Merge pull request #48219 from nextcloud/fix/istorage/return-types

14 files changed, 178 insertions, 330 deletions

diff --git a/apps/dav/tests/unit/Connector/Sabre/DirectoryTest.php b/apps/dav/tests/unit/Connector/Sabre/DirectoryTest.php
index fb180b7c65d..2e19aec95e8 100644
--- a/apps/dav/tests/unit/Connector/Sabre/DirectoryTest.php
+++ b/apps/dav/tests/unit/Connector/Sabre/DirectoryTest.php
@@ -283,8 +283,8 @@ class DirectoryTest extends \Test\TestCase {
 		$storage->expects($this->any())
 			->method('instanceOfStorage')
 			->willReturnMap([
-				'\OCA\Files_Sharing\SharedStorage' => false,
-				'\OC\Files\Storage\Wrapper\Quota' => false,
+				['\OCA\Files_Sharing\SharedStorage', false],
+				['\OC\Files\Storage\Wrapper\Quota', false],
 			]);
 
 		$storage->expects($this->once())
diff --git a/apps/files_external/lib/Lib/Storage/AmazonS3.php b/apps/files_external/lib/Lib/Storage/AmazonS3.php
index 5325b25a66b..b2d6d24db5e 100644
--- a/apps/files_external/lib/Lib/Storage/AmazonS3.php
+++ b/apps/files_external/lib/Lib/Storage/AmazonS3.php
@@ -28,7 +28,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 
 	private LoggerInterface $logger;
 
-	public function needsPartFile() {
+	public function needsPartFile(): bool {
 		return false;
 	}
 
@@ -63,7 +63,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 	 * @param string $path
 	 * @return string correctly encoded path
 	 */
-	private function normalizePath($path) {
+	private function normalizePath($path): string {
 		$path = trim($path, '/');
 
 		if (!$path) {
@@ -73,24 +73,24 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		return $path;
 	}
 
-	private function isRoot($path) {
+	private function isRoot($path): bool {
 		return $path === '.';
 	}
 
-	private function cleanKey($path) {
+	private function cleanKey($path): string {
 		if ($this->isRoot($path)) {
 			return '/';
 		}
 		return $path;
 	}
 
-	private function clearCache() {
+	private function clearCache(): void {
 		$this->objectCache = new CappedMemoryCache();
 		$this->directoryCache = new CappedMemoryCache();
 		$this->filesCache = new CappedMemoryCache();
 	}
 
-	private function invalidateCache($key) {
+	private function invalidateCache($key): void {
 		unset($this->objectCache[$key]);
 		$keys = array_keys($this->objectCache->getData());
 		$keyLength = strlen($key);
@@ -110,10 +110,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		unset($this->directoryCache[$key]);
 	}
 
-	/**
-	 * @return array|false
-	 */
-	private function headObject(string $key) {
+	private function headObject(string $key): array|false {
 		if (!isset($this->objectCache[$key])) {
 			try {
 				$this->objectCache[$key] = $this->getConnection()->headObject([
@@ -144,11 +141,9 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 	 * Implementation from flysystem-aws-s3-v3:
 	 * https://github.com/thephpleague/flysystem-aws-s3-v3/blob/8241e9cc5b28f981e0d24cdaf9867f14c7498ae4/src/AwsS3Adapter.php#L670-L694
 	 *
-	 * @param $path
-	 * @return bool
 	 * @throws \Exception
 	 */
-	private function doesDirectoryExist($path) {
+	private function doesDirectoryExist($path): bool {
 		if ($path === '.' || $path === '') {
 			return true;
 		}
@@ -190,13 +185,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		return false;
 	}
 
-	/**
-	 * Remove a file or folder
-	 *
-	 * @param string $path
-	 * @return bool
-	 */
-	protected function remove($path) {
+	protected function remove($path): bool {
 		// remember fileType to reduce http calls
 		$fileType = $this->filetype($path);
 		if ($fileType === 'dir') {
@@ -208,7 +197,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		}
 	}
 
-	public function mkdir($path) {
+	public function mkdir($path): bool {
 		$path = $this->normalizePath($path);
 
 		if ($this->is_dir($path)) {
@@ -236,12 +225,12 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		return true;
 	}
 
-	public function file_exists($path) {
+	public function file_exists($path): bool {
 		return $this->filetype($path) !== false;
 	}
 
 
-	public function rmdir($path) {
+	public function rmdir($path): bool {
 		$path = $this->normalizePath($path);
 
 		if ($this->isRoot($path)) {
@@ -256,12 +245,12 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		return $this->batchDelete($path);
 	}
 
-	protected function clearBucket() {
+	protected function clearBucket(): bool {
 		$this->clearCache();
 		return $this->batchDelete();
 	}
 
-	private function batchDelete($path = null) {
+	private function batchDelete($path = null): bool {
 		// TODO explore using https://docs.aws.amazon.com/aws-sdk-php/v3/api/class-Aws.S3.BatchDelete.html
 		$params = [
 			'Bucket' => $this->bucket
@@ -312,7 +301,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		}
 	}
 
-	public function stat($path) {
+	public function stat($path): array|false {
 		$path = $this->normalizePath($path);
 
 		if ($this->is_dir($path)) {
@@ -334,11 +323,8 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 	 *
 	 * When the information is already present (e.g. opendir has been called before)
 	 * this value is return. Otherwise a headObject is emitted.
-	 *
-	 * @param $path
-	 * @return int|mixed
 	 */
-	private function getContentLength($path) {
+	private function getContentLength($path): int {
 		if (isset($this->filesCache[$path])) {
 			return (int)$this->filesCache[$path]['ContentLength'];
 		}
@@ -356,11 +342,8 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 	 *
 	 * When the information is already present (e.g. opendir has been called before)
 	 * this value is return. Otherwise a headObject is emitted.
-	 *
-	 * @param $path
-	 * @return mixed|string
 	 */
-	private function getLastModified($path) {
+	private function getLastModified($path): string {
 		if (isset($this->filesCache[$path])) {
 			return $this->filesCache[$path]['LastModified'];
 		}
@@ -373,7 +356,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		return 'now';
 	}
 
-	public function is_dir($path) {
+	public function is_dir($path): bool {
 		$path = $this->normalizePath($path);
 
 		if (isset($this->filesCache[$path])) {
@@ -391,7 +374,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		}
 	}
 
-	public function filetype($path) {
+	public function filetype($path): string|false {
 		$path = $this->normalizePath($path);
 
 		if ($this->isRoot($path)) {
@@ -419,7 +402,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		return false;
 	}
 
-	public function getPermissions($path) {
+	public function getPermissions($path): int {
 		$type = $this->filetype($path);
 		if (!$type) {
 			return 0;
@@ -427,7 +410,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		return $type === 'dir' ? Constants::PERMISSION_ALL : Constants::PERMISSION_ALL - Constants::PERMISSION_CREATE;
 	}
 
-	public function unlink($path) {
+	public function unlink($path): bool {
 		$path = $this->normalizePath($path);
 
 		if ($this->is_dir($path)) {
@@ -506,7 +489,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		return false;
 	}
 
-	public function touch($path, $mtime = null) {
+	public function touch($path, $mtime = null): bool {
 		if (is_null($mtime)) {
 			$mtime = time();
 		}
@@ -541,7 +524,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		return true;
 	}
 
-	public function copy($source, $target, $isFile = null) {
+	public function copy($source, $target, $isFile = null): bool {
 		$source = $this->normalizePath($source);
 		$target = $this->normalizePath($target);
 
@@ -584,7 +567,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		return true;
 	}
 
-	public function rename($source, $target) {
+	public function rename($source, $target): bool {
 		$source = $this->normalizePath($source);
 		$target = $this->normalizePath($target);
 
@@ -611,18 +594,18 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		return true;
 	}
 
-	public function test() {
+	public function test(): bool {
 		$this->getConnection()->headBucket([
 			'Bucket' => $this->bucket
 		]);
 		return true;
 	}
 
-	public function getId() {
+	public function getId(): string {
 		return $this->id;
 	}
 
-	public function writeBack($tmpFile, $path) {
+	public function writeBack($tmpFile, $path): bool {
 		try {
 			$source = fopen($tmpFile, 'r');
 			$this->writeObject($path, $source, $this->mimeDetector->detectPath($path));
@@ -642,7 +625,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 	/**
 	 * check if curl is installed
 	 */
-	public static function checkDependencies() {
+	public static function checkDependencies(): bool {
 		return true;
 	}
 
@@ -743,7 +726,7 @@ class AmazonS3 extends \OC\Files\Storage\Common {
 		}
 	}
 
-	public function hasUpdated($path, $time) {
+	public function hasUpdated($path, $time): bool {
 		// for files we can get the proper mtime
 		if ($path !== '' && $object = $this->headObject($path)) {
 			$stat = $this->objectToMetaData($object);
diff --git a/apps/files_external/lib/Lib/Storage/FTP.php b/apps/files_external/lib/Lib/Storage/FTP.php
index a7a348cbf43..514492156b6 100644
--- a/apps/files_external/lib/Lib/Storage/FTP.php
+++ b/apps/files_external/lib/Lib/Storage/FTP.php
@@ -78,15 +78,15 @@ class FTP extends Common {
 		return $this->connection;
 	}
 
-	public function getId() {
+	public function getId(): string {
 		return 'ftp::' . $this->username . '@' . $this->host . '/' . $this->root;
 	}
 
-	protected function buildPath($path) {
+	protected function buildPath($path): string {
 		return rtrim($this->root . '/' . $path, '/');
 	}
 
-	public static function checkDependencies() {
+	public static function checkDependencies(): array|bool {
 		if (function_exists('ftp_login')) {
 			return true;
 		} else {
@@ -94,7 +94,7 @@ class FTP extends Common {
 		}
 	}
 
-	public function filemtime($path) {
+	public function filemtime($path): int|false {
 		$result = $this->getConnection()->mdtm($this->buildPath($path));
 
 		if ($result === -1) {
@@ -135,7 +135,7 @@ class FTP extends Common {
 		}
 	}
 
-	public function rmdir($path) {
+	public function rmdir($path): bool {
 		if ($this->is_dir($path)) {
 			$result = $this->getConnection()->rmdir($this->buildPath($path));
 			// recursive rmdir support depends on the ftp server
@@ -153,7 +153,6 @@ class FTP extends Common {
 
 	/**
 	 * @param string $path
-	 * @return bool
 	 */
 	private function recursiveRmDir($path): bool {
 		$contents = $this->getDirectoryContent($path);
@@ -170,7 +169,7 @@ class FTP extends Common {
 		return $result;
 	}
 
-	public function test() {
+	public function test(): bool {
 		try {
 			return $this->getConnection()->systype() !== false;
 		} catch (\Exception $e) {
@@ -178,7 +177,7 @@ class FTP extends Common {
 		}
 	}
 
-	public function stat($path) {
+	public function stat($path): array|false {
 		if (!$this->file_exists($path)) {
 			return false;
 		}
@@ -188,14 +187,14 @@ class FTP extends Common {
 		];
 	}
 
-	public function file_exists($path) {
+	public function file_exists($path): bool {
 		if ($path === '' || $path === '.' || $path === '/') {
 			return true;
 		}
 		return $this->filetype($path) !== false;
 	}
 
-	public function unlink($path) {
+	public function unlink($path): bool {
 		switch ($this->filetype($path)) {
 			case 'dir':
 				return $this->rmdir($path);
@@ -211,14 +210,14 @@ class FTP extends Common {
 		return IteratorDirectory::wrap($files);
 	}
 
-	public function mkdir($path) {
+	public function mkdir($path): bool {
 		if ($this->is_dir($path)) {
 			return false;
 		}
 		return $this->getConnection()->mkdir($this->buildPath($path)) !== false;
 	}
 
-	public function is_dir($path) {
+	public function is_dir($path): bool {
 		if ($path === '') {
 			return true;
 		}
@@ -230,11 +229,11 @@ class FTP extends Common {
 		}
 	}
 
-	public function is_file($path) {
+	public function is_file($path): bool {
 		return $this->filesize($path) !== false;
 	}
 
-	public function filetype($path) {
+	public function filetype($path): string|false {
 		if ($this->is_dir($path)) {
 			return 'dir';
 		} elseif ($this->is_file($path)) {
@@ -310,7 +309,7 @@ class FTP extends Common {
 		return $stream;
 	}
 
-	public function touch($path, $mtime = null) {
+	public function touch($path, $mtime = null): bool {
 		if ($this->file_exists($path)) {
 			return false;
 		} else {
@@ -319,7 +318,7 @@ class FTP extends Common {
 		}
 	}
 
-	public function rename($source, $target) {
+	public function rename($source, $target): bool {
 		$this->unlink($target);
 		return $this->getConnection()->rename($this->buildPath($source), $this->buildPath($target));
 	}
diff --git a/apps/files_external/lib/Lib/Storage/OwnCloud.php b/apps/files_external/lib/Lib/Storage/OwnCloud.php
index fb5c7207486..5de708afb04 100644
--- a/apps/files_external/lib/Lib/Storage/OwnCloud.php
+++ b/apps/files_external/lib/Lib/Storage/OwnCloud.php
@@ -55,7 +55,7 @@ class OwnCloud extends \OC\Files\Storage\DAV implements IDisableEncryptionStorag
 		parent::__construct($params);
 	}
 
-	public function needsPartFile() {
+	public function needsPartFile(): bool {
 		return false;
 	}
 }
diff --git a/apps/files_external/lib/Lib/Storage/SFTP.php b/apps/files_external/lib/Lib/Storage/SFTP.php
index a6a28245214..c8e01a058ff 100644
--- a/apps/files_external/lib/Lib/Storage/SFTP.php
+++ b/apps/files_external/lib/Lib/Storage/SFTP.php
@@ -39,7 +39,7 @@ class SFTP extends Common {
 	 * @param string $host protocol://server:port
 	 * @return array [$server, $port]
 	 */
-	private function splitHost($host) {
+	private function splitHost($host): array {
 		$input = $host;
 		if (!str_contains($host, '://')) {
 			// add a protocol to fix parse_url behavior with ipv6
@@ -56,9 +56,6 @@ class SFTP extends Common {
 		}
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
 	public function __construct($params) {
 		// Register sftp://
 		Stream::register();
@@ -98,7 +95,7 @@ class SFTP extends Common {
 	 * @return \phpseclib\Net\SFTP connected client instance
 	 * @throws \Exception when the connection failed
 	 */
-	public function getConnection() {
+	public function getConnection(): \phpseclib\Net\SFTP {
 		if (!is_null($this->client)) {
 			return $this->client;
 		}
@@ -132,10 +129,7 @@ class SFTP extends Common {
 		return $this->client;
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
-	public function test() {
+	public function test(): bool {
 		if (
 			!isset($this->host)
 			|| !isset($this->user)
@@ -145,10 +139,7 @@ class SFTP extends Common {
 		return $this->getConnection()->nlist() !== false;
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
-	public function getId() {
+	public function getId(): string {
 		$id = 'sftp::' . $this->user . '@' . $this->host;
 		if ($this->port !== 22) {
 			$id .= ':' . $this->port;
@@ -160,39 +151,26 @@ class SFTP extends Common {
 		return $id;
 	}
 
-	/**
-	 * @return string
-	 */
-	public function getHost() {
+	public function getHost(): string {
 		return $this->host;
 	}
 
-	/**
-	 * @return string
-	 */
-	public function getRoot() {
+	public function getRoot(): string {
 		return $this->root;
 	}
 
-	/**
-	 * @return mixed
-	 */
-	public function getUser() {
+	public function getUser(): string {
 		return $this->user;
 	}
 
 	/**
 	 * @param string $path
-	 * @return string
 	 */
-	private function absPath($path) {
+	private function absPath($path): string {
 		return $this->root . $this->cleanPath($path);
 	}
 
-	/**
-	 * @return string|false
-	 */
-	private function hostKeysPath() {
+	private function hostKeysPath(): string|false {
 		try {
 			$userId = \OC_User::getUser();
 			if ($userId === false) {
@@ -207,11 +185,7 @@ class SFTP extends Common {
 		return false;
 	}
 
-	/**
-	 * @param $keys
-	 * @return bool
-	 */
-	protected function writeHostKeys($keys) {
+	protected function writeHostKeys($keys): bool {
 		try {
 			$keyPath = $this->hostKeysPath();
 			if ($keyPath && file_exists($keyPath)) {
@@ -227,10 +201,7 @@ class SFTP extends Common {
 		return false;
 	}
 
-	/**
-	 * @return array
-	 */
-	protected function readHostKeys() {
+	protected function readHostKeys(): array {
 		try {
 			$keyPath = $this->hostKeysPath();
 			if (file_exists($keyPath)) {
@@ -253,10 +224,7 @@ class SFTP extends Common {
 		return [];
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
-	public function mkdir($path) {
+	public function mkdir($path): bool {
 		try {
 			return $this->getConnection()->mkdir($this->absPath($path));
 		} catch (\Exception $e) {
@@ -264,10 +232,7 @@ class SFTP extends Common {
 		}
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
-	public function rmdir($path) {
+	public function rmdir($path): bool {
 		try {
 			$result = $this->getConnection()->delete($this->absPath($path), true);
 			// workaround: stray stat cache entry when deleting empty folders
@@ -279,9 +244,6 @@ class SFTP extends Common {
 		}
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
 	public function opendir($path) {
 		try {
 			$list = $this->getConnection()->nlist($this->absPath($path));
@@ -302,10 +264,7 @@ class SFTP extends Common {
 		}
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
-	public function filetype($path) {
+	public function filetype($path): string|false {
 		try {
 			$stat = $this->getConnection()->stat($this->absPath($path));
 			if (!is_array($stat) || !array_key_exists('type', $stat)) {
@@ -323,10 +282,7 @@ class SFTP extends Common {
 		return false;
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
-	public function file_exists($path) {
+	public function file_exists($path): bool {
 		try {
 			return $this->getConnection()->stat($this->absPath($path)) !== false;
 		} catch (\Exception $e) {
@@ -334,10 +290,7 @@ class SFTP extends Common {
 		}
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
-	public function unlink($path) {
+	public function unlink($path): bool {
 		try {
 			return $this->getConnection()->delete($this->absPath($path), true);
 		} catch (\Exception $e) {
@@ -345,9 +298,6 @@ class SFTP extends Common {
 		}
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
 	public function fopen($path, $mode) {
 		try {
 			$absPath = $this->absPath($path);
@@ -389,10 +339,7 @@ class SFTP extends Common {
 		return false;
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
-	public function touch($path, $mtime = null) {
+	public function touch($path, $mtime = null): bool {
 		try {
 			if (!is_null($mtime)) {
 				return false;
@@ -413,14 +360,11 @@ class SFTP extends Common {
 	 * @param string $target
 	 * @throws \Exception
 	 */
-	public function getFile($path, $target) {
+	public function getFile($path, $target): void {
 		$this->getConnection()->get($path, $target);
 	}
 
-	/**
-	 * {@inheritdoc}
-	 */
-	public function rename($source, $target) {
+	public function rename($source, $target): bool {
 		try {
 			if ($this->file_exists($target)) {
 				$this->unlink($target);
@@ -437,7 +381,7 @@ class SFTP extends Common {
 	/**
 	 * @return array{mtime: int, size: int, ctime: int}|false
 	 */
-	public function stat($path) {
+	public function stat($path): array|false {
 		try {
 			$stat = $this->getConnection()->stat($this->absPath($path));
 
@@ -456,9 +400,8 @@ class SFTP extends Common {
 
 	/**
 	 * @param string $path
-	 * @return string
 	 */
-	public function constructUrl($path) {
+	public function constructUrl($path): string {
 		// Do not pass the password here. We want to use the Net_SFTP object
 		// supplied via stream context or fail. We only supply username and
 		// hostname because this might show up in logs (they are not used).
@@ -466,7 +409,7 @@ class SFTP extends Common {
 		return $url;
 	}
 
-	public function file_put_contents($path, $data) {
+	public function file_put_contents($path, $data): int|float|false {
 		/** @psalm-suppress InternalMethod */
 		$result = $this->getConnection()->put($this->absPath($path), $data);
 		if ($result) {
@@ -498,7 +441,7 @@ class SFTP extends Common {
 		}
 	}
 
-	public function copy($source, $target) {
+	public function copy($source, $target): bool {
 		if ($this->is_dir($source) || $this->is_dir($target)) {
 			return parent::copy($source, $target);
 		} else {
@@ -525,7 +468,7 @@ class SFTP extends Common {
 		}
 	}
 
-	public function getPermissions($path) {
+	public function getPermissions($path): int {
 		$stat = $this->getConnection()->stat($this->absPath($path));
 		if (!$stat) {
 			return 0;
@@ -537,7 +480,7 @@ class SFTP extends Common {
 		}
 	}
 
-	public function getMetaData($path) {
+	public function getMetaData($path): ?array {
 		$stat = $this->getConnection()->stat($this->absPath($path));
 		if (!$stat) {
 			return null;
diff --git a/apps/files_external/lib/Lib/Storage/SMB.php b/apps/files_external/lib/Lib/Storage/SMB.php
index 91a6eab8d09..4f1f51f1bf9 100644
--- a/apps/files_external/lib/Lib/Storage/SMB.php
+++ b/apps/files_external/lib/Lib/Storage/SMB.php
@@ -118,7 +118,7 @@ class SMB extends Common implements INotifyStorage {
 		parent::__construct($params);
 	}
 
-	private function splitUser($user) {
+	private function splitUser($user): array {
 		if (str_contains($user, '/')) {
 			return explode('/', $user, 2);
 		} elseif (str_contains($user, '\\')) {
@@ -128,10 +128,7 @@ class SMB extends Common implements INotifyStorage {
 		return [null, $user];
 	}
 
-	/**
-	 * @return string
-	 */
-	public function getId() {
+	public function getId(): string {
 		// FIXME: double slash to keep compatible with the old storage ids,
 		// failure to do so will lead to creation of a new storage id and
 		// loss of shares from the storage
@@ -140,13 +137,12 @@ class SMB extends Common implements INotifyStorage {
 
 	/**
 	 * @param string $path
-	 * @return string
 	 */
-	protected function buildPath($path) {
+	protected function buildPath($path): string {
 		return Filesystem::normalizePath($this->root . '/' . $path, true, false, true);
 	}
 
-	protected function relativePath($fullPath) {
+	protected function relativePath($fullPath): ?string {
 		if ($fullPath === $this->root) {
 			return '';
 		} elseif (substr($fullPath, 0, strlen($this->root)) === $this->root) {
@@ -158,12 +154,11 @@ class SMB extends Common implements INotifyStorage {
 
 	/**
 	 * @param string $path
-	 * @return IFileInfo
 	 * @throws StorageAuthException
 	 * @throws \OCP\Files\NotFoundException
 	 * @throws \OCP\Files\ForbiddenException
 	 */
-	protected function getFileInfo($path) {
+	protected function getFileInfo($path): IFileInfo {
 		try {
 			$path = $this->buildPath($path);
 			$cached = $this->statCache[$path] ?? null;
@@ -190,10 +185,9 @@ class SMB extends Common implements INotifyStorage {
 
 	/**
 	 * @param \Exception $e
-	 * @return never
 	 * @throws StorageAuthException
 	 */
-	protected function throwUnavailable(\Exception $e) {
+	protected function throwUnavailable(\Exception $e): never {
 		$this->logger->error('Error while getting file info', ['exception' => $e]);
 		throw new StorageAuthException($e->getMessage(), $e);
 	}
@@ -202,7 +196,6 @@ class SMB extends Common implements INotifyStorage {
 	 * get the acl from fileinfo that is relevant for the configured user
 	 *
 	 * @param IFileInfo $file
-	 * @return ACL|null
 	 */
 	private function getACL(IFileInfo $file): ?ACL {
 		$acls = $file->getAcls();
@@ -274,9 +267,8 @@ class SMB extends Common implements INotifyStorage {
 
 	/**
 	 * @param IFileInfo $info
-	 * @return array
 	 */
-	protected function formatInfo($info) {
+	protected function formatInfo($info): array {
 		$result = [
 			'size' => $info->getSize(),
 			'mtime' => $info->getMTime(),
@@ -294,7 +286,6 @@ class SMB extends Common implements INotifyStorage {
 	 *
 	 * @param string $source the old name of the path
 	 * @param string $target the new name of the path
-	 * @return bool true if the rename is successful, false otherwise
 	 */
 	public function rename($source, $target, $retry = true): bool {
 		if ($this->isRootDir($source) || $this->isRootDir($target)) {
@@ -335,7 +326,7 @@ class SMB extends Common implements INotifyStorage {
 		return $result;
 	}
 
-	public function stat($path, $retry = true) {
+	public function stat($path, $retry = true): array|false {
 		try {
 			$result = $this->formatInfo($this->getFileInfo($path));
 		} catch (\OCP\Files\ForbiddenException $e) {
@@ -357,10 +348,8 @@ class SMB extends Common implements INotifyStorage {
 
 	/**
 	 * get the best guess for the modification time of the share
-	 *
-	 * @return int
 	 */
-	private function shareMTime() {
+	private function shareMTime(): int {
 		$highestMTime = 0;
 		$files = $this->share->dir($this->root);
 		foreach ($files as $fileInfo) {
@@ -381,26 +370,22 @@ class SMB extends Common implements INotifyStorage {
 	 * Check if the path is our root dir (not the smb one)
 	 *
 	 * @param string $path the path
-	 * @return bool
 	 */
-	private function isRootDir($path) {
+	private function isRootDir($path): bool {
 		return $path === '' || $path === '/' || $path === '.';
 	}
 
 	/**
 	 * Check if our root points to a smb share
-	 *
-	 * @return bool true if our root points to a share false otherwise
 	 */
-	private function remoteIsShare() {
+	private function remoteIsShare(): bool {
 		return $this->share->getName() && (!$this->root || $this->root === '/');
 	}
 
 	/**
 	 * @param string $path
-	 * @return bool
 	 */
-	public function unlink($path) {
+	public function unlink($path): bool {
 		if ($this->isRootDir($path)) {
 			return false;
 		}
@@ -429,9 +414,8 @@ class SMB extends Common implements INotifyStorage {
 	 *
 	 * @param string $path
 	 * @param int $time
-	 * @return bool
 	 */
-	public function hasUpdated($path, $time) {
+	public function hasUpdated($path, $time): bool {
 		if (!$path and $this->root === '/') {
 			// mtime doesn't work for shares, but giving the nature of the backend,
 			// doing a full update is still just fast enough
@@ -445,7 +429,7 @@ class SMB extends Common implements INotifyStorage {
 	/**
 	 * @param string $path
 	 * @param string $mode
-	 * @return resource|bool
+	 * @return resource|false
 	 */
 	public function fopen($path, $mode) {
 		$fullPath = $this->buildPath($path);
@@ -511,7 +495,7 @@ class SMB extends Common implements INotifyStorage {
 		}
 	}
 
-	public function rmdir($path) {
+	public function rmdir($path): bool {
 		if ($this->isRootDir($path)) {
 			return false;
 		}
@@ -538,7 +522,7 @@ class SMB extends Common implements INotifyStorage {
 		}
 	}
 
-	public function touch($path, $mtime = null) {
+	public function touch($path, $mtime = null): bool {
 		try {
 			if (!$this->file_exists($path)) {
 				$fh = $this->share->write($this->buildPath($path));
@@ -554,7 +538,7 @@ class SMB extends Common implements INotifyStorage {
 		}
 	}
 
-	public function getMetaData($path) {
+	public function getMetaData($path): ?array {
 		try {
 			$fileInfo = $this->getFileInfo($path);
 		} catch (\OCP\Files\NotFoundException $e) {
@@ -562,14 +546,11 @@ class SMB extends Common implements INotifyStorage {
 		} catch (\OCP\Files\ForbiddenException $e) {
 			return null;
 		}
-		if (!$fileInfo) {
-			return null;
-		}
 
 		return $this->getMetaDataFromFileInfo($fileInfo);
 	}
 
-	private function getMetaDataFromFileInfo(IFileInfo $fileInfo) {
+	private function getMetaDataFromFileInfo(IFileInfo $fileInfo): array {
 		$permissions = Constants::PERMISSION_READ + Constants::PERMISSION_SHARE;
 
 		if (
@@ -630,7 +611,7 @@ class SMB extends Common implements INotifyStorage {
 		}
 	}
 
-	public function filetype($path) {
+	public function filetype($path): string|false {
 		try {
 			return $this->getFileInfo($path)->isDirectory() ? 'dir' : 'file';
 		} catch (\OCP\Files\NotFoundException $e) {
@@ -640,7 +621,7 @@ class SMB extends Common implements INotifyStorage {
 		}
 	}
 
-	public function mkdir($path) {
+	public function mkdir($path): bool {
 		$path = $this->buildPath($path);
 		try {
 			$this->share->mkdir($path);
@@ -653,7 +634,7 @@ class SMB extends Common implements INotifyStorage {
 		}
 	}
 
-	public function file_exists($path) {
+	public function file_exists($path): bool {
 		try {
 			// Case sensitive filesystem doesn't matter for root directory
 			if ($this->caseSensitive === false && $path !== '') {
@@ -677,7 +658,7 @@ class SMB extends Common implements INotifyStorage {
 		}
 	}
 
-	public function isReadable($path) {
+	public function isReadable($path): bool {
 		try {
 			$info = $this->getFileInfo($path);
 			return $this->showHidden || !$info->isHidden();
@@ -688,7 +669,7 @@ class SMB extends Common implements INotifyStorage {
 		}
 	}
 
-	public function isUpdatable($path) {
+	public function isUpdatable($path): bool {
 		try {
 			$info = $this->getFileInfo($path);
 			// following windows behaviour for read-only folders: they can be written into
@@ -701,7 +682,7 @@ class SMB extends Common implements INotifyStorage {
 		}
 	}
 
-	public function isDeletable($path) {
+	public function isDeletable($path): bool {
 		try {
 			$info = $this->getFileInfo($path);
 			return ($this->showHidden || !$info->isHidden()) && !$info->isReadOnly();
@@ -715,19 +696,14 @@ class SMB extends Common implements INotifyStorage {
 	/**
 	 * check if smbclient is installed
 	 */
-	public static function checkDependencies() {
+	public static function checkDependencies(): array|bool {
 		return (
 			(bool)\OC_Helper::findBinaryPath('smbclient')
 			|| NativeServer::available(new System())
 		) ? true : ['smbclient'];
 	}
 
-	/**
-	 * Test a storage for availability
-	 *
-	 * @return bool
-	 */
-	public function test() {
+	public function test(): bool {
 		try {
 			return parent::test();
 		} catch (StorageAuthException $e) {
@@ -740,7 +716,7 @@ class SMB extends Common implements INotifyStorage {
 		}
 	}
 
-	public function listen($path, callable $callback) {
+	public function listen($path, callable $callback): void {
 		$this->notify($path)->listen(function (IChange $change) use ($callback) {
 			if ($change instanceof IRenameChange) {
 				return $callback($change->getType(), $change->getPath(), $change->getTargetPath());
@@ -750,7 +726,7 @@ class SMB extends Common implements INotifyStorage {
 		});
 	}
 
-	public function notify($path) {
+	public function notify($path): SMBNotifyHandler {
 		$path = '/' . ltrim($path, '/');
 		$shareNotifyHandler = $this->share->notify($this->buildPath($path));
 		return new SMBNotifyHandler($shareNotifyHandler, $this->root);
diff --git a/apps/files_external/lib/Lib/Storage/StreamWrapper.php b/apps/files_external/lib/Lib/Storage/StreamWrapper.php
index 2928c081505..96a306e4f53 100644
--- a/apps/files_external/lib/Lib/Storage/StreamWrapper.php
+++ b/apps/files_external/lib/Lib/Storage/StreamWrapper.php
@@ -12,13 +12,13 @@ abstract class StreamWrapper extends \OC\Files\Storage\Common {
 	 * @param string $path
 	 * @return string|null
 	 */
-	abstract public function constructUrl($path);
+	abstract public function constructUrl($path): ?string;
 
-	public function mkdir($path) {
+	public function mkdir($path): bool {
 		return mkdir($this->constructUrl($path));
 	}
 
-	public function rmdir($path) {
+	public function rmdir($path): bool {
 		if ($this->is_dir($path) && $this->isDeletable($path)) {
 			$dh = $this->opendir($path);
 			if (!is_resource($dh)) {
@@ -44,15 +44,15 @@ abstract class StreamWrapper extends \OC\Files\Storage\Common {
 		return opendir($this->constructUrl($path));
 	}
 
-	public function filetype($path) {
+	public function filetype($path): string|false {
 		return @filetype($this->constructUrl($path));
 	}
 
-	public function file_exists($path) {
+	public function file_exists($path): bool {
 		return file_exists($this->constructUrl($path));
 	}
 
-	public function unlink($path) {
+	public function unlink($path): bool {
 		$url = $this->constructUrl($path);
 		$success = unlink($url);
 		// normally unlink() is supposed to do this implicitly,
@@ -65,7 +65,7 @@ abstract class StreamWrapper extends \OC\Files\Storage\Common {
 		return fopen($this->constructUrl($path), $mode);
 	}
 
-	public function touch($path, $mtime = null) {
+	public function touch($path, $mtime = null): bool {
 		if ($this->file_exists($path)) {
 			if (is_null($mtime)) {
 				$fh = $this->fopen($path, 'a');
@@ -86,22 +86,22 @@ abstract class StreamWrapper extends \OC\Files\Storage\Common {
 	 * @param string $path
 	 * @param string $target
 	 */
-	public function getFile($path, $target) {
+	public function getFile($path, $target): bool {
 		return copy($this->constructUrl($path), $target);
 	}
 
 	/**
 	 * @param string $target
 	 */
-	public function uploadFile($path, $target) {
+	public function uploadFile($path, $target): bool {
 		return copy($path, $this->constructUrl($target));
 	}
 
-	public function rename($source, $target) {
+	public function rename($source, $target): bool {
 		return rename($this->constructUrl($source), $this->constructUrl($target));
 	}
 
-	public function stat($path) {
+	public function stat($path): array|false {
 		return stat($this->constructUrl($path));
 	}
 }
diff --git a/apps/files_external/lib/Lib/Storage/Swift.php b/apps/files_external/lib/Lib/Storage/Swift.php
index 9aabf5b56b4..3582470b3be 100644
--- a/apps/files_external/lib/Lib/Storage/Swift.php
+++ b/apps/files_external/lib/Lib/Storage/Swift.php
@@ -16,6 +16,7 @@ use OC\Files\ObjectStore\SwiftFactory;
 use OCP\Files\IMimeTypeDetector;
 use OCP\Files\StorageBadConfigException;
 use OpenStack\Common\Error\BadResponseError;
+use OpenStack\ObjectStore\v1\Models\Container;
 use OpenStack\ObjectStore\v1\Models\StorageObject;
 use Psr\Log\LoggerInterface;
 
@@ -23,7 +24,7 @@ class Swift extends \OC\Files\Storage\Common {
 	/** @var SwiftFactory */
 	private $connectionFactory;
 	/**
-	 * @var \OpenStack\ObjectStore\v1\Models\Container
+	 * @var Container
 	 */
 	private $container;
 	/**
@@ -55,11 +56,7 @@ class Swift extends \OC\Files\Storage\Common {
 	 */
 	private $objectCache;
 
-	/**
-	 * @param string $path
-	 * @return mixed|string
-	 */
-	private function normalizePath(string $path) {
+	private function normalizePath(string $path): string {
 		$path = trim($path, '/');
 
 		if (!$path) {
@@ -87,12 +84,12 @@ class Swift extends \OC\Files\Storage\Common {
 	 * that one will be returned.
 	 *
 	 * @param string $path
-	 * @return StorageObject|bool object
-	 *                            or false if the object did not exist
+	 * @return StorageObject|false object
+	 *                             or false if the object did not exist
 	 * @throws \OCP\Files\StorageAuthException
 	 * @throws \OCP\Files\StorageNotAvailableException
 	 */
-	private function fetchObject(string $path) {
+	private function fetchObject(string $path): StorageObject|false {
 		$cached = $this->objectCache->get($path);
 		if ($cached !== null) {
 			// might be "false" if object did not exist from last check
@@ -125,7 +122,7 @@ class Swift extends \OC\Files\Storage\Common {
 	 * @throws \OCP\Files\StorageAuthException
 	 * @throws \OCP\Files\StorageNotAvailableException
 	 */
-	private function doesObjectExist($path) {
+	private function doesObjectExist($path): bool {
 		return $this->fetchObject($path) !== false;
 	}
 
@@ -179,7 +176,7 @@ class Swift extends \OC\Files\Storage\Common {
 		$this->mimeDetector = \OC::$server->get(IMimeTypeDetector::class);
 	}
 
-	public function mkdir($path) {
+	public function mkdir($path): bool {
 		$path = $this->normalizePath($path);
 
 		if ($this->is_dir($path)) {
@@ -210,7 +207,7 @@ class Swift extends \OC\Files\Storage\Common {
 		return true;
 	}
 
-	public function file_exists($path) {
+	public function file_exists($path): bool {
 		$path = $this->normalizePath($path);
 
 		if ($path !== '.' && $this->is_dir($path)) {
@@ -220,7 +217,7 @@ class Swift extends \OC\Files\Storage\Common {
 		return $this->doesObjectExist($path);
 	}
 
-	public function rmdir($path) {
+	public function rmdir($path): bool {
 		$path = $this->normalizePath($path);
 
 		if (!$this->is_dir($path) || !$this->isDeletable($path)) {
@@ -290,7 +287,7 @@ class Swift extends \OC\Files\Storage\Common {
 		}
 	}
 
-	public function stat($path) {
+	public function stat($path): array|false {
 		$path = $this->normalizePath($path);
 
 		if ($path === '.') {
@@ -346,7 +343,7 @@ class Swift extends \OC\Files\Storage\Common {
 		}
 	}
 
-	public function unlink($path) {
+	public function unlink($path): bool {
 		$path = $this->normalizePath($path);
 
 		if ($this->is_dir($path)) {
@@ -420,7 +417,7 @@ class Swift extends \OC\Files\Storage\Common {
 		}
 	}
 
-	public function touch($path, $mtime = null) {
+	public function touch($path, $mtime = null): bool {
 		$path = $this->normalizePath($path);
 		if (is_null($mtime)) {
 			$mtime = time();
@@ -450,7 +447,7 @@ class Swift extends \OC\Files\Storage\Common {
 		}
 	}
 
-	public function copy($source, $target) {
+	public function copy($source, $target): bool {
 		$source = $this->normalizePath($source);
 		$target = $this->normalizePath($target);
 
@@ -511,7 +508,7 @@ class Swift extends \OC\Files\Storage\Common {
 		return true;
 	}
 
-	public function rename($source, $target) {
+	public function rename($source, $target): bool {
 		$source = $this->normalizePath($source);
 		$target = $this->normalizePath($target);
 
@@ -536,18 +533,18 @@ class Swift extends \OC\Files\Storage\Common {
 		return false;
 	}
 
-	public function getId() {
+	public function getId(): string {
 		return $this->id;
 	}
 
 	/**
 	 * Returns the initialized object store container.
 	 *
-	 * @return \OpenStack\ObjectStore\v1\Models\Container
+	 * @return Container
 	 * @throws \OCP\Files\StorageAuthException
 	 * @throws \OCP\Files\StorageNotAvailableException
 	 */
-	public function getContainer() {
+	public function getContainer(): Container {
 		if (is_null($this->container)) {
 			$this->container = $this->connectionFactory->getContainer();
 
@@ -558,7 +555,7 @@ class Swift extends \OC\Files\Storage\Common {
 		return $this->container;
 	}
 
-	public function writeBack($tmpFile, $path) {
+	public function writeBack($tmpFile, $path): void {
 		$fileData = fopen($tmpFile, 'r');
 		$this->objectStore->writeObject($path, $fileData, $this->mimeDetector->detectPath($path));
 		// invalidate target object to force repopulation on fetch
@@ -566,7 +563,7 @@ class Swift extends \OC\Files\Storage\Common {
 		unlink($tmpFile);
 	}
 
-	public function hasUpdated($path, $time) {
+	public function hasUpdated($path, $time): bool {
 		if ($this->is_file($path)) {
 			return parent::hasUpdated($path, $time);
 		}
@@ -591,7 +588,7 @@ class Swift extends \OC\Files\Storage\Common {
 	/**
 	 * check if curl is installed
 	 */
-	public static function checkDependencies() {
+	public static function checkDependencies(): bool {
 		return true;
 	}
 }
diff --git a/apps/files_sharing/lib/External/Storage.php b/apps/files_sharing/lib/External/Storage.php
index 6e5e219ae69..718afbf7499 100644
--- a/apps/files_sharing/lib/External/Storage.php
+++ b/apps/files_sharing/lib/External/Storage.php
@@ -18,6 +18,9 @@ use OCA\Files_Sharing\ISharedStorage;
 use OCP\AppFramework\Http;
 use OCP\Constants;
 use OCP\Federation\ICloudId;
+use OCP\Files\Cache\ICache;
+use OCP\Files\Cache\IScanner;
+use OCP\Files\Cache\IWatcher;
 use OCP\Files\NotFoundException;
 use OCP\Files\Storage\IDisableEncryptionStorage;
 use OCP\Files\Storage\IReliableEtagStorage;
@@ -91,7 +94,7 @@ class Storage extends DAV implements ISharedStorage, IDisableEncryptionStorage,
 		);
 	}
 
-	public function getWatcher($path = '', $storage = null) {
+	public function getWatcher($path = '', $storage = null): IWatcher {
 		if (!$storage) {
 			$storage = $this;
 		}
@@ -122,22 +125,18 @@ class Storage extends DAV implements ISharedStorage, IDisableEncryptionStorage,
 		return $this->password;
 	}
 
-	/**
-	 * Get id of the mount point.
-	 * @return string
-	 */
-	public function getId() {
+	public function getId(): string {
 		return 'shared::' . md5($this->token . '@' . $this->getRemote());
 	}
 
-	public function getCache($path = '', $storage = null) {
+	public function getCache($path = '', $storage = null): ICache {
 		if (is_null($this->cache)) {
 			$this->cache = new Cache($this, $this->cloudId);
 		}
 		return $this->cache;
 	}
 
-	public function getScanner($path = '', $storage = null) {
+	public function getScanner($path = '', $storage = null): IScanner {
 		if (!$storage) {
 			$storage = $this;
 		}
@@ -148,16 +147,7 @@ class Storage extends DAV implements ISharedStorage, IDisableEncryptionStorage,
 		return $this->scanner;
 	}
 
-	/**
-	 * Check if a file or folder has been updated since $time
-	 *
-	 * @param string $path
-	 * @param int $time
-	 * @throws \OCP\Files\StorageNotAvailableException
-	 * @throws \OCP\Files\StorageInvalidException
-	 * @return bool
-	 */
-	public function hasUpdated($path, $time) {
+	public function hasUpdated($path, $time): bool {
 		// since for owncloud webdav servers we can rely on etag propagation we only need to check the root of the storage
 		// because of that we only do one check for the entire storage per request
 		if ($this->updateChecked) {
@@ -177,7 +167,7 @@ class Storage extends DAV implements ISharedStorage, IDisableEncryptionStorage,
 		}
 	}
 
-	public function test() {
+	public function test(): bool {
 		try {
 			return parent::test();
 		} catch (StorageInvalidException $e) {
@@ -227,7 +217,7 @@ class Storage extends DAV implements ISharedStorage, IDisableEncryptionStorage,
 		}
 	}
 
-	public function file_exists($path) {
+	public function file_exists($path): bool {
 		if ($path === '') {
 			return true;
 		} else {
@@ -368,7 +358,7 @@ class Storage extends DAV implements ISharedStorage, IDisableEncryptionStorage,
 		return $permissions;
 	}
 
-	public function needsPartFile() {
+	public function needsPartFile(): bool {
 		return false;
 	}
 
@@ -418,7 +408,7 @@ class Storage extends DAV implements ISharedStorage, IDisableEncryptionStorage,
 		return $permissions;
 	}
 
-	public function free_space($path) {
+	public function free_space($path): int|float|false {
 		return parent::free_space('');
 	}
 
diff --git a/apps/files_sharing/lib/SharedStorage.php b/apps/files_sharing/lib/SharedStorage.php
index 0a6a068c441..7addc9f0a91 100644
--- a/apps/files_sharing/lib/SharedStorage.php
+++ b/apps/files_sharing/lib/SharedStorage.php
@@ -9,18 +9,21 @@ namespace OCA\Files_Sharing;
 use OC\Files\Cache\CacheDependencies;
 use OC\Files\Cache\FailedCache;
 use OC\Files\Cache\NullWatcher;
-use OC\Files\Cache\Watcher;
 use OC\Files\ObjectStore\HomeObjectStoreStorage;
 use OC\Files\Storage\Common;
 use OC\Files\Storage\FailedStorage;
 use OC\Files\Storage\Home;
+use OC\Files\Storage\Storage;
 use OC\Files\Storage\Wrapper\PermissionsMask;
 use OC\Files\Storage\Wrapper\Wrapper;
 use OC\User\NoUserException;
 use OCA\Files_External\Config\ConfigAdapter;
 use OCA\Files_Sharing\ISharedStorage as LegacyISharedStorage;
 use OCP\Constants;
+use OCP\Files\Cache\ICache;
 use OCP\Files\Cache\ICacheEntry;
+use OCP\Files\Cache\IScanner;
+use OCP\Files\Cache\IWatcher;
 use OCP\Files\Config\IUserMountCache;
 use OCP\Files\Folder;
 use OCP\Files\IHomeStorage;
@@ -78,7 +81,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 
 	/**
 	 * @psalm-suppress NonInvariantDocblockPropertyType
-	 * @var ?\OC\Files\Storage\Storage $storage
+	 * @var ?Storage $storage
 	 */
 	protected $storage;
 
@@ -118,7 +121,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 	}
 
 	/**
-	 * @psalm-assert \OC\Files\Storage\Storage $this->storage
+	 * @psalm-assert Storage $this->storage
 	 */
 	private function init() {
 		if ($this->initialized) {
@@ -199,9 +202,6 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		self::$initDepth--;
 	}
 
-	/**
-	 * @inheritdoc
-	 */
 	public function instanceOfStorage($class): bool {
 		if ($class === '\OC\Files\Storage\Common' || $class == Common::class) {
 			return true;
@@ -230,21 +230,10 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		return $this->getSourceRootInfo() && ($this->getSourceRootInfo()->getPermissions() & Constants::PERMISSION_SHARE) === Constants::PERMISSION_SHARE;
 	}
 
-	/**
-	 * get id of the mount point
-	 *
-	 * @return string
-	 */
 	public function getId(): string {
 		return 'shared::' . $this->getMountPoint();
 	}
 
-	/**
-	 * Get the permissions granted for a shared file
-	 *
-	 * @param string $path Shared target file path
-	 * @return int CRUDS permissions granted
-	 */
 	public function getPermissions($path = ''): int {
 		if (!$this->isValid()) {
 			return 0;
@@ -347,13 +336,6 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		return $this->nonMaskedStorage->fopen($this->getUnjailedPath($path), $mode);
 	}
 
-	/**
-	 * see https://www.php.net/manual/en/function.rename.php
-	 *
-	 * @param string $source
-	 * @param string $target
-	 * @return bool
-	 */
 	public function rename($source, $target): bool {
 		$this->init();
 		$isPartFile = pathinfo($source, PATHINFO_EXTENSION) === 'part';
@@ -402,9 +384,6 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		return $this->superShare->getShareOwner();
 	}
 
-	/**
-	 * @return \OCP\Share\IShare
-	 */
 	public function getShare(): IShare {
 		return $this->superShare;
 	}
@@ -418,7 +397,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		return $this->superShare->getNodeType();
 	}
 
-	public function getCache($path = '', $storage = null) {
+	public function getCache($path = '', $storage = null): ICache {
 		if ($this->cache) {
 			return $this->cache;
 		}
@@ -439,7 +418,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		return $this->cache;
 	}
 
-	public function getScanner($path = '', $storage = null) {
+	public function getScanner($path = '', $storage = null): IScanner {
 		if (!$storage) {
 			$storage = $this;
 		}
@@ -450,7 +429,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		return $this->superShare->getShareOwner();
 	}
 
-	public function getWatcher($path = '', $storage = null): Watcher {
+	public function getWatcher($path = '', $storage = null): IWatcher {
 		if ($this->watcher) {
 			return $this->watcher;
 		}
@@ -488,7 +467,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		return true;
 	}
 
-	public function acquireLock($path, $type, ILockingProvider $provider) {
+	public function acquireLock($path, $type, ILockingProvider $provider): void {
 		/** @var ILockingStorage $targetStorage */
 		[$targetStorage, $targetInternalPath] = $this->resolvePath($path);
 		$targetStorage->acquireLock($targetInternalPath, $type, $provider);
@@ -499,7 +478,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		}
 	}
 
-	public function releaseLock($path, $type, ILockingProvider $provider) {
+	public function releaseLock($path, $type, ILockingProvider $provider): void {
 		/** @var ILockingStorage $targetStorage */
 		[$targetStorage, $targetInternalPath] = $this->resolvePath($path);
 		$targetStorage->releaseLock($targetInternalPath, $type, $provider);
@@ -510,16 +489,13 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		}
 	}
 
-	public function changeLock($path, $type, ILockingProvider $provider) {
+	public function changeLock($path, $type, ILockingProvider $provider): void {
 		/** @var ILockingStorage $targetStorage */
 		[$targetStorage, $targetInternalPath] = $this->resolvePath($path);
 		$targetStorage->changeLock($targetInternalPath, $type, $provider);
 	}
 
-	/**
-	 * @return array [ available, last_checked ]
-	 */
-	public function getAvailability() {
+	public function getAvailability(): array {
 		// shares do not participate in availability logic
 		return [
 			'available' => true,
@@ -527,10 +503,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		];
 	}
 
-	/**
-	 * @param bool $isAvailable
-	 */
-	public function setAvailability($isAvailable) {
+	public function setAvailability($isAvailable): void {
 		// shares do not participate in availability logic
 	}
 
@@ -539,7 +512,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		return $this->nonMaskedStorage;
 	}
 
-	public function getWrapperStorage() {
+	public function getWrapperStorage(): Storage {
 		$this->init();
 
 		/**
@@ -554,7 +527,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		return $this->storage;
 	}
 
-	public function file_get_contents($path) {
+	public function file_get_contents($path): string|false {
 		$info = [
 			'target' => $this->getMountPoint() . '/' . $path,
 			'source' => $this->getUnjailedPath($path),
@@ -563,7 +536,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		return parent::file_get_contents($path);
 	}
 
-	public function file_put_contents($path, $data) {
+	public function file_put_contents($path, $data): int|float|false {
 		$info = [
 			'target' => $this->getMountPoint() . '/' . $path,
 			'source' => $this->getUnjailedPath($path),
@@ -580,7 +553,7 @@ class SharedStorage extends \OC\Files\Storage\Wrapper\Jail implements LegacyISha
 		$this->mountOptions = $options;
 	}
 
-	public function getUnjailedPath($path) {
+	public function getUnjailedPath($path): string {
 		$this->init();
 		return parent::getUnjailedPath($path);
 	}
diff --git a/apps/files_sharing/tests/ExternalStorageTest.php b/apps/files_sharing/tests/ExternalStorageTest.php
index 56a1f320030..90aad4dca6e 100644
--- a/apps/files_sharing/tests/ExternalStorageTest.php
+++ b/apps/files_sharing/tests/ExternalStorageTest.php
@@ -95,7 +95,8 @@ class ExternalStorageTest extends \Test\TestCase {
 	}
 
 	public function testIfTestReturnsTheValue(): void {
-		$result = $this->getTestStorage('https://remoteserver')->test();
+		$storage = $this->getTestStorage('https://remoteserver');
+		$result = $storage->test();
 		$this->assertSame(true, $result);
 	}
 }
@@ -108,9 +109,9 @@ class TestSharingExternalStorage extends \OCA\Files_Sharing\External\Storage {
 		return $this->createBaseUri();
 	}
 
-	public function stat($path) {
+	public function stat($path): array|false {
 		if ($path === '') {
-			return true;
+			return ['key' => 'value'];
 		}
 		return parent::stat($path);
 	}
diff --git a/apps/files_trashbin/lib/Storage.php b/apps/files_trashbin/lib/Storage.php
index c05d248c9d0..23a0e5bd919 100644
--- a/apps/files_trashbin/lib/Storage.php
+++ b/apps/files_trashbin/lib/Storage.php
@@ -48,14 +48,7 @@ class Storage extends Wrapper {
 		parent::__construct($parameters);
 	}
 
-	/**
-	 * Deletes the given file by moving it into the trashbin.
-	 *
-	 * @param string $path path of file or folder to delete
-	 *
-	 * @return bool true if the operation succeeded, false otherwise
-	 */
-	public function unlink($path) {
+	public function unlink($path): bool {
 		if ($this->trashEnabled) {
 			try {
 				return $this->doDelete($path, 'unlink');
@@ -72,14 +65,7 @@ class Storage extends Wrapper {
 		}
 	}
 
-	/**
-	 * Deletes the given folder by moving it into the trashbin.
-	 *
-	 * @param string $path path of folder to delete
-	 *
-	 * @return bool true if the operation succeeded, false otherwise
-	 */
-	public function rmdir($path) {
+	public function rmdir($path): bool {
 		if ($this->trashEnabled) {
 			return $this->doDelete($path, 'rmdir');
 		} else {
@@ -94,7 +80,7 @@ class Storage extends Wrapper {
 	 * @param $path
 	 * @return bool
 	 */
-	protected function shouldMoveToTrash($path) {
+	protected function shouldMoveToTrash($path): bool {
 		$normalized = Filesystem::normalizePath($this->mountPoint . '/' . $path);
 		$parts = explode('/', $normalized);
 		if (count($parts) < 4 || strpos($normalized, '/appdata_') === 0) {
@@ -132,7 +118,7 @@ class Storage extends Wrapper {
 	 * @param Node $node
 	 * @return MoveToTrashEvent
 	 */
-	protected function createMoveToTrashEvent(Node $node) {
+	protected function createMoveToTrashEvent(Node $node): MoveToTrashEvent {
 		return new MoveToTrashEvent($node);
 	}
 
@@ -144,7 +130,7 @@ class Storage extends Wrapper {
 	 *
 	 * @return bool true if the operation succeeded, false otherwise
 	 */
-	private function doDelete($path, $method) {
+	private function doDelete($path, $method): bool {
 		if (
 			!\OC::$server->getAppManager()->isEnabledForUser('files_trashbin')
 			|| (pathinfo($path, PATHINFO_EXTENSION) === 'part')
@@ -170,7 +156,7 @@ class Storage extends Wrapper {
 	/**
 	 * Setup the storage wrapper callback
 	 */
-	public static function setupStorage() {
+	public static function setupStorage(): void {
 		$trashManager = \OC::$server->get(ITrashManager::class);
 		$userManager = \OC::$server->get(IUserManager::class);
 		$logger = \OC::$server->get(LoggerInterface::class);
@@ -195,7 +181,7 @@ class Storage extends Wrapper {
 		return $this->mountPoint;
 	}
 
-	public function moveFromStorage(IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath) {
+	public function moveFromStorage(IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath): bool {
 		$sourceIsTrashbin = $sourceStorage->instanceOfStorage(Storage::class);
 		try {
 			// the fallback for moving between storage involves a copy+delete
@@ -219,11 +205,11 @@ class Storage extends Wrapper {
 		}
 	}
 
-	protected function disableTrash() {
+	protected function disableTrash(): void {
 		$this->trashEnabled = false;
 	}
 
-	protected function enableTrash() {
+	protected function enableTrash(): void {
 		$this->trashEnabled = true;
 	}
 }
diff --git a/apps/files_trashbin/tests/StorageTest.php b/apps/files_trashbin/tests/StorageTest.php
index f0f3159b32a..9de4bf0cc13 100644
--- a/apps/files_trashbin/tests/StorageTest.php
+++ b/apps/files_trashbin/tests/StorageTest.php
@@ -29,11 +29,11 @@ use Psr\Log\LoggerInterface;
 use Test\Traits\MountProviderTrait;
 
 class TemporaryNoCross extends Temporary {
-	public function copyFromStorage(IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime = null) {
+	public function copyFromStorage(IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime = null): bool {
 		return Common::copyFromStorage($sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime);
 	}
 
-	public function moveFromStorage(IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath) {
+	public function moveFromStorage(IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath): bool {
 		return Common::moveFromStorage($sourceStorage, $sourceInternalPath, $targetInternalPath);
 	}
 }
diff --git a/apps/workflowengine/tests/Check/FileMimeTypeTest.php b/apps/workflowengine/tests/Check/FileMimeTypeTest.php
index 1fc5118c5c4..0911a47f894 100644
--- a/apps/workflowengine/tests/Check/FileMimeTypeTest.php
+++ b/apps/workflowengine/tests/Check/FileMimeTypeTest.php
@@ -16,7 +16,7 @@ use OCP\IRequest;
 use Test\TestCase;
 
 class TemporaryNoLocal extends Temporary {
-	public function instanceOfStorage($className) {
+	public function instanceOfStorage($className): bool {
 		if ($className === '\OC\Files\Storage\Local') {
 			return false;
 		} else {