CacheExtension: throws exception when is unable to create directory or directory is not writable

Author: dg

src/Bridges/CacheDI/CacheExtension.php

@@ -29,7 +29,14 @@ public function __construct($tempDir)
 
 	public function loadConfiguration()
 	{
-		@mkdir($this->tempDir . '/cache'); // @ - directory may exists
+		$dir = $this->tempDir . '/cache';
+		Nette\Utils\FileSystem::createDir($dir);
+
+		$uniq = uniqid('_', true);
+		if (!@mkdir("$dir/$uniq")) { // @ - is escalated to exception
+			throw new Nette\InvalidStateException("Unable to write to directory '$dir'. Make this directory writable.");
+		}
+		rmdir("$dir/$uniq");
 
 		$builder = $this->getContainerBuilder();