diff --git a/composer.json b/composer.json
index 227ca73e..6cf0763a 100644
--- a/composer.json
+++ b/composer.json
@@ -40,6 +40,8 @@
         "phpunit/phpunit": "^8",
         "amphp/php-cs-fixer-config": "dev-master",
         "haydenpierce/class-finder": "^0.4",
+        "amphp/websocket-client": "dev-master as 1",
+        "amphp/websocket": "dev-master as 1",
         "ext-ctype": "*",
         "danog/7to70": "^1",
         "danog/7to5": "^1"
@@ -62,6 +64,11 @@
             "src/polyfill.php"
         ]
     },
+    "autoload-dev": {
+        "psr-4": {
+            "danog\\MadelineProto\\Test\\": "tests/danog/"
+        }
+    },
     "repositories": [{
         "type": "git",
         "url": "https://github.com/danog/dns"
@@ -80,6 +87,6 @@
         "cs": "PHP_CS_FIXER_IGNORE_ENV=1 php-cs-fixer fix -v --diff --dry-run",
         "cs-fix": "PHP_CS_FIXER_IGNORE_ENV=1 php-cs-fixer fix -v --diff",
         "docs": "php tools/build_docs.php",
-        "test": "@php -dzend.assertions=1 -dassert.exception=1 ./vendor/bin/phpunit --coverage-text"
+        "test": "@php -dzend.assertions=1 -dassert.exception=1 ./vendor/bin/phpunit --coverage-text --config tests/phpunit.xml"
     }
 }
diff --git a/src/danog/MadelineProto/Connection.php b/src/danog/MadelineProto/Connection.php
index 5ec53e7e..1d73927e 100644
--- a/src/danog/MadelineProto/Connection.php
+++ b/src/danog/MadelineProto/Connection.php
@@ -466,7 +466,7 @@ class Connection extends Session
      *
      * @return void
      */
-    public function setExtra(DataCenterConnection $extra, int $id)
+    public function setExtra($extra, int $id)
     {
         $this->shared = $extra;
         $this->id = $id;
@@ -478,7 +478,7 @@ class Connection extends Session
      *
      * @return MTProto
      */
-    public function getExtra(): MTProto
+    public function getExtra()
     {
         return $this->API;
     }
diff --git a/src/danog/MadelineProto/DataCenterConnection.php b/src/danog/MadelineProto/DataCenterConnection.php
index 9276f66b..2e1c915a 100644
--- a/src/danog/MadelineProto/DataCenterConnection.php
+++ b/src/danog/MadelineProto/DataCenterConnection.php
@@ -597,7 +597,7 @@ class DataCenterConnection implements JsonSerializable
      *
      * @return void
      */
-    public function setExtra(MTProto $API)
+    public function setExtra($API)
     {
         $this->API = $API;
     }
@@ -606,7 +606,7 @@ class DataCenterConnection implements JsonSerializable
      *
      * @return MTProto
      */
-    public function getExtra(): MTProto
+    public function getExtra()
     {
         return $this->API;
     }
diff --git a/src/danog/MadelineProto/MTProtoSession/CallHandler.php b/src/danog/MadelineProto/MTProtoSession/CallHandler.php
index 6edb2f30..b91f987c 100644
--- a/src/danog/MadelineProto/MTProtoSession/CallHandler.php
+++ b/src/danog/MadelineProto/MTProtoSession/CallHandler.php
@@ -87,20 +87,21 @@ trait CallHandler
     public function methodCallAsyncRead(string $method, $args = [], array $aargs = ['msg_id' => null]): Promise
     {
         $deferred = new Deferred();
-        $this->methodCallAsyncWrite($method, $args, $aargs)->onResolve(function ($e, $read_deferred) use ($deferred) {
-            if ($e) {
-                $deferred->fail($e);
-            } else {
-                if (\is_array($read_deferred)) {
-                    $read_deferred = \array_map(function ($value) {
-                        return $value->promise();
-                    }, $read_deferred);
-                    $deferred->resolve(all($read_deferred));
+        $this->methodCallAsyncWrite($method, $args, $aargs)->onResolve(
+            static function (\Throwable $e, $readDeferred) use ($deferred): void {
+                if ($e) {
+                    $deferred->fail($e);
                 } else {
-                    $deferred->resolve($read_deferred->promise());
+                    if (\is_array($readDeferred)) {
+                        $readDeferred = \array_map(fn (Deferred $value) => $value->promise(), $readDeferred);
+                        $deferred->resolve(all($readDeferred));
+                    } else {
+                        $readDeferred->promise()->onResolve(fn(\Throwable $e, $res) => var_dump($e, $res));
+                        $deferred->resolve($readDeferred->promise());
+                    }
                 }
             }
-        });
+        );
         return $aargs['noResponse'] ?? false ? new Success() : $deferred->promise();
     }
     /**
diff --git a/src/danog/MadelineProto/Stream/MTProtoTransport/FullStream.php b/src/danog/MadelineProto/Stream/MTProtoTransport/FullStream.php
index a92178d6..6aa2adee 100644
--- a/src/danog/MadelineProto/Stream/MTProtoTransport/FullStream.php
+++ b/src/danog/MadelineProto/Stream/MTProtoTransport/FullStream.php
@@ -46,9 +46,9 @@ class FullStream implements BufferedStreamInterface, MTProtoBufferInterface
      *
      * @param ConnectionContext $ctx
      *
-     * @return Promise
+     * @return \Generator
      */
-    public function connect(ConnectionContext $ctx, string $header = ''): Promise
+    public function connect(ConnectionContext $ctx, string $header = ''): \Generator
     {
         $this->in_seq_no = -1;
         $this->out_seq_no = -1;
diff --git a/src/danog/MadelineProto/Stream/Transport/WsStream.php b/src/danog/MadelineProto/Stream/Transport/WsStream.php
index d22c6996..217c4ba9 100644
--- a/src/danog/MadelineProto/Stream/Transport/WsStream.php
+++ b/src/danog/MadelineProto/Stream/Transport/WsStream.php
@@ -64,7 +64,7 @@ class WsStream implements RawStreamInterface, ProxyStreamInterface
      */
     public function connect(ConnectionContext $ctx, string $header = ''): \Generator
     {
-        if (!\class_exists(Connector::class)) {
+        if (!\class_exists(Handshake::class)) {
             throw new \danog\MadelineProto\Exception('Please install amphp/websocket-client by running "composer require amphp/websocket-client:dev-master"');
         }
         $this->dc = $ctx->getIntDc();
diff --git a/src/danog/MadelineProto/TL/Conversion/BotAPIFiles.php b/src/danog/MadelineProto/TL/Conversion/BotAPIFiles.php
index 3c058625..1de8a07f 100644
--- a/src/danog/MadelineProto/TL/Conversion/BotAPIFiles.php
+++ b/src/danog/MadelineProto/TL/Conversion/BotAPIFiles.php
@@ -111,7 +111,7 @@ trait BotAPIFiles
                 return $res;
             case THUMBNAIL:
                 $res['InputFileLocation'] = [
-                    '_' => $photoSize->getThumbFileType() <= PHOTO ? 'inputPhotoFileLocation' : 'inputDocumentFileLocation',
+                    '_' => $photoSize->getThumbFileType() <= PHOTO ? 'inputDocumentFileLocation' : 'inputPhotoFileLocation',
                     'id' => $fileId->getId(),
                     'access_hash' => $fileId->getAccessHash(),
                     'file_reference' => $fileId->getFileReference(),
@@ -204,7 +204,7 @@ trait BotAPIFiles
             'file_reference' => $fileId->getFileReference(),
             'dc_id' => $fileId->getDcId(),
             'mime_type' => '',
-            'attributes' => [$attribute]
+            'attributes' => $attribute ? [$attribute] : []
         ];
         $res['MessageMedia'] = ['_' => 'messageMediaDocument', 'document' => $constructor, 'caption' => ''];
         return $res;
diff --git a/tests/danog/MadelineProto/API.php b/tests/danog/MadelineProto/API.php
deleted file mode 100644
index 1f1fb330..00000000
--- a/tests/danog/MadelineProto/API.php
+++ /dev/null
@@ -1,59 +0,0 @@
-<?php
-
-use PHPUnit\Framework\TestCase;
-
-final class APITest extends TestCase
-{
-    /**
-     * @dataProvider protocolProvider
-     *
-     * @return void
-     */
-    public function testCanUseProtocol($transport, $obfuscated, $protocol, $test_mode, $ipv6): void
-    {
-        $ping = ['ping_id' => \random_int(PHP_INT_MIN, PHP_INT_MAX)];
-        $MadelineProto = new \danog\MadelineProto\API(
-            [
-                'app_info' => [
-                    'api_id'   => 25628,
-                    'api_hash' => '1fe17cda7d355166cdaa71f04122873c',
-                ],
-                'connection_settings' => [
-                    'all' => [
-                        'ipv6'       => $ipv6,
-                        'test_mode'  => $test_mode,
-                        'protocol'   => $protocol,
-                        'obfuscated' => $obfuscated,
-                        'transport'  => $transport,
-                    ],
-                ],
-            ]
-        );
-        $pong = $MadelineProto->ping($ping);
-        $this->assertContainsEquals('_', $pong, 'pong');
-        $this->assertContainsEquals('ping_id', $pong, $ping['ping_id']);
-    }
-
-    public function protocolProvider(): \Generator
-    {
-        foreach ([false, true] as $test_mode) {
-            foreach ([false, true] as $ipv6) {
-                foreach (['tcp', 'ws', 'wss'] as $transport) {
-                    foreach ([true, false] as $obfuscated) {
-                        if ($transport !== 'tcp' && !$obfuscated) {
-                            continue;
-                        }
-                        foreach (['tcp_abridged', 'tcp_intermediate', 'tcp_intermediate_padded', 'tcp_full'] as $protocol) {
-                            if ($protocol === 'tcp_full' && $obfuscated) {
-                                continue;
-                            }
-                            yield [$transport, $obfuscated, $protocol, $test_mode, $ipv6];
-                        }
-                    }
-                }
-                yield ['tcp', false, 'http', $test_mode, $ipv6];
-                yield ['tcp', false, 'https', $test_mode, $ipv6];
-            }
-        }
-    }
-}
diff --git a/tests/danog/MadelineProto/DataCenterTest.php b/tests/danog/MadelineProto/DataCenterTest.php
new file mode 100644
index 00000000..39c9d731
--- /dev/null
+++ b/tests/danog/MadelineProto/DataCenterTest.php
@@ -0,0 +1,94 @@
+<?php
+
+namespace danog\MadelineProto\Test;
+
+use danog\MadelineProto\DataCenter;
+use danog\MadelineProto\Logger;
+use danog\MadelineProto\MTProto;
+use danog\MadelineProto\Stream\Transport\DefaultStream;
+use danog\MadelineProto\Tools;
+use PHPUnit\Framework\TestCase;
+
+final class DataCenterTest extends TestCase
+{
+    /**
+     * Protocol connection test.
+     *
+     * @param string  $transport  Transport name
+     * @param boolean $obfuscated Obfuscation
+     * @param string  $protocol   Protocol name
+     * @param boolean $test_mode  Test mode
+     * @param boolean $ipv6       IPv6
+     *
+     * @dataProvider protocolProvider
+     *
+     * @return void
+     */
+    public function testCanUseProtocol(string $transport, bool $obfuscated, string $protocol, bool $test_mode, bool $ipv6): void
+    {
+        $settings = MTProto::getSettings(
+            [
+                'connection_settings' => [
+                    'all' => [
+                        'ipv6'       => $ipv6,
+                        'test_mode'  => $test_mode,
+                        'protocol'   => $protocol,
+                        'obfuscated' => $obfuscated,
+                        'transport'  => $transport
+                    ],
+                ]
+            ]
+        );
+        $datacenter = new DataCenter(
+            new class($settings) {
+                /**
+                 * Constructor.
+                 * 
+                 * @param array $settings Logger settings
+                 */
+                public function __construct(array $settings)
+                {
+                    $this->logger = Logger::getLoggerFromSettings($settings);
+                    $this->settings = $settings;
+                }
+                /**
+                 * Get logger.
+                 *
+                 * @return Logger
+                 */
+                public function getLogger(): Logger
+                {
+                    return $this->logger;
+                }
+            },
+            $settings['connection'],
+            $settings['connection_settings'],
+        );
+
+        Tools::wait($datacenter->dcConnect(2));
+        $this->assertTrue(true);
+    }
+
+    public function protocolProvider(): \Generator
+    {
+        foreach ([false, true] as $test_mode) {
+            foreach ([false, true] as $ipv6) {
+                foreach (['tcp', 'ws', 'wss'] as $transport) {
+                    foreach ([true, false] as $obfuscated) {
+                        if ($transport !== 'tcp' && !$obfuscated) {
+                            continue;
+                        }
+                        foreach (['abridged', 'intermediate', 'intermediate_padded', 'full'] as $protocol) {
+                            if ($protocol === 'full' && $obfuscated) {
+                                continue;
+                            }
+                            yield [$transport, $obfuscated, $protocol, $test_mode, $ipv6];
+                        }
+                    }
+                }
+                yield ['tcp', false, 'http', $test_mode, $ipv6];
+                yield ['tcp', false, 'https', $test_mode, $ipv6];
+            }
+        }
+    }
+}
diff --git a/tests/danog/MadelineProto/FileIdTest.php b/tests/danog/MadelineProto/FileIdTest.php
new file mode 100644
index 00000000..2888a5c6
--- /dev/null
+++ b/tests/danog/MadelineProto/FileIdTest.php
@@ -0,0 +1,140 @@
+<?php
+
+namespace danog\MadelineProto\Test;
+
+use CURLFile;
+use danog\Decoder\FileId;
+use danog\MadelineProto\API;
+use danog\MadelineProto\Logger;
+use PHPUnit\Framework\TestCase;
+
+class FileIdTest extends TestCase
+{
+    /**
+     * MadelineProto instance.
+     *
+     * @var API
+     */
+    protected static $MadelineProto;
+
+    /**
+     * Setup MadelineProto instance.
+     *
+     * @return void
+     */
+    public static function setUpBeforeClass(): void
+    {
+        self::$MadelineProto = new API(
+            [
+                'app_info' => [
+                    'api_id' => \getenv('API_ID'),
+                    'api_hash' => \getenv('API_HASH'),
+                ],
+                'logger' => [
+                    'logger' => Logger::ECHO_LOGGER,
+                    'logger_level' => Logger::ULTRA_VERBOSE
+                ]
+            ]
+        );
+        self::$MadelineProto->botLogin(\getenv('BOT_TOKEN'));
+    }
+
+    /**
+     * @param string $fileId File ID
+     * @param string $type   Expected type
+     *
+     * @dataProvider provideFileIdsAndType
+     */
+    public function testDownload(string $type, string $fileIdStr, string $uniqueFileIdStr)
+    {
+        self::$MadelineProto->downloadToFile($fileIdStr, '/dev/null');
+    }
+    /**
+     * @param string $fileId File ID
+     * @param string $type   Expected type
+     *
+     * @dataProvider provideFileIdsAndType
+     */
+    public function testResend(string $type, string $fileIdStr, string $uniqueFileIdStr)
+    {
+        self::$MadelineProto->messages->sendMedia(
+            [
+                'peer' => \getenv('DEST'),
+                'media' => $fileIdStr
+            ]
+        );
+    }
+
+    public function provideFileIdsAndType(): \Generator
+    {
+        $dest = \getenv('DEST');
+        $token = \getenv('BOT_TOKEN');
+        foreach ($this->provideChats() as $chat) {
+            $result = \json_decode(\file_get_contents("https://api.telegram.org/bot$token/getChat?chat_id=$chat"), true)['result']['photo'];
+            yield [
+                'profile_photo',
+                $result['small_file_id'],
+                $result['small_file_unique_id'],
+            ];
+            yield [
+                'profile_photo',
+                $result['big_file_id'],
+                $result['big_file_unique_id'],
+            ];
+        }
+        foreach ($this->provideUrls() as $type => $url) {
+            if ($type === 'video_note') {
+                \copy($url, \basename($url));
+
+                $handle = \curl_init("https://api.telegram.org/bot$token/sendVideoNote?chat_id=$dest");
+                \curl_setopt($handle, CURLOPT_POST, true);
+                \curl_setopt($handle, CURLOPT_POSTFIELDS, [
+                    $type => new CURLFile(\basename($url))
+                ]);
+                \curl_setopt($handle, CURLOPT_RETURNTRANSFER, true);
+                $botResult = \json_decode(\curl_exec($handle), true);
+                \curl_close($handle);
+
+                \unlink(\basename($url));
+            } else {
+                $botResult = \json_decode(\file_get_contents("https://api.telegram.org/bot$token/send$type?chat_id=$dest&$type=$url"), true);
+            }
+            $botResult = $botResult['result'][$type];
+            if ($type !== 'photo') {
+                $botResult = [$botResult];
+            }
+            foreach ($botResult as $subResult) {
+                yield [
+                    $type,
+                    $subResult['file_id'],
+                    $subResult['file_unique_id']
+                ];
+                if (isset($subResult['thumb'])) {
+                    yield [
+                        'thumbnail',
+                        $subResult['thumb']['file_id'],
+                        $subResult['thumb']['file_unique_id']
+                    ];
+                }
+            }
+        }
+        return $result;
+    }
+    public function provideChats(): array
+    {
+        return [\getenv('DEST'), '@MadelineProto'];
+    }
+    public function provideUrls(): array
+    {
+        return [
+            'sticker' => 'https://github.com/danog/MadelineProto/blob/master/tests/lel.webp?raw=true',
+            'photo' => 'https://github.com/danog/MadelineProto/blob/master/tests/faust.jpg',
+            'audio' => 'https://github.com/danog/MadelineProto/blob/master/tests/mosconi.mp3?raw=true',
+            'video' => 'https://github.com/danog/MadelineProto/blob/master/tests/swing.mp4?raw=true',
+            'animation' => 'https://github.com/danog/MadelineProto/blob/master/tests/pony.mp4?raw=true',
+            'document' => 'https://github.com/danog/danog.github.io/raw/master/lol/index_htm_files/0.gif',
+            'voice' => 'https://daniil.it/audio_2020-02-01_18-09-08.ogg',
+            //'video_note' => 'https://daniil.it/round.mp4'
+        ];
+    }
+}
diff --git a/tests/phpunit.xml b/tests/phpunit.xml
index a7acb4db..88cb5382 100644
--- a/tests/phpunit.xml
+++ b/tests/phpunit.xml
@@ -1,7 +1,20 @@
 <?xml version="1.0" encoding="UTF-8"?>
-  <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/7.1/phpunit.xsd"> 
-    <php>
-      <const name="MADELINEPROTO_TEST" value="pony"/>
-    </php>
-  </phpunit>
-
+<phpunit
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/6.0/phpunit.xsd"
+        backupGlobals="false"
+        backupStaticAttributes="false"
+        bootstrap="../vendor/autoload.php"
+        colors="true"
+        convertErrorsToExceptions="true"
+        convertNoticesToExceptions="true"
+        convertWarningsToExceptions="true"
+        processIsolation="false"
+        stopOnFailure="false"
+>
+    <testsuites>
+        <testsuite name="Main">
+            <directory>../tests</directory>
+        </testsuite>
+    </testsuites>
+</phpunit>