diff --git a/classes/Config.php b/classes/Config.php
index 88fc0cc..c68d5b3 100644
--- a/classes/Config.php
+++ b/classes/Config.php
@@ -40,7 +40,7 @@ class Config
     /**
      * youtube-dl parameters.
      *
-     * @var array
+     * @var string[]
      */
     public $params = ['--no-warnings', '--ignore-errors', '--flat-playlist', '--restrict-filenames', '--no-playlist'];
 
@@ -61,7 +61,7 @@ class Config
     /**
      * List of formats available in advanced conversion mode.
      *
-     * @var array
+     * @var string[]
      */
     public $convertAdvancedFormats = ['mp3', 'avi', 'flv', 'wav'];
 
@@ -125,7 +125,7 @@ class Config
     /**
      * Generic formats supported by youtube-dl.
      *
-     * @var array
+     * @var string[]
      */
     public $genericFormats = [];
 
@@ -139,7 +139,8 @@ class Config
     /**
      * Config constructor.
      *
-     * @param array $options Options
+     * @param mixed[] $options Options
+     * @throws CaseConverterException
      */
     private function __construct(array $options = [])
     {
@@ -210,7 +211,7 @@ class Config
     /**
      * Apply the provided options.
      *
-     * @param array $options Options
+     * @param mixed[] $options Options
      *
      * @return void
      */
@@ -260,12 +261,13 @@ class Config
      * Set options from a YAML file.
      *
      * @param string $file Path to the YAML file
+     * @return void
      * @throws Exception
      */
     public static function setFile($file)
     {
         if (is_file($file)) {
-            $options = Yaml::parse(file_get_contents($file));
+            $options = Yaml::parse(strval(file_get_contents($file)));
             self::$instance = new self($options);
             self::$instance->validateOptions();
         } else {
@@ -276,8 +278,9 @@ class Config
     /**
      * Manually set some options.
      *
-     * @param array $options Options (see `config/config.example.yml` for available options)
+     * @param mixed[] $options Options (see `config/config.example.yml` for available options)
      * @param bool $update True to update an existing instance
+     * @return void
      * @throws Exception
      */
     public static function setOptions(array $options, $update = true)
diff --git a/classes/Locale.php b/classes/Locale.php
index 2d27721..f8ebf2f 100644
--- a/classes/Locale.php
+++ b/classes/Locale.php
@@ -104,7 +104,7 @@ class Locale
     /**
      * Get country information from locale.
      *
-     * @return Country|array|null
+     * @return Country|Country[]|null
      */
     public function getCountry()
     {
diff --git a/classes/LocaleManager.php b/classes/LocaleManager.php
index 12c14dd..813ea79 100644
--- a/classes/LocaleManager.php
+++ b/classes/LocaleManager.php
@@ -18,7 +18,7 @@ class LocaleManager
     /**
      * Supported locales.
      *
-     * @var array
+     * @var string[]
      */
     private $supportedLocales = ['en_US', 'fr_FR', 'zh_CN', 'es_ES', 'pt_BR', 'de_DE', 'ar', 'pl_PL', 'tr_TR'];
 
@@ -111,6 +111,7 @@ class LocaleManager
      * Set the current locale.
      *
      * @param Locale $locale Locale
+     * @return void
      */
     public function setLocale(Locale $locale)
     {
@@ -121,6 +122,7 @@ class LocaleManager
 
     /**
      * Unset the current locale.
+     * @return void
      */
     public function unsetLocale()
     {
@@ -132,8 +134,8 @@ class LocaleManager
     /**
      * Smarty "t" block.
      *
-     * @param  array  $params Block parameters
-     * @param  string $text  Block content
+     * @param mixed[] $params Block parameters
+     * @param string $text Block content
      *
      * @return string Translated string
      */
@@ -151,6 +153,7 @@ class LocaleManager
      *
      * @param string $string String to translate
      *
+     * @param mixed[] $params
      * @return string Translated string
      */
     public function t($string, array $params = [])
diff --git a/classes/LocaleMiddleware.php b/classes/LocaleMiddleware.php
index 5d0aac5..b7395bd 100644
--- a/classes/LocaleMiddleware.php
+++ b/classes/LocaleMiddleware.php
@@ -36,7 +36,7 @@ class LocaleMiddleware
     /**
      * Test if a locale can be used for the current user.
      *
-     * @param array $proposedLocale Locale array created by AcceptLanguage::parse()
+     * @param mixed[] $proposedLocale Locale array created by AcceptLanguage::parse()
      *
      * @return Locale|null Locale if chosen, nothing otherwise
      */
@@ -59,9 +59,9 @@ class LocaleMiddleware
     /**
      * Main middleware function.
      *
-     * @param Request  $request  PSR request
+     * @param Request $request PSR request
      * @param Response $response PSR response
-     * @param callable $next     Next middleware
+     * @param callable $next Next middleware
      *
      * @return Response
      */
diff --git a/classes/UglyRouter.php b/classes/UglyRouter.php
index 89ec2bb..f03efe7 100644
--- a/classes/UglyRouter.php
+++ b/classes/UglyRouter.php
@@ -21,7 +21,7 @@ class UglyRouter extends Router
      *
      * @param ServerRequestInterface $request The current HTTP request object
      *
-     * @return array
+     * @return mixed[]
      *
      * @link   https://github.com/nikic/FastRoute/blob/master/src/Dispatcher.php
      */
@@ -42,14 +42,14 @@ class UglyRouter extends Router
     /**
      * Build the path for a named route including the base path.
      *
-     * @param string $name        Route name
-     * @param array  $data        Named argument replacement data
-     * @param array  $queryParams Optional query string parameters
-     *
-     * @throws RuntimeException         If named route does not exist
-     * @throws InvalidArgumentException If required data not provided
+     * @param string $name Route name
+     * @param string[] $data Named argument replacement data
+     * @param string[] $queryParams Optional query string parameters
      *
      * @return string
+     * @throws InvalidArgumentException If required data not provided
+     *
+     * @throws RuntimeException         If named route does not exist
      */
     public function pathFor($name, array $data = [], array $queryParams = [])
     {
diff --git a/classes/Video.php b/classes/Video.php
index cfea97d..8b67ae0 100644
--- a/classes/Video.php
+++ b/classes/Video.php
@@ -19,16 +19,16 @@ use Symfony\Component\Process\Process;
  *
  * Due to the way youtube-dl behaves, this class can also contain information about a playlist.
  *
- * @property-read string      $title         Title
- * @property-read string      $protocol      Network protocol (HTTP, RTMP, etc.)
- * @property-read string      $url           File URL
- * @property-read string      $ext           File extension
- * @property-read string      $extractor_key youtube-dl extractor class used
- * @property-read array       $entries       List of videos (if the object contains information about a playlist)
- * @property-read array       $rtmp_conn
+ * @property-read string $title         Title
+ * @property-read string $protocol      Network protocol (HTTP, RTMP, etc.)
+ * @property-read string $url           File URL
+ * @property-read string $ext           File extension
+ * @property-read string $extractor_key youtube-dl extractor class used
+ * @property-read array $entries       List of videos (if the object contains information about a playlist)
+ * @property-read array $rtmp_conn
  * @property-read string|null $_type         Object type (usually "playlist" or null)
- * @property-read stdClass    $downloader_options
- * @property-read stdClass    $http_headers
+ * @property-read stdClass $downloader_options
+ * @property-read stdClass $http_headers
  */
 class Video
 {
@@ -70,7 +70,7 @@ class Video
     /**
      * URLs of the video files.
      *
-     * @var array
+     * @var string[]
      */
     private $urls;
 
@@ -84,11 +84,11 @@ class Video
     /**
      * VideoDownload constructor.
      *
-     * @param string $webpageUrl      URL of the page containing the video
+     * @param string $webpageUrl URL of the page containing the video
      * @param string $requestedFormat Requested video format
      *                                (can be any format string accepted by youtube-dl,
      *                                including selectors like "[height<=720]")
-     * @param string $password        Password
+     * @param string $password Password
      */
     public function __construct($webpageUrl, $requestedFormat = 'best', $password = null)
     {
@@ -105,7 +105,7 @@ class Video
      *
      * @param string[] $arguments Arguments
      *
-     * @return Process
+     * @return Process<string>
      */
     private static function getProcess(array $arguments)
     {
@@ -137,13 +137,13 @@ class Video
     /**
      * Call youtube-dl.
      *
-     * @param array $arguments Arguments
+     * @param string[] $arguments Arguments
      *
-     * @throws PasswordException If the video is protected by a password and no password was specified
+     * @return string Result
      * @throws Exception         If the password is wrong
      * @throws Exception         If youtube-dl returns an error
      *
-     * @return string Result
+     * @throws PasswordException If the video is protected by a password and no password was specified
      */
     private function callYoutubedl(array $arguments)
     {
@@ -155,7 +155,7 @@ class Video
         $process->run();
         if (!$process->isSuccessful()) {
             $errorOutput = trim($process->getErrorOutput());
-            $exitCode = $process->getExitCode();
+            $exitCode = intval($process->getExitCode());
             if ($errorOutput == 'ERROR: This video is protected by a password, use the --video-password option') {
                 throw new PasswordException($errorOutput, $exitCode);
             } elseif (substr($errorOutput, 0, 21) == 'ERROR: Wrong password') {
@@ -294,7 +294,7 @@ class Video
     /**
      * Return arguments used to run rtmp for a specific video.
      *
-     * @return array Arguments
+     * @return string[] Arguments
      */
     private function getRtmpArguments()
     {
@@ -303,12 +303,12 @@ class Video
         if ($this->protocol == 'rtmp') {
             foreach (
                 [
-                'url'           => '-rtmp_tcurl',
-                'webpage_url'   => '-rtmp_pageurl',
-                'player_url'    => '-rtmp_swfverify',
-                'flash_version' => '-rtmp_flashver',
-                'play_path'     => '-rtmp_playpath',
-                'app'           => '-rtmp_app',
+                    'url' => '-rtmp_tcurl',
+                    'webpage_url' => '-rtmp_pageurl',
+                    'player_url' => '-rtmp_swfverify',
+                    'flash_version' => '-rtmp_flashver',
+                    'play_path' => '-rtmp_playpath',
+                    'app' => '-rtmp_app',
                 ] as $property => $option
             ) {
                 if (isset($this->{$property})) {
@@ -331,7 +331,7 @@ class Video
     /**
      * Check if a command runs successfully.
      *
-     * @param array $command Command and arguments
+     * @param string[] $command Command and arguments
      *
      * @return bool False if the command returns an error, true otherwise
      */
@@ -346,15 +346,15 @@ class Video
     /**
      * Get a process that runs avconv in order to convert a video.
      *
-     * @param int    $audioBitrate Audio bitrate of the converted file
-     * @param string $filetype     Filetype of the converted file
-     * @param bool   $audioOnly    True to return an audio-only file
-     * @param string $from         Start the conversion at this time
-     * @param string $to           End the conversion at this time
+     * @param int $audioBitrate Audio bitrate of the converted file
+     * @param string $filetype Filetype of the converted file
+     * @param bool $audioOnly True to return an audio-only file
+     * @param string $from Start the conversion at this time
+     * @param string $to End the conversion at this time
      *
+     * @return Process<string> Process
      * @throws Exception If avconv/ffmpeg is missing
      *
-     * @return Process Process
      */
     private function getAvconvProcess(
         $audioBitrate,
@@ -425,12 +425,12 @@ class Video
      * Get audio stream of converted video.
      *
      * @param string $from Start the conversion at this time
-     * @param string $to   End the conversion at this time
-     *
-     * @throws Exception If your try to convert an M3U8 video
-     * @throws Exception If the popen stream was not created correctly
+     * @param string $to End the conversion at this time
      *
      * @return resource popen stream
+     * @throws Exception If the popen stream was not created correctly
+     *
+     * @throws Exception If your try to convert an M3U8 video
      */
     public function getAudioStream($from = null, $to = null)
     {
@@ -460,10 +460,10 @@ class Video
     /**
      * Get video stream from an M3U playlist.
      *
-     * @throws Exception If avconv/ffmpeg is missing
+     * @return resource popen stream
      * @throws Exception If the popen stream was not created correctly
      *
-     * @return resource popen stream
+     * @throws Exception If avconv/ffmpeg is missing
      */
     public function getM3uStream()
     {
@@ -502,9 +502,9 @@ class Video
     /**
      * Get an avconv stream to remux audio and video.
      *
+     * @return resource popen stream
      * @throws Exception If the popen stream was not created correctly
      *
-     * @return resource popen stream
      */
     public function getRemuxStream()
     {
@@ -539,9 +539,9 @@ class Video
     /**
      * Get video stream from an RTMP video.
      *
+     * @return resource popen stream
      * @throws Exception If the popen stream was not created correctly
      *
-     * @return resource popen stream
      */
     public function getRtmpStream()
     {
@@ -572,13 +572,13 @@ class Video
     /**
      * Get the stream of a converted video.
      *
-     * @param int    $audioBitrate Audio bitrate of the converted file
-     * @param string $filetype     Filetype of the converted file
-     *
-     * @throws Exception If your try to convert and M3U8 video
-     * @throws Exception If the popen stream was not created correctly
+     * @param int $audioBitrate Audio bitrate of the converted file
+     * @param string $filetype Filetype of the converted file
      *
      * @return resource popen stream
+     * @throws Exception If the popen stream was not created correctly
+     *
+     * @throws Exception If your try to convert and M3U8 video
      */
     public function getConvertedStream($audioBitrate, $filetype)
     {
@@ -612,7 +612,7 @@ class Video
     /**
      * Get a HTTP response containing the video.
      *
-     * @param array $headers HTTP headers of the request
+     * @param mixed[] $headers HTTP headers of the request
      *
      * @return ResponseInterface
      * @throws EmptyUrlException
@@ -628,7 +628,7 @@ class Video
             $urls[0],
             [
                 'stream' => true,
-                'headers' => array_merge((array) $this->http_headers, $headers)
+                'headers' => array_merge((array)$this->http_headers, $headers)
             ]
         );
     }
diff --git a/classes/ViewFactory.php b/classes/ViewFactory.php
index 89e52ec..e5c0bb7 100644
--- a/classes/ViewFactory.php
+++ b/classes/ViewFactory.php
@@ -29,7 +29,7 @@ class ViewFactory
     public static function create(ContainerInterface $container, Request $request = null)
     {
         if (!isset($request)) {
-            $request = $container['request'];
+            $request = $container->get('request');
         }
 
         $view = new Smarty(__DIR__ . '/../templates/');
@@ -37,9 +37,10 @@ class ViewFactory
             $request = $request->withUri($request->getUri()->withScheme('https')->withPort(443));
         }
 
-        $localeManager = $container['locale'];
+        /** @var LocaleManager $localeManager */
+        $localeManager = $container->get('locale');
 
-        $smartyPlugins = new SmartyPlugins($container['router'], $request->getUri()->withUserInfo(null));
+        $smartyPlugins = new SmartyPlugins($container->get('router'), $request->getUri()->withUserInfo(null));
         $view->registerPlugin('function', 'path_for', [$smartyPlugins, 'pathFor']);
         $view->registerPlugin('function', 'base_url', [$smartyPlugins, 'baseUrl']);
         $view->registerPlugin('block', 't', [$localeManager, 'smartyTranslate']);
diff --git a/classes/streams/PlaylistArchiveStream.php b/classes/streams/PlaylistArchiveStream.php
index 8fe4878..9792cef 100644
--- a/classes/streams/PlaylistArchiveStream.php
+++ b/classes/streams/PlaylistArchiveStream.php
@@ -6,6 +6,8 @@
 
 namespace Alltube\Stream;
 
+use Alltube\Exception\EmptyUrlException;
+use Alltube\Exception\PasswordException;
 use Alltube\Video;
 use Barracuda\ArchiveStream\ZipArchive;
 use Psr\Http\Message\StreamInterface;
@@ -86,20 +88,21 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
      *
      * @param string $string The string that is to be written
      *
-     * @return void
+     * @return int|false
      */
     public function write($string)
     {
-        fwrite($this->buffer, $string);
+        return fwrite($this->buffer, $string);
     }
 
     /**
      * Get the size of the stream if known.
      *
-     * @return void
+     * @return int|null
      */
     public function getSize()
     {
+        return null;
     }
 
     /**
@@ -145,7 +148,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
     /**
      * Returns the remaining contents in a string.
      *
-     * @return string
+     * @return string|false
      */
     public function getContents()
     {
@@ -196,7 +199,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
     {
         $this->rewind();
 
-        return $this->getContents();
+        return strval($this->getContents());
     }
 
     /**
@@ -238,6 +241,8 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
      * @param Video $video Video to stream
      *
      * @return void
+     * @throws PasswordException
+     * @throws EmptyUrlException
      */
     protected function startVideoStream(Video $video)
     {
@@ -248,7 +253,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
 
         $this->init_file_stream_transfer(
             $video->getFilename(),
-            $contentLengthHeaders[0]
+            intval($contentLengthHeaders[0])
         );
     }
 
diff --git a/classes/streams/YoutubeChunkStream.php b/classes/streams/YoutubeChunkStream.php
index 91ee219..c99f422 100644
--- a/classes/streams/YoutubeChunkStream.php
+++ b/classes/streams/YoutubeChunkStream.php
@@ -41,7 +41,7 @@ class YoutubeChunkStream implements StreamInterface
      */
     public function read($length)
     {
-        $size = $this->response->getHeader('Content-Length')[0];
+        $size = intval($this->response->getHeader('Content-Length')[0]);
         if ($size - $this->tell() < $length) {
             // Don't try to read further than the end of the stream.
             $length = $size - $this->tell();
@@ -55,7 +55,7 @@ class YoutubeChunkStream implements StreamInterface
      */
     public function __toString()
     {
-        return (string) $this->response->getBody();
+        return (string)$this->response->getBody();
     }
 
     /**
diff --git a/classes/streams/YoutubeStream.php b/classes/streams/YoutubeStream.php
index a3e9ac1..3995d11 100644
--- a/classes/streams/YoutubeStream.php
+++ b/classes/streams/YoutubeStream.php
@@ -6,6 +6,8 @@
 
 namespace Alltube\Stream;
 
+use Alltube\Exception\EmptyUrlException;
+use Alltube\Exception\PasswordException;
 use Alltube\Video;
 use GuzzleHttp\Psr7\AppendStream;
 
@@ -19,6 +21,8 @@ class YoutubeStream extends AppendStream
      * YoutubeStream constructor.
      *
      * @param Video $video Video to stream
+     * @throws EmptyUrlException
+     * @throws PasswordException
      */
     public function __construct(Video $video)
     {
@@ -31,7 +35,7 @@ class YoutubeStream extends AppendStream
         while ($rangeStart < $contentLenghtHeader[0]) {
             $rangeEnd = $rangeStart + $video->downloader_options->http_chunk_size;
             if ($rangeEnd >= $contentLenghtHeader[0]) {
-                $rangeEnd = $contentLenghtHeader[0] - 1;
+                $rangeEnd = intval($contentLenghtHeader[0]) - 1;
             }
             $response = $video->getHttpResponse(['Range' => 'bytes=' . $rangeStart . '-' . $rangeEnd]);
             $this->addStream(new YoutubeChunkStream($response));
diff --git a/composer.json b/composer.json
index adcf9da..11b457a 100644
--- a/composer.json
+++ b/composer.json
@@ -27,7 +27,7 @@
     "heroku/heroku-buildpack-php": "^162.0",
     "php-mock/php-mock-mockery": "^1.3",
     "phpro/grumphp": "^0.17.0",
-    "phpstan/phpstan": "~0.9.2",
+    "phpstan/phpstan": "^0.12.25",
     "phpunit/phpunit": "^8.4",
     "roave/security-advisories": "dev-master",
     "smarty-gettext/smarty-gettext": "^1.6",
diff --git a/composer.lock b/composer.lock
index 12f6d4a..aa9c02a 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "d6b6d55bcc8f884443734ed9e2b3d94f",
+    "content-hash": "1b8bd0ca72e9fbff0c51280a0c2c3e91",
     "packages": [
         {
             "name": "aura/session",
@@ -3820,66 +3820,45 @@
         },
         {
             "name": "phpstan/phpstan",
-            "version": "0.9.2",
+            "version": "0.12.25",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpstan/phpstan.git",
-                "reference": "e59541bcc7cac9b35ca54db6365bf377baf4a488"
+                "reference": "9619551d68b2d4c0d681a8df73f3c847c798ee64"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/e59541bcc7cac9b35ca54db6365bf377baf4a488",
-                "reference": "e59541bcc7cac9b35ca54db6365bf377baf4a488",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/9619551d68b2d4c0d681a8df73f3c847c798ee64",
+                "reference": "9619551d68b2d4c0d681a8df73f3c847c798ee64",
                 "shasum": ""
             },
             "require": {
-                "jean85/pretty-package-versions": "^1.0.3",
-                "nette/bootstrap": "^2.4 || ^3.0",
-                "nette/di": "^2.4.7 || ^3.0",
-                "nette/robot-loader": "^3.0.1",
-                "nette/utils": "^2.4.5 || ^3.0",
-                "nikic/php-parser": "^3.1",
-                "php": "~7.0",
-                "phpstan/phpdoc-parser": "^0.2",
-                "symfony/console": "~3.2 || ~4.0",
-                "symfony/finder": "~3.2 || ~4.0"
+                "php": "^7.1"
             },
-            "require-dev": {
-                "consistence/coding-standard": "2.2.1",
-                "ext-gd": "*",
-                "ext-intl": "*",
-                "ext-mysqli": "*",
-                "jakub-onderka/php-parallel-lint": "^0.9.2",
-                "phing/phing": "^2.16.0",
-                "phpstan/phpstan-php-parser": "^0.9",
-                "phpstan/phpstan-phpunit": "^0.9.3",
-                "phpstan/phpstan-strict-rules": "^0.9",
-                "phpunit/phpunit": "^6.5.4",
-                "slevomat/coding-standard": "4.0.0"
+            "conflict": {
+                "phpstan/phpstan-shim": "*"
             },
             "bin": [
-                "bin/phpstan"
+                "phpstan",
+                "phpstan.phar"
             ],
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "0.9-dev"
+                    "dev-master": "0.12-dev"
                 }
             },
             "autoload": {
-                "psr-4": {
-                    "PHPStan\\": [
-                        "src/",
-                        "build/PHPStan"
-                    ]
-                }
+                "files": [
+                    "bootstrap.php"
+                ]
             },
             "notification-url": "https://packagist.org/downloads/",
             "license": [
                 "MIT"
             ],
             "description": "PHPStan - PHP Static Analysis Tool",
-            "time": "2018-01-28T13:22:19+00:00"
+            "time": "2020-05-10T20:36:16+00:00"
         },
         {
             "name": "phpunit/php-code-coverage",
diff --git a/controllers/FrontController.php b/controllers/FrontController.php
index e5f4536..0277cbc 100644
--- a/controllers/FrontController.php
+++ b/controllers/FrontController.php
@@ -45,7 +45,7 @@ class FrontController extends BaseController
     /**
      * Display index page.
      *
-     * @param Request  $request  PSR-7 request
+     * @param Request $request PSR-7 request
      * @param Response $response PSR-7 response
      *
      * @return Response HTTP response
@@ -57,15 +57,15 @@ class FrontController extends BaseController
             $response,
             'index.tpl',
             [
-                'config'           => $this->config,
-                'class'            => 'index',
-                'description'      => $this->localeManager->t(
+                'config' => $this->config,
+                'class' => 'index',
+                'description' => $this->localeManager->t(
                     'Easily download videos from Youtube, Dailymotion, Vimeo and other websites.'
                 ),
-                'domain'           => $uri->getScheme() . '://' . $uri->getAuthority(),
-                'canonical'        => $this->getCanonicalUrl($request),
+                'domain' => $uri->getScheme() . '://' . $uri->getAuthority(),
+                'canonical' => $this->getCanonicalUrl($request),
                 'supportedLocales' => $this->localeManager->getSupportedLocales(),
-                'locale'           => $this->localeManager->getLocale(),
+                'locale' => $this->localeManager->getLocale(),
             ]
         );
 
@@ -75,9 +75,9 @@ class FrontController extends BaseController
     /**
      * Switch locale.
      *
-     * @param Request  $request  PSR-7 request
+     * @param Request $request PSR-7 request
      * @param Response $response PSR-7 response
-     * @param array    $data     Query parameters
+     * @param string[] $data Query parameters
      *
      * @return Response
      */
@@ -103,14 +103,14 @@ class FrontController extends BaseController
             $response,
             'extractors.tpl',
             [
-                'config'      => $this->config,
-                'extractors'  => Video::getExtractors(),
-                'class'       => 'extractors',
-                'title'       => $this->localeManager->t('Supported websites'),
+                'config' => $this->config,
+                'extractors' => Video::getExtractors(),
+                'class' => 'extractors',
+                'title' => $this->localeManager->t('Supported websites'),
                 'description' => $this->localeManager->t('List of all supported websites from which Alltube Download ' .
                     'can extract video or audio files'),
                 'canonical' => $this->getCanonicalUrl($request),
-                'locale'    => $this->localeManager->getLocale(),
+                'locale' => $this->localeManager->getLocale(),
             ]
         );
 
@@ -120,7 +120,7 @@ class FrontController extends BaseController
     /**
      * Display a password prompt.
      *
-     * @param Request  $request  PSR-7 request
+     * @param Request $request PSR-7 request
      * @param Response $response PSR-7 response
      *
      * @return Response HTTP response
@@ -131,14 +131,14 @@ class FrontController extends BaseController
             $response,
             'password.tpl',
             [
-                'config'      => $this->config,
-                'class'       => 'password',
-                'title'       => $this->localeManager->t('Password prompt'),
+                'config' => $this->config,
+                'class' => 'password',
+                'title' => $this->localeManager->t('Password prompt'),
                 'description' => $this->localeManager->t(
                     'You need a password in order to download this video with Alltube Download'
                 ),
-                'canonical'   => $this->getCanonicalUrl($request),
-                'locale'      => $this->localeManager->getLocale(),
+                'canonical' => $this->getCanonicalUrl($request),
+                'locale' => $this->localeManager->getLocale(),
             ]
         );
 
@@ -148,7 +148,7 @@ class FrontController extends BaseController
     /**
      * Return the video description page.
      *
-     * @param Request  $request  PSR-7 request
+     * @param Request $request PSR-7 request
      * @param Response $response PSR-7 response
      *
      * @return Response HTTP response
@@ -185,13 +185,13 @@ class FrontController extends BaseController
             $response,
             $template,
             [
-                'video'         => $this->video,
-                'class'         => 'info',
-                'title'         => $title,
-                'description'   => $description,
-                'config'        => $this->config,
-                'canonical'     => $this->getCanonicalUrl($request),
-                'locale'        => $this->localeManager->getLocale(),
+                'video' => $this->video,
+                'class' => 'info',
+                'title' => $title,
+                'description' => $description,
+                'config' => $this->config,
+                'canonical' => $this->getCanonicalUrl($request),
+                'locale' => $this->localeManager->getLocale(),
                 'defaultFormat' => $this->defaultFormat,
             ]
         );
@@ -202,7 +202,7 @@ class FrontController extends BaseController
     /**
      * Dislay information about the video.
      *
-     * @param Request  $request  PSR-7 request
+     * @param Request $request PSR-7 request
      * @param Response $response PSR-7 response
      *
      * @return Response HTTP response
@@ -231,9 +231,9 @@ class FrontController extends BaseController
     /**
      * Display an error page.
      *
-     * @param Request   $request   PSR-7 request
-     * @param Response  $response  PSR-7 response
-     * @param Throwable $error     Error to display
+     * @param Request $request PSR-7 request
+     * @param Response $response PSR-7 response
+     * @param Throwable $error Error to display
      *
      * @return Response HTTP response
      */
@@ -256,12 +256,12 @@ class FrontController extends BaseController
                 $response,
                 'error.tpl',
                 [
-                    'config'    => $this->config,
-                    'error'     => $message,
-                    'class'     => 'video',
-                    'title'     => $this->localeManager->t('Error'),
+                    'config' => $this->config,
+                    'error' => $message,
+                    'class' => 'video',
+                    'title' => $this->localeManager->t('Error'),
                     'canonical' => $this->getCanonicalUrl($request),
-                    'locale'    => $this->localeManager->getLocale(),
+                    'locale' => $this->localeManager->getLocale(),
                 ]
             );
 
diff --git a/index.php b/index.php
index 6dd0a45..0b7772c 100644
--- a/index.php
+++ b/index.php
@@ -10,6 +10,7 @@ use Alltube\LocaleMiddleware;
 use Alltube\UglyRouter;
 use Alltube\ViewFactory;
 use Slim\App;
+use Slim\Container;
 use Symfony\Component\Debug\Debug;
 
 if (isset($_SERVER['REQUEST_URI']) && strpos($_SERVER['REQUEST_URI'], '/index.php') !== false) {
@@ -23,6 +24,8 @@ if (is_file(__DIR__ . '/config/config.yml')) {
 
 // Create app.
 $app = new App();
+
+/** @var Container $container */
 $container = $app->getContainer();
 
 // Load config.
diff --git a/tests/ControllerTest.php b/tests/ControllerTest.php
index cea9f59..bd9f737 100644
--- a/tests/ControllerTest.php
+++ b/tests/ControllerTest.php
@@ -6,6 +6,7 @@
 
 namespace Alltube\Test;
 
+use Alltube\Controller\BaseController;
 use Alltube\Controller\DownloadController;
 use Alltube\Controller\FrontController;
 use Alltube\LocaleManager;
@@ -44,6 +45,7 @@ abstract class ControllerTest extends BaseTest
 
     /**
      * Controller instance used in tests.
+     * @var BaseController
      */
     protected $controller;
 
@@ -80,7 +82,7 @@ abstract class ControllerTest extends BaseTest
      * Run controller function with custom query parameters and return the result.
      *
      * @param string $request Controller function to call
-     * @param array  $params  Query parameters
+     * @param mixed[] $params Query parameters
      *
      * @return Response HTTP response
      */
@@ -96,7 +98,7 @@ abstract class ControllerTest extends BaseTest
      * Assert that calling controller function with these parameters returns a 200 HTTP response.
      *
      * @param string $request Controller function to call
-     * @param array  $params  Query parameters
+     * @param mixed[] $params Query parameters
      *
      * @return void
      */
@@ -109,7 +111,7 @@ abstract class ControllerTest extends BaseTest
      * Assert that calling controller function with these parameters returns an HTTP redirect.
      *
      * @param string $request Controller function to call
-     * @param array  $params  Query parameters
+     * @param mixed[] $params Query parameters
      *
      * @return void
      */
@@ -122,7 +124,7 @@ abstract class ControllerTest extends BaseTest
      * Assert that calling controller function with these parameters returns an HTTP 500 error.
      *
      * @param string $request Controller function to call
-     * @param array  $params  Query parameters
+     * @param mixed[] $params Query parameters
      *
      * @return void
      */
@@ -135,7 +137,7 @@ abstract class ControllerTest extends BaseTest
      * Assert that calling controller function with these parameters returns an HTTP 400 error.
      *
      * @param string $request Controller function to call
-     * @param array  $params  Query parameters
+     * @param mixed[] $params Query parameters
      *
      * @return void
      */
diff --git a/tests/FrontControllerTest.php b/tests/FrontControllerTest.php
index f75a457..92e4824 100644
--- a/tests/FrontControllerTest.php
+++ b/tests/FrontControllerTest.php
@@ -17,6 +17,12 @@ use Slim\Http\Request;
  */
 class FrontControllerTest extends ControllerTest
 {
+    /**
+     * Controller instance used in tests.
+     * @var FrontController
+     */
+    protected $controller;
+
     /**
      * Prepare tests.
      * @throws Exception
diff --git a/tests/StreamTest.php b/tests/StreamTest.php
index 7ffe235..bcd3887 100644
--- a/tests/StreamTest.php
+++ b/tests/StreamTest.php
@@ -6,6 +6,7 @@
 
 namespace Alltube\Test;
 
+use Psr\Http\Message\StreamInterface;
 use RuntimeException;
 
 /**
@@ -15,6 +16,7 @@ abstract class StreamTest extends BaseTest
 {
     /**
      * Stream instance.
+     * @var StreamInterface
      */
     protected $stream;