simplify detect

Author: staabm

src/DependencyInjection/ContainerFactory.php

@@ -48,6 +48,7 @@
 use function spl_object_id;
 use function sprintf;
 use function str_ends_with;
+use function strtoupper;
 use function substr;
 
 /**
@@ -191,7 +192,8 @@ public static function postInitializeContainer(Container $container): void
 		$container->getService('typeSpecifier');
 
 		BleedingEdgeToggle::setBleedingEdge($container->getParameter('featureToggles')['bleedingEdge']);
-		FilesystemHelper::checkIsCaseSensitive($container->getParameter('tmpDir'));
+		// filename intentional in wrong case
+		FilesystemHelper::setIsCaseSensitive(is_file(__DIR__ . '/' . strtoupper(__FILE__)));
 	}
 
 	public function getCurrentWorkingDirectory(): string

src/File/FilesystemHelper.php

@@ -2,38 +2,24 @@
 
 namespace PHPStan\File;
 
-use function file_get_contents;
-use function file_put_contents;
-use function strtoupper;
+use PHPStan\ShouldNotHappenException;
 
 final class FilesystemHelper
 {
 
-	private const SIGNATURE_CONTENT = 'PHPStan case-sensitivity check';
-
 	private static ?bool $isCaseSensitive = null;
 
 	public static function isCaseSensitive(): bool
 	{
+		if (self::$isCaseSensitive === null) {
+			throw new ShouldNotHappenException();
+		}
 		return self::$isCaseSensitive;
 	}
 
-	public static function checkIsCaseSensitive(string $tmpDir): void
+	public static function setIsCaseSensitive(bool $isCaseSensitive): void
 	{
-		if (self::$isCaseSensitive !== null) {
-			return;
-		}
-
-		$fileName = 'test-file-system-case-sensitivity.tmp';
-		@file_put_contents($tmpDir . '/' . $fileName, self::SIGNATURE_CONTENT);
-
-		if (@file_get_contents($tmpDir . '/' . strtoupper($fileName)) === self::SIGNATURE_CONTENT) {
-			self::$isCaseSensitive = false;
-
-			return;
-		}
-
-		self::$isCaseSensitive = true;
+		self::$isCaseSensitive = $isCaseSensitive;
 	}
 
 }