diff --git a/lib/private/fileproxy.php b/lib/private/fileproxy.php
index 52ec79b4bd..2997aaf81b 100644
--- a/lib/private/fileproxy.php
+++ b/lib/private/fileproxy.php
@@ -67,7 +67,11 @@ class OC_FileProxy{
 		self::$proxies[]=$proxy;
 	}
 
-	public static function getProxies($operation) {
+	public static function getProxies($operation = null) {
+		if ($operation === null) {
+			// return all
+			return self::$proxies;
+		}
 		$proxies=array();
 		foreach(self::$proxies as $proxy) {
 			if(method_exists($proxy, $operation)) {
diff --git a/lib/private/hook.php b/lib/private/hook.php
index 8516cf0dcf..b63b442c31 100644
--- a/lib/private/hook.php
+++ b/lib/private/hook.php
@@ -97,4 +97,12 @@ class OC_Hook{
 			self::$registered=array();
 		}
 	}
+
+	/**
+	 * DO NOT USE!
+	 * For unit tests ONLY!
+	 */
+	static public function getHooks() {
+		return self::$registered;
+	}
 }
diff --git a/tests/phpunit-autotest.xml b/tests/phpunit-autotest.xml
index a893e96ad9..1a2ab35491 100644
--- a/tests/phpunit-autotest.xml
+++ b/tests/phpunit-autotest.xml
@@ -35,5 +35,12 @@
 			</exclude>
 		</whitelist>
 	</filter>
+	<listeners>
+	  <listener class="TestCleanupListener" file="testcleanuplistener.php">
+		<arguments>
+			<string>detail</string>
+		</arguments>
+	  </listener>
+	</listeners>
 </phpunit>
 
diff --git a/tests/testcleanuplistener.php b/tests/testcleanuplistener.php
new file mode 100644
index 0000000000..368ea7bc8f
--- /dev/null
+++ b/tests/testcleanuplistener.php
@@ -0,0 +1,139 @@
+<?php
+/**
+ * Copyright (c) 2013 Vincent Petry <pvince81@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+/**
+ * Detects tests that didn't clean up properly, show a warning, then clean up after them.
+ */
+class TestCleanupListener implements PHPUnit_Framework_TestListener {
+	private $verbosity;
+
+	public function __construct($verbosity = 'verbose') {
+		$this->verbosity = $verbosity;
+	}
+
+    public function addError(PHPUnit_Framework_Test $test, Exception $e, $time) {
+    }
+
+    public function addFailure(PHPUnit_Framework_Test $test, PHPUnit_Framework_AssertionFailedError $e, $time) {
+    }
+
+    public function addIncompleteTest(PHPUnit_Framework_Test $test, Exception $e, $time) {
+    }
+
+    public function addSkippedTest(PHPUnit_Framework_Test $test, Exception $e, $time) {
+    }
+
+    public function startTest(PHPUnit_Framework_Test $test) {
+    }
+
+    public function endTest(PHPUnit_Framework_Test $test, $time) {
+    }
+
+    public function startTestSuite(PHPUnit_Framework_TestSuite $suite) {
+    }
+
+    public function endTestSuite(PHPUnit_Framework_TestSuite $suite) {
+		if ($this->cleanStrayDataFiles() && $this->isShowSuiteWarning()) {
+			printf("TestSuite '%s': Did not clean up data dir\n", $suite->getName());
+		}
+		if ($this->cleanStrayHooks() && $this->isShowSuiteWarning()) {
+			printf("TestSuite '%s': Did not clean up hooks\n", $suite->getName());
+		}
+		if ($this->cleanProxies() && $this->isShowSuiteWarning()) {
+			printf("TestSuite '%s': Did not clean up proxies\n", $suite->getName());
+		}
+    }
+
+	private function isShowSuiteWarning() {
+		return $this->verbosity === 'suite' || $this->verbosity === 'detail';
+	}
+
+	private function isShowDetail() {
+		return $this->verbosity === 'detail';
+	}
+
+	private function unlinkDir($dir) {
+		if ($dh = opendir($dir)) {
+			while (($file = readdir($dh)) !== false) {
+				if ($file === '..' || $file === '.') {
+					continue;
+				}
+				$path = $dir . '/' . $file;
+				if (is_dir($path)) {
+					$this->unlinkDir($path);
+				}
+				else {
+					unlink($path);
+				}
+			}
+			closedir($dh);
+		}
+		rmdir($dir);
+	}
+
+	private function cleanStrayDataFiles() {
+		$knownEntries = array(
+			'owncloud.log' => true,
+			'owncloud.db' => true,
+			'..' => true,
+			'.' => true
+		);
+		$datadir = \OC_Config::getValue('datadirectory', \OC::$SERVERROOT . '/data');
+		$entries = array();
+		if ($dh = opendir($datadir)) {
+			while (($file = readdir($dh)) !== false) {
+				if (!isset($knownEntries[$file])) {
+					$entries[] = $file;
+				}
+			}
+			closedir($dh);
+		}
+
+		if (count($entries) > 0) {
+			foreach ($entries as $entry) {
+				$this->unlinkDir($datadir . '/' . $entry);
+				if ($this->isShowDetail()) {
+					printf("Stray datadir entry: %s\n", $entry);
+				}
+			}
+			return true;
+		}
+
+		return false;
+	}
+
+	private function cleanStrayHooks() {
+		$hasHooks = false;
+		$hooks = OC_Hook::getHooks();
+		if (!$hooks || sizeof($hooks) === 0) {
+			return false;
+		}
+
+		foreach ($hooks as $signalClass => $signals) {
+			if (sizeof($signals)) {
+				foreach ($signals as $signalName => $handlers ) {
+					if (sizeof($handlers) > 0) {
+						$hasHooks = true;
+						OC_Hook::clear($signalClass, $signalName);
+						if ($this->isShowDetail()) {
+							printf("Stray hook: \"%s\" \"%s\"\n", $signalClass, $signalName);
+						}
+					}
+				}
+			}
+		}
+		return $hasHooks;
+	}
+
+	private function cleanProxies() {
+		$proxies = OC_FileProxy::getProxies();
+		OC_FileProxy::clearProxies();
+		return count($proxies) > 0;
+	}
+}
+?>