644
--- a/src/Rules/Keywords/RequireFileExistsRule.php
+++ b/src/Rules/Keywords/RequireFileExistsRule.php
@@ -52,7 +52,12 @@ public function processNode(Node $node, Scope $scope): array
 				continue;
 			}
 
-			$errors[] = $this->getErrorMessage($node, $this->exprPrinter->printExpr($node->expr));
+			$pathExpr = $this->exprPrinter->printExpr($node->expr);
+			if (!str_contains('"', $pathExpr)) {
+				$pathExpr = '"' . trim($path, "'") . '"';
+			}
+
+			$errors[] = $this->getErrorMessage($node, $pathExpr);
 		}
 
 		return $errors;

From 0c3c91ce5b2531996c06cac3fd95c661b015aed2 Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 16:07:48 +0200
Subject: [PATCH 03/12] Create RequireFileExistsRuleNoConstantPathTest.php

---
 ...equireFileExistsRuleNoConstantPathTest.php | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php

diff --git a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php
new file mode 100644
index 00000000000..ecb65f04ddd
--- /dev/null
+++ b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php
@@ -0,0 +1,45 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Keywords;
+
+use PHPStan\Node\Printer\ExprPrinter;
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+use function get_include_path;
+use function implode;
+use function realpath;
+use function set_include_path;
+use const DIRECTORY_SEPARATOR;
+use const PATH_SEPARATOR;
+
+/**
+ * @extends RuleTestCase<RequireFileExistsRule>
+ */
+class RequireFileExistsRuleNoConstantPathTest extends RuleTestCase
+{
+
+	private string $currentWorkingDirectory = __DIR__ . '/../';
+
+	protected function getRule(): Rule
+	{
+		return new RequireFileExistsRule(
+			$this->currentWorkingDirectory,
+			self::getContainer()->getByType(ExprPrinter::class)
+		);
+	}
+
+	public function testBug12203NoConstantPath(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-12203.php'], [
+			[
+				'Path in require_once() "../bug-12203-sure-does-not-exist.php" is not a file or it does not exist.',
+				5,
+			],
+			[
+				'Path in require_once() "' . __DIR__ . DIRECTORY_SEPARATOR . 'data/../bug-12203-sure-does-not-exist.php" is not a file or it does not exist.',
+				6,
+			],
+		]);
+	}
+
+}

From 981b7d23acb49d6b5582bae5064939bfbf099af1 Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 16:11:55 +0200
Subject: [PATCH 04/12] Update RequireFileExistsRule.php

---
 src/Rules/Keywords/RequireFileExistsRule.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/Rules/Keywords/RequireFileExistsRule.php b/src/Rules/Keywords/RequireFileExistsRule.php
index ae314a8dd84..7dd9c880ad9 100644
--- a/src/Rules/Keywords/RequireFileExistsRule.php
+++ b/src/Rules/Keywords/RequireFileExistsRule.php
@@ -20,6 +20,8 @@
 use function get_include_path;
 use function is_file;
 use function sprintf;
+use function str_contains;
+use function trim;
 use const PATH_SEPARATOR;
 
 /**
@@ -155,7 +157,7 @@ private function resolveMagicPaths(Expr $expr, Scope $scope): Expr
 		}
 
 		if ($expr->left instanceof Node\Scalar\MagicConst\Dir && $expr->right instanceof Node\Scalar\String_) {
-			return new Node\Scalar\String_(dirname($scope->getFile()). $expr->right->value);
+			return new Node\Scalar\String_(dirname($scope->getFile()) . $expr->right->value);
 		}
 
 		return $expr;

From 489a70054980fe75fb3eb3374dba82b727927351 Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 16:12:25 +0200
Subject: [PATCH 05/12] cs

---
 .../Keywords/RequireFileExistsRuleNoConstantPathTest.php   | 7 +------
 tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php | 2 +-
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php
index ecb65f04ddd..d6534763687 100644
--- a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php
+++ b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php
@@ -5,12 +5,7 @@
 use PHPStan\Node\Printer\ExprPrinter;
 use PHPStan\Rules\Rule;
 use PHPStan\Testing\RuleTestCase;
-use function get_include_path;
-use function implode;
-use function realpath;
-use function set_include_path;
 use const DIRECTORY_SEPARATOR;
-use const PATH_SEPARATOR;
 
 /**
  * @extends RuleTestCase<RequireFileExistsRule>
@@ -24,7 +19,7 @@ protected function getRule(): Rule
 	{
 		return new RequireFileExistsRule(
 			$this->currentWorkingDirectory,
-			self::getContainer()->getByType(ExprPrinter::class)
+			self::getContainer()->getByType(ExprPrinter::class),
 		);
 	}
 
diff --git a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
index 1527b6598ff..42f23734f74 100644
--- a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
+++ b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
@@ -24,7 +24,7 @@ protected function getRule(): Rule
 	{
 		return new RequireFileExistsRule(
 			$this->currentWorkingDirectory,
-			self::getContainer()->getByType(ExprPrinter::class)
+			self::getContainer()->getByType(ExprPrinter::class),
 		);
 	}
 

From 5d19ffd1c2e491b1ef2d32c30075f9b75340a595 Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 16:31:47 +0200
Subject: [PATCH 06/12] skip lines within file_exists()/is_file()

---
 src/Rules/Keywords/RequireFileExistsRule.php  | 22 +++++++++++++++++++
 ...equireFileExistsRuleNoConstantPathTest.php |  5 +++++
 .../Keywords/RequireFileExistsRuleTest.php    |  5 +++++
 .../Keywords/data/include-in-file-exists.php  |  9 ++++++++
 4 files changed, 41 insertions(+)
 create mode 100644 tests/PHPStan/Rules/Keywords/data/include-in-file-exists.php

diff --git a/src/Rules/Keywords/RequireFileExistsRule.php b/src/Rules/Keywords/RequireFileExistsRule.php
index 7dd9c880ad9..fefd9255baa 100644
--- a/src/Rules/Keywords/RequireFileExistsRule.php
+++ b/src/Rules/Keywords/RequireFileExistsRule.php
@@ -3,8 +3,11 @@
 namespace PHPStan\Rules\Keywords;
 
 use PhpParser\Node;
+use PhpParser\Node\Arg;
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\FuncCall;
 use PhpParser\Node\Expr\Include_;
+use PhpParser\Node\Name\FullyQualified;
 use PHPStan\Analyser\Scope;
 use PHPStan\DependencyInjection\AutowiredParameter;
 use PHPStan\DependencyInjection\RegisteredRule;
@@ -49,6 +52,10 @@ public function processNode(Node $node, Scope $scope): array
 		$errors = [];
 		$paths = $this->resolveFilePaths($node, $scope);
 
+		if ($this->isInFileExists($node, $scope)) {
+			return [];
+		}
+
 		foreach ($paths as $path) {
 			if ($this->doesFileExist($path, $scope)) {
 				continue;
@@ -163,4 +170,19 @@ private function resolveMagicPaths(Expr $expr, Scope $scope): Expr
 		return $expr;
 	}
 
+	private function isInFileExists(Include_|Node $node, Scope $scope)
+	{
+		foreach (['file_exists', 'is_file'] as $funcName) {
+			$expr = new FuncCall(new FullyQualified($funcName), [
+				new Arg($node->expr),
+			]);
+
+			if ($scope->getType($expr)->isTrue()->yes()) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php
index d6534763687..c6cc169760c 100644
--- a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php
+++ b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php
@@ -37,4 +37,9 @@ public function testBug12203NoConstantPath(): void
 		]);
 	}
 
+	public function testInFileExists(): void
+	{
+		$this->analyse([__DIR__ . '/data/include-in-file-exists.php'], []);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
index 42f23734f74..df58cbfd654 100644
--- a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
+++ b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
@@ -140,4 +140,9 @@ public function testBug12203(): void
 		]);
 	}
 
+	public function testInFileExists(): void
+	{
+		$this->analyse([__DIR__ . '/data/include-in-file-exists.php'], []);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Keywords/data/include-in-file-exists.php b/tests/PHPStan/Rules/Keywords/data/include-in-file-exists.php
new file mode 100644
index 00000000000..74e271d3309
--- /dev/null
+++ b/tests/PHPStan/Rules/Keywords/data/include-in-file-exists.php
@@ -0,0 +1,9 @@
+<?php
+
+if (file_exists(__DIR__ . '/../vendor/autoload.php')) {
+	require __DIR__ . '/../vendor/autoload.php';
+}
+
+if (is_file(__DIR__ . '/../vendor/autoload.php')) {
+	require __DIR__ . '/../vendor/autoload.php';
+}

From 25b11fa544313be9df85dadba3f5ee53ed62a853 Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 16:35:53 +0200
Subject: [PATCH 07/12] Update RequireFileExistsRule.php

---
 src/Rules/Keywords/RequireFileExistsRule.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Rules/Keywords/RequireFileExistsRule.php b/src/Rules/Keywords/RequireFileExistsRule.php
index fefd9255baa..06a70d530fd 100644
--- a/src/Rules/Keywords/RequireFileExistsRule.php
+++ b/src/Rules/Keywords/RequireFileExistsRule.php
@@ -170,7 +170,7 @@ private function resolveMagicPaths(Expr $expr, Scope $scope): Expr
 		return $expr;
 	}
 
-	private function isInFileExists(Include_|Node $node, Scope $scope)
+	private function isInFileExists(Include_ $node, Scope $scope): bool
 	{
 		foreach (['file_exists', 'is_file'] as $funcName) {
 			$expr = new FuncCall(new FullyQualified($funcName), [

From aef31618e7940d35297d5ae72c89119f15f5e038 Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 16:45:34 +0200
Subject: [PATCH 08/12] Update RequireFileExistsRule.php

---
 src/Rules/Keywords/RequireFileExistsRule.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Rules/Keywords/RequireFileExistsRule.php b/src/Rules/Keywords/RequireFileExistsRule.php
index 06a70d530fd..a9a14540408 100644
--- a/src/Rules/Keywords/RequireFileExistsRule.php
+++ b/src/Rules/Keywords/RequireFileExistsRule.php
@@ -164,7 +164,7 @@ private function resolveMagicPaths(Expr $expr, Scope $scope): Expr
 		}
 
 		if ($expr->left instanceof Node\Scalar\MagicConst\Dir && $expr->right instanceof Node\Scalar\String_) {
-			return new Node\Scalar\String_(dirname($scope->getFile()) . $expr->right->value);
+			return new Node\Scalar\String_(dirname($scope->getFile()) .'/'. $expr->right->value);
 		}
 
 		return $expr;

From 1d5e64d79bf64aa0010e9c6ccef7504633128e2b Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 16:47:59 +0200
Subject: [PATCH 09/12] Revert "Update RequireFileExistsRule.php"

This reverts commit aef31618e7940d35297d5ae72c89119f15f5e038.
---
 src/Rules/Keywords/RequireFileExistsRule.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Rules/Keywords/RequireFileExistsRule.php b/src/Rules/Keywords/RequireFileExistsRule.php
index a9a14540408..06a70d530fd 100644
--- a/src/Rules/Keywords/RequireFileExistsRule.php
+++ b/src/Rules/Keywords/RequireFileExistsRule.php
@@ -164,7 +164,7 @@ private function resolveMagicPaths(Expr $expr, Scope $scope): Expr
 		}
 
 		if ($expr->left instanceof Node\Scalar\MagicConst\Dir && $expr->right instanceof Node\Scalar\String_) {
-			return new Node\Scalar\String_(dirname($scope->getFile()) .'/'. $expr->right->value);
+			return new Node\Scalar\String_(dirname($scope->getFile()) . $expr->right->value);
 		}
 
 		return $expr;

From 0fa6512a45bfcefcd5838546f4e8ac6aa39c06d5 Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 21:11:33 +0200
Subject: [PATCH 10/12] Update RequireFileExistsRule.php

---
 src/Rules/Keywords/RequireFileExistsRule.php | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/Rules/Keywords/RequireFileExistsRule.php b/src/Rules/Keywords/RequireFileExistsRule.php
index 06a70d530fd..6c1e8ee2072 100644
--- a/src/Rules/Keywords/RequireFileExistsRule.php
+++ b/src/Rules/Keywords/RequireFileExistsRule.php
@@ -49,20 +49,20 @@ public function getNodeType(): string
 
 	public function processNode(Node $node, Scope $scope): array
 	{
-		$errors = [];
-		$paths = $this->resolveFilePaths($node, $scope);
-
 		if ($this->isInFileExists($node, $scope)) {
 			return [];
 		}
 
+		$errors = [];
+		$paths = $this->resolveFilePaths($node, $scope);
+
 		foreach ($paths as $path) {
 			if ($this->doesFileExist($path, $scope)) {
 				continue;
 			}
 
 			$pathExpr = $this->exprPrinter->printExpr($node->expr);
-			if (!str_contains('"', $pathExpr)) {
+			if (!str_contains($pathExpr, '"')) {
 				$pathExpr = '"' . trim($path, "'") . '"';
 			}
 

From b5cc8ad9b828a52f5b3e088711d4718752b4c67e Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 21:18:18 +0200
Subject: [PATCH 11/12] refactor

---
 src/Rules/Keywords/RequireFileExistsRule.php | 30 +++++++++-----------
 1 file changed, 13 insertions(+), 17 deletions(-)

diff --git a/src/Rules/Keywords/RequireFileExistsRule.php b/src/Rules/Keywords/RequireFileExistsRule.php
index 6c1e8ee2072..84b8354bbcb 100644
--- a/src/Rules/Keywords/RequireFileExistsRule.php
+++ b/src/Rules/Keywords/RequireFileExistsRule.php
@@ -17,6 +17,7 @@
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
 use PHPStan\ShouldNotHappenException;
+use PHPStan\Type\Constant\ConstantStringType;
 use function array_merge;
 use function dirname;
 use function explode;
@@ -57,6 +58,8 @@ public function processNode(Node $node, Scope $scope): array
 		$paths = $this->resolveFilePaths($node, $scope);
 
 		foreach ($paths as $path) {
+			$path = $path->getValue();
+
 			if ($this->doesFileExist($path, $scope)) {
 				continue;
 			}
@@ -142,32 +145,25 @@ private function getErrorMessage(Include_ $node, string $filePath): IdentifierRu
 	}
 
 	/**
-	 * @return array<string>
+	 * @return array<ConstantStringType>
 	 */
 	private function resolveFilePaths(Include_ $node, Scope $scope): array
 	{
-		$paths = [];
-		$type = $scope->getType($this->resolveMagicPaths($node->expr, $scope));
-		$constantStrings = $type->getConstantStrings();
-
-		foreach ($constantStrings as $constantString) {
-			$paths[] = $constantString->getValue();
-		}
+		$expr = $node->expr;
 
-		return $paths;
-	}
-
-	private function resolveMagicPaths(Expr $expr, Scope $scope): Expr
-	{
 		if (!$expr instanceof Expr\BinaryOp\Concat) {
-			return $expr;
+			return $scope->getType($expr)->getConstantStrings();
 		}
 
-		if ($expr->left instanceof Node\Scalar\MagicConst\Dir && $expr->right instanceof Node\Scalar\String_) {
-			return new Node\Scalar\String_(dirname($scope->getFile()) . $expr->right->value);
+		if ($expr->left instanceof Node\Scalar\MagicConst\Dir) {
+			$paths = [];
+			foreach ($scope->getType($expr->right)->getConstantStrings() as $constantString) {
+				$paths[] = new ConstantStringType(dirname($scope->getFile()) . $constantString->getValue());
+			}
+			return $paths;
 		}
 
-		return $expr;
+		return $scope->getType($expr)->getConstantStrings();
 	}
 
 	private function isInFileExists(Include_ $node, Scope $scope): bool

From d8a9e5227171f8b0045745020edb041cf9fcd461 Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sat, 13 Jun 2026 21:44:23 +0200
Subject: [PATCH 12/12] improve error message

---
 src/Rules/Keywords/RequireFileExistsRule.php  | 19 +++++++++++--------
 ...equireFileExistsRuleNoConstantPathTest.php |  3 +--
 .../Keywords/RequireFileExistsRuleTest.php    |  3 +--
 3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/src/Rules/Keywords/RequireFileExistsRule.php b/src/Rules/Keywords/RequireFileExistsRule.php
index 84b8354bbcb..0a3e6e35a5b 100644
--- a/src/Rules/Keywords/RequireFileExistsRule.php
+++ b/src/Rules/Keywords/RequireFileExistsRule.php
@@ -24,8 +24,6 @@
 use function get_include_path;
 use function is_file;
 use function sprintf;
-use function str_contains;
-use function trim;
 use const PATH_SEPARATOR;
 
 /**
@@ -55,7 +53,8 @@ public function processNode(Node $node, Scope $scope): array
 		}
 
 		$errors = [];
-		$paths = $this->resolveFilePaths($node, $scope);
+		$usedMagicDirFallback = false;
+		$paths = $this->resolveFilePaths($node, $scope, $usedMagicDirFallback);
 
 		foreach ($paths as $path) {
 			$path = $path->getValue();
@@ -64,9 +63,10 @@ public function processNode(Node $node, Scope $scope): array
 				continue;
 			}
 
-			$pathExpr = $this->exprPrinter->printExpr($node->expr);
-			if (!str_contains($pathExpr, '"')) {
-				$pathExpr = '"' . trim($path, "'") . '"';
+			if ($usedMagicDirFallback) {
+				$pathExpr = $this->exprPrinter->printExpr($node->expr);
+			} else {
+				$pathExpr = '"' . $path . '"';
 			}
 
 			$errors[] = $this->getErrorMessage($node, $pathExpr);
@@ -145,10 +145,11 @@ private function getErrorMessage(Include_ $node, string $filePath): IdentifierRu
 	}
 
 	/**
-	 * @return array<ConstantStringType>
+	 * @return list<ConstantStringType>
 	 */
-	private function resolveFilePaths(Include_ $node, Scope $scope): array
+	private function resolveFilePaths(Include_ $node, Scope $scope, bool &$magicDirFallback): array
 	{
+		$magicDirFallback = false;
 		$expr = $node->expr;
 
 		if (!$expr instanceof Expr\BinaryOp\Concat) {
@@ -156,6 +157,8 @@ private function resolveFilePaths(Include_ $node, Scope $scope): array
 		}
 
 		if ($expr->left instanceof Node\Scalar\MagicConst\Dir) {
+			$magicDirFallback = true;
+
 			$paths = [];
 			foreach ($scope->getType($expr->right)->getConstantStrings() as $constantString) {
 				$paths[] = new ConstantStringType(dirname($scope->getFile()) . $constantString->getValue());
diff --git a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php
index c6cc169760c..b967cdbe56d 100644
--- a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php
+++ b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleNoConstantPathTest.php
@@ -5,7 +5,6 @@
 use PHPStan\Node\Printer\ExprPrinter;
 use PHPStan\Rules\Rule;
 use PHPStan\Testing\RuleTestCase;
-use const DIRECTORY_SEPARATOR;
 
 /**
  * @extends RuleTestCase<RequireFileExistsRule>
@@ -31,7 +30,7 @@ public function testBug12203NoConstantPath(): void
 				5,
 			],
 			[
-				'Path in require_once() "' . __DIR__ . DIRECTORY_SEPARATOR . 'data/../bug-12203-sure-does-not-exist.php" is not a file or it does not exist.',
+				"Path in require_once() __DIR__ . '/../bug-12203-sure-does-not-exist.php' is not a file or it does not exist.",
 				6,
 			],
 		]);
diff --git a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
index df58cbfd654..ee7835c51a7 100644
--- a/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
+++ b/tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php
@@ -9,7 +9,6 @@
 use function implode;
 use function realpath;
 use function set_include_path;
-use const DIRECTORY_SEPARATOR;
 use const PATH_SEPARATOR;
 
 /**
@@ -134,7 +133,7 @@ public function testBug12203(): void
 				5,
 			],
 			[
-				'Path in require_once() "' . __DIR__ . DIRECTORY_SEPARATOR . 'data/../bug-12203-sure-does-not-exist.php" is not a file or it does not exist.',
+				"Path in require_once() __DIR__ . '/../bug-12203-sure-does-not-exist.php' is not a file or it does not exist.",
 				6,
 			],
 		]);