Merge pull request #60 from ratchetphp/v0.4

PHP 7.4 as new minimum requirement and PHP 8 compatibility
2025-02-23 20:18:22 -05:00 · 2025-02-23 20:18:22 -05:00 · 859d95f85d
commit 859d95f85d
parent 82760a7616 3a6e857170
30 changed files with 520 additions and 639 deletions
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@ -6,22 +6,24 @@ on:

 jobs:
  PHPUnit:
-    name: PHPUnit (PHP ${{ matrix.php }})(${{ matrix.env }})
-    runs-on: ubuntu-20.04
+    name: PHPUnit (PHP ${{ matrix.php }})(${{ matrix.env }}) on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
+        os:
+          - ubuntu-22.04
        env:
          - client
          - server
        php:
          - 7.4
-          - 7.3
-          - 7.2
-          - 7.1
-          - 7.0
-          - 5.6
+          - 8.0
+          - 8.1
+          - 8.2
+          - 8.3
+          - 8.4
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
      - name: Setup PHP
        uses: shivammathur/setup-php@v2
        with:
@ -33,11 +35,4 @@ jobs:
      - run: sh tests/ab/run_ab_tests.sh
        env:
            ABTEST: ${{ matrix.env }}
-            SKIP_DEFLATE: _skip_deflate
-        if: ${{ matrix.php <= 5.6 }}
-
-      - run: sh tests/ab/run_ab_tests.sh
-        env:
-            ABTEST: ${{ matrix.env }}
-        if: ${{ matrix.php >= 7.0 }}
      - run: vendor/bin/phpunit --verbose
--- a/.gitignore
+++ b/.gitignore
@ -1,3 +1,4 @@
+.phpunit.result.cache
 composer.lock
 vendor
 tests/ab/reports
--- a/composer.json
+++ b/composer.json
@ -26,12 +26,14 @@
        }
    },
    "require": {
-        "php": ">=5.4.2",
-        "guzzlehttp/psr7": "^2 || ^1.7"
+        "php": ">=7.4",
+        "psr/http-factory-implementation": "^1.0",
+        "symfony/polyfill-php80": "^1.15"
    },
    "require-dev": {
-        "phpunit/phpunit": "^5.7",
-        "react/socket": "^1.3"
+        "phpunit/phpunit": "^9.5",
+        "react/socket": "^1.3",
+        "guzzlehttp/psr7": "^2.7"
    },
    "scripts": {
        "abtest-client": "ABTEST=client && sh tests/ab/run_ab_tests.sh",
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@ -1,27 +1,22 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit
        forceCoversAnnotation="true"
-        mapTestClassNameToCoveredClassName="true"
        bootstrap="tests/bootstrap.php"
        colors="true"
        backupGlobals="false"
        backupStaticAttributes="false"
-        syntaxCheck="false"
        stopOnError="false"
        >

    <testsuites>
        <testsuite name="tests">
-            <directory>tests</directory>
-            <exclude>
-                <directory>test/ab</directory>
-            </exclude>
+            <directory>./tests</directory>
        </testsuite>
    </testsuites>

-    <filter>
-        <whitelist>
-            <directory>./src/</directory>
-        </whitelist>
-    </filter>
+    <coverage processUncoveredFiles="true">
+        <include>
+            <directory suffix=".php">./src</directory>
+        </include>
+    </coverage>
 </phpunit>
--- a/src/Handshake/ClientNegotiator.php
+++ b/src/Handshake/ClientNegotiator.php
@ -3,38 +3,35 @@ namespace Ratchet\RFC6455\Handshake;
 use Psr\Http\Message\RequestInterface;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\UriInterface;
-use GuzzleHttp\Psr7\Request;
+use Psr\Http\Message\RequestFactoryInterface;

 class ClientNegotiator {
-    /**
-     * @var ResponseVerifier
-     */
-    private $verifier;
+    private ResponseVerifier $verifier;

-    /**
-     * @var \Psr\Http\Message\RequestInterface
-     */
-    private $defaultHeader;
+    private RequestInterface $defaultHeader;

-    function __construct(PermessageDeflateOptions $perMessageDeflateOptions = null) {
+    private RequestFactoryInterface $requestFactory;
+
+    public function __construct(
+        RequestFactoryInterface $requestFactory,
+        ?PermessageDeflateOptions $perMessageDeflateOptions = null
+    ) {
        $this->verifier = new ResponseVerifier;
+        $this->requestFactory = $requestFactory;

-        $this->defaultHeader = new Request('GET', '', [
-            'Connection'            => 'Upgrade'
-          , 'Upgrade'               => 'websocket'
-          , 'Sec-WebSocket-Version' => $this->getVersion()
-          , 'User-Agent'            => "Ratchet"
-        ]);
+        $this->defaultHeader = $this->requestFactory
+            ->createRequest('GET', '')
+            ->withHeader('Connection'           , 'Upgrade')
+            ->withHeader('Upgrade'              , 'websocket')
+            ->withHeader('Sec-WebSocket-Version', $this->getVersion())
+            ->withHeader('User-Agent'           , 'Ratchet');

-        if ($perMessageDeflateOptions === null) {
-            $perMessageDeflateOptions = PermessageDeflateOptions::createDisabled();
-        }
+        $perMessageDeflateOptions ??= PermessageDeflateOptions::createDisabled();

        // https://bugs.php.net/bug.php?id=73373
        // https://bugs.php.net/bug.php?id=74240 - need >=7.1.4 or >=7.0.18
-        if ($perMessageDeflateOptions->isEnabled() &&
-            !PermessageDeflateOptions::permessageDeflateSupported()) {
-            trigger_error('permessage-deflate is being disabled because it is not support by your PHP version.', E_USER_NOTICE);
+        if ($perMessageDeflateOptions->isEnabled() && !PermessageDeflateOptions::permessageDeflateSupported()) {
+            trigger_error('permessage-deflate is being disabled because it is not supported by your PHP version.', E_USER_NOTICE);
            $perMessageDeflateOptions = PermessageDeflateOptions::createDisabled();
        }
        if ($perMessageDeflateOptions->isEnabled() && !function_exists('deflate_add')) {
@ -45,16 +42,16 @@ class ClientNegotiator {
        $this->defaultHeader = $perMessageDeflateOptions->addHeaderToRequest($this->defaultHeader);
    }

-    public function generateRequest(UriInterface $uri) {
+    public function generateRequest(UriInterface $uri): RequestInterface {
        return $this->defaultHeader->withUri($uri)
-            ->withHeader("Sec-WebSocket-Key", $this->generateKey());
+            ->withHeader('Sec-WebSocket-Key', $this->generateKey());
    }

-    public function validateResponse(RequestInterface $request, ResponseInterface $response) {
+    public function validateResponse(RequestInterface $request, ResponseInterface $response): bool {
        return $this->verifier->verifyAll($request, $response);
    }

-    public function generateKey() {
+    public function generateKey(): string {
        $chars     = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwzyz1234567890+/=';
        $charRange = strlen($chars) - 1;
        $key       = '';
@ -65,7 +62,7 @@ class ClientNegotiator {
        return base64_encode($key);
    }

-    public function getVersion() {
+    public function getVersion(): int {
        return 13;
    }
 }
--- a/src/Handshake/NegotiatorInterface.php
+++ b/src/Handshake/NegotiatorInterface.php
@ -1,6 +1,7 @@
 <?php
 namespace Ratchet\RFC6455\Handshake;
 use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\ResponseInterface;

 /**
 * A standard interface for interacting with the various version of the WebSocket protocol
@ -14,34 +15,34 @@ interface NegotiatorInterface {
     * @param RequestInterface $request
     * @return bool
     */
-    function isProtocol(RequestInterface $request);
+    public function isProtocol(RequestInterface $request): bool;

    /**
     * Although the version has a name associated with it the integer returned is the proper identification
     * @return int
     */
-    function getVersionNumber();
+    public function getVersionNumber(): int;

    /**
     * Perform the handshake and return the response headers
     * @param RequestInterface $request
-     * @return \Psr\Http\Message\ResponseInterface
+     * @return ResponseInterface
     */
-    function handshake(RequestInterface $request);
+    public function handshake(RequestInterface $request): ResponseInterface;

    /**
     * Add supported protocols. If the request has any matching the response will include one
     * @param array $protocols
     */
-    function setSupportedSubProtocols(array $protocols);
+    public function setSupportedSubProtocols(array $protocols): void;

    /**
     * If enabled and support for a subprotocol has been added handshake
     *  will not upgrade if a match between request and supported subprotocols
     * @param boolean $enable
     * @todo Consider extending this interface and moving this there.
-     *       The spec does says the server can fail for this reason, but
+     *       The spec does say the server can fail for this reason, but
     *       it is not a requirement. This is an implementation detail.
     */
-    function setStrictSubProtocolCheck($enable);
+    public function setStrictSubProtocolCheck(bool $enable): void;
 }
--- a/src/Handshake/PermessageDeflateOptions.php
+++ b/src/Handshake/PermessageDeflateOptions.php
@ -8,21 +8,21 @@ use Psr\Http\Message\ResponseInterface;

 final class PermessageDeflateOptions
 {
-    const MAX_WINDOW_BITS = 15;
-    /* this is a private instead of const for 5.4 compatibility */
-    private static $VALID_BITS = ['8', '9', '10', '11', '12', '13', '14', '15'];
+    public const MAX_WINDOW_BITS = 15;

-    private $deflateEnabled = false;
+    private const VALID_BITS = [8, 9, 10, 11, 12, 13, 14, 15];

-    private $server_no_context_takeover;
-    private $client_no_context_takeover;
-    private $server_max_window_bits;
-    private $client_max_window_bits;
+    private bool $deflateEnabled = false;
+
+    private ?bool $server_no_context_takeover = null;
+    private ?bool $client_no_context_takeover = null;
+    private ?int $server_max_window_bits = null;
+    private ?int $client_max_window_bits = null;

    private function __construct() { }

    public static function createEnabled() {
-        $new                             = new static();
+        $new                             = new self();
        $new->deflateEnabled             = true;
        $new->client_max_window_bits     = self::MAX_WINDOW_BITS;
        $new->client_no_context_takeover = false;
@ -33,35 +33,35 @@ final class PermessageDeflateOptions
    }

    public static function createDisabled() {
-        return new static();
+        return new self();
    }

-    public function withClientNoContextTakeover() {
+    public function withClientNoContextTakeover(): self {
        $new = clone $this;
        $new->client_no_context_takeover = true;
        return $new;
    }

-    public function withoutClientNoContextTakeover() {
+    public function withoutClientNoContextTakeover(): self {
        $new = clone $this;
        $new->client_no_context_takeover = false;
        return $new;
    }

-    public function withServerNoContextTakeover() {
+    public function withServerNoContextTakeover(): self {
        $new = clone $this;
        $new->server_no_context_takeover = true;
        return $new;
    }

-    public function withoutServerNoContextTakeover() {
+    public function withoutServerNoContextTakeover(): self {
        $new = clone $this;
        $new->server_no_context_takeover = false;
        return $new;
    }

-    public function withServerMaxWindowBits($bits = self::MAX_WINDOW_BITS) {
-        if (!in_array($bits, self::$VALID_BITS)) {
+    public function withServerMaxWindowBits(int $bits = self::MAX_WINDOW_BITS): self {
+        if (!in_array($bits, self::VALID_BITS)) {
            throw new \Exception('server_max_window_bits must have a value between 8 and 15.');
        }
        $new = clone $this;
@ -69,8 +69,8 @@ final class PermessageDeflateOptions
        return $new;
    }

-    public function withClientMaxWindowBits($bits = self::MAX_WINDOW_BITS) {
-        if (!in_array($bits, self::$VALID_BITS)) {
+    public function withClientMaxWindowBits(int $bits = self::MAX_WINDOW_BITS): self {
+        if (!in_array($bits, self::VALID_BITS)) {
            throw new \Exception('client_max_window_bits must have a value between 8 and 15.');
        }
        $new = clone $this;
@ -86,7 +86,7 @@ final class PermessageDeflateOptions
     * @return PermessageDeflateOptions[]
     * @throws \Exception
     */
-    public static function fromRequestOrResponse(MessageInterface $requestOrResponse) {
+    public static function fromRequestOrResponse(MessageInterface $requestOrResponse): array {
        $optionSets = [];

        $extHeader = preg_replace('/\s+/', '', join(', ', $requestOrResponse->getHeader('Sec-Websocket-Extensions')));
@ -103,7 +103,7 @@ final class PermessageDeflateOptions
            }

            array_shift($parts);
-            $options                 = new static();
+            $options                 = new self();
            $options->deflateEnabled = true;
            foreach ($parts as $part) {
                $kv = explode('=', $part);
@ -119,15 +119,18 @@ final class PermessageDeflateOptions
                        $value = true;
                        break;
                    case "server_max_window_bits":
-                        if (!in_array($value, self::$VALID_BITS)) {
+                        $value = (int) $value;
+                        if (!in_array($value, self::VALID_BITS)) {
                            throw new InvalidPermessageDeflateOptionsException($key . ' must have a value between 8 and 15.');
                        }
                        break;
                    case "client_max_window_bits":
                        if ($value === null) {
-                            $value = '15';
+                            $value = 15;
+                        } else {
+                            $value = (int) $value;
                        }
-                        if (!in_array($value, self::$VALID_BITS)) {
+                        if (!in_array($value, self::VALID_BITS)) {
                            throw new InvalidPermessageDeflateOptionsException($key . ' must have no value or a value between 8 and 15.');
                        }
                        break;
@ -154,39 +157,39 @@ final class PermessageDeflateOptions
        }

        // always put a disabled on the end
-        $optionSets[] = new static();
+        $optionSets[] = new self();

        return $optionSets;
    }

    /**
-     * @return mixed
+     * @return bool|null
     */
-    public function getServerNoContextTakeover()
+    public function getServerNoContextTakeover(): ?bool
    {
        return $this->server_no_context_takeover;
    }

    /**
-     * @return mixed
+     * @return bool|null
     */
-    public function getClientNoContextTakeover()
+    public function getClientNoContextTakeover(): ?bool
    {
        return $this->client_no_context_takeover;
    }

    /**
-     * @return mixed
+     * @return int|null
     */
-    public function getServerMaxWindowBits()
+    public function getServerMaxWindowBits(): ?int
    {
        return $this->server_max_window_bits;
    }

    /**
-     * @return mixed
+     * @return int|null
     */
-    public function getClientMaxWindowBits()
+    public function getClientMaxWindowBits(): ?int
    {
        return $this->client_max_window_bits;
    }
@ -194,7 +197,7 @@ final class PermessageDeflateOptions
    /**
     * @return bool
     */
-    public function isEnabled()
+    public function isEnabled(): bool
    {
        return $this->deflateEnabled;
    }
@ -203,7 +206,7 @@ final class PermessageDeflateOptions
     * @param ResponseInterface $response
     * @return ResponseInterface
     */
-    public function addHeaderToResponse(ResponseInterface $response)
+    public function addHeaderToResponse(ResponseInterface $response): ResponseInterface
    {
        if (!$this->deflateEnabled) {
            return $response;
@ -226,7 +229,7 @@ final class PermessageDeflateOptions
        return $response->withAddedHeader('Sec-Websocket-Extensions', $header);
    }

-    public function addHeaderToRequest(RequestInterface $request) {
+    public function addHeaderToRequest(RequestInterface $request): RequestInterface {
        if (!$this->deflateEnabled) {
            return $request;
        }
@ -249,7 +252,7 @@ final class PermessageDeflateOptions
        return $request->withAddedHeader('Sec-Websocket-Extensions', $header);
    }

-    public static function permessageDeflateSupported($version = PHP_VERSION) {
+    public static function permessageDeflateSupported(string $version = PHP_VERSION): bool {
        if (!function_exists('deflate_init')) {
            return false;
        }
--- a/src/Handshake/RequestVerifier.php
+++ b/src/Handshake/RequestVerifier.php
@ -8,14 +8,14 @@ use Psr\Http\Message\RequestInterface;
 * @todo Currently just returning invalid - should consider returning appropriate HTTP status code error #s
 */
 class RequestVerifier {
-    const VERSION = 13;
+    public const VERSION = 13;

    /**
     * Given an array of the headers this method will run through all verification methods
     * @param RequestInterface $request
     * @return bool TRUE if all headers are valid, FALSE if 1 or more were invalid
     */
-    public function verifyAll(RequestInterface $request) {
+    public function verifyAll(RequestInterface $request): bool {
        $passes = 0;

        $passes += (int)$this->verifyMethod($request->getMethod());
@ -27,7 +27,7 @@ class RequestVerifier {
        $passes += (int)$this->verifyKey($request->getHeader('Sec-WebSocket-Key'));
        $passes += (int)$this->verifyVersion($request->getHeader('Sec-WebSocket-Version'));

-        return (8 === $passes);
+        return 8 === $passes;
    }

    /**
@ -35,8 +35,8 @@ class RequestVerifier {
     * @param string
     * @return bool
     */
-    public function verifyMethod($val) {
-        return ('get' === strtolower($val));
+    public function verifyMethod(string $val): bool {
+        return 'get' === strtolower($val);
    }

    /**
@ -44,15 +44,15 @@ class RequestVerifier {
     * @param string|int
     * @return bool
     */
-    public function verifyHTTPVersion($val) {
-        return (1.1 <= (double)$val);
+    public function verifyHTTPVersion($val): bool {
+        return 1.1 <= (double)$val;
    }

    /**
     * @param string
     * @return bool
     */
-    public function verifyRequestURI($val) {
+    public function verifyRequestURI(string $val): bool {
        if ($val[0] !== '/') {
            return false;
        }
@ -73,8 +73,8 @@ class RequestVerifier {
     * @return bool
     * @todo Once I fix HTTP::getHeaders just verify this isn't NULL or empty...or maybe need to verify it's a valid domain??? Or should it equal $_SERVER['HOST'] ?
     */
-    public function verifyHost(array $hostHeader) {
-        return (1 === count($hostHeader));
+    public function verifyHost(array $hostHeader): bool {
+        return 1 === count($hostHeader);
    }

    /**
@ -82,8 +82,8 @@ class RequestVerifier {
     * @param  array $upgradeHeader MUST equal "websocket"
     * @return bool
     */
-    public function verifyUpgradeRequest(array $upgradeHeader) {
-        return (1 === count($upgradeHeader) && 'websocket' === strtolower($upgradeHeader[0]));
+    public function verifyUpgradeRequest(array $upgradeHeader): bool {
+        return 1 === count($upgradeHeader) && 'websocket' === strtolower($upgradeHeader[0]);
    }

    /**
@ -91,13 +91,11 @@ class RequestVerifier {
     * @param  array $connectionHeader MUST include "Upgrade"
     * @return bool
     */
-    public function verifyConnection(array $connectionHeader) {
+    public function verifyConnection(array $connectionHeader): bool {
        foreach ($connectionHeader as $l) {
            $upgrades = array_filter(
                array_map('trim', array_map('strtolower', explode(',', $l))),
-                function ($x) {
-                    return 'upgrade' === $x;
-                }
+                static fn (string $x) => 'upgrade' === $x
            );
            if (count($upgrades) > 0) {
                return true;
@ -113,8 +111,8 @@ class RequestVerifier {
     * @todo The spec says we don't need to base64_decode - can I just check if the length is 24 and not decode?
     * @todo Check the spec to see what the encoding of the key could be
     */
-    public function verifyKey(array $keyHeader) {
-        return (1 === count($keyHeader) && 16 === strlen(base64_decode($keyHeader[0])));
+    public function verifyKey(array $keyHeader): bool {
+        return 1 === count($keyHeader) && 16 === strlen(base64_decode($keyHeader[0]));
    }

    /**
@ -122,33 +120,33 @@ class RequestVerifier {
     * @param string[] $versionHeader MUST equal ["13"]
     * @return bool
     */
-    public function verifyVersion(array $versionHeader) {
-        return (1 === count($versionHeader) && static::VERSION === (int)$versionHeader[0]);
+    public function verifyVersion(array $versionHeader): bool {
+        return 1 === count($versionHeader) && static::VERSION === (int)$versionHeader[0];
    }

    /**
     * @todo Write logic for this method.  See section 4.2.1.8
     */
-    public function verifyProtocol($val) {
+    public function verifyProtocol($val): bool {
+        return true;
    }

    /**
     * @todo Write logic for this method.  See section 4.2.1.9
     */
-    public function verifyExtensions($val) {
+    public function verifyExtensions($val): bool {
+        return true;
    }

-    public function getPermessageDeflateOptions(array $requestHeader, array $responseHeader) {
+    public function getPermessageDeflateOptions(array $requestHeader, array $responseHeader): array {
+        $headerChecker = static fn (string $val) => 'permessage-deflate' === substr($val, 0, strlen('permessage-deflate'));
+
        $deflate = true;
-        if (!isset($requestHeader['Sec-WebSocket-Extensions']) || count(array_filter($requestHeader['Sec-WebSocket-Extensions'], function ($val) {
-            return 'permessage-deflate' === substr($val, 0, strlen('permessage-deflate'));
-        })) === 0) {
+        if (!isset($requestHeader['Sec-WebSocket-Extensions']) || count(array_filter($requestHeader['Sec-WebSocket-Extensions'], $headerChecker)) === 0) {
             $deflate = false;
        }

-        if (!isset($responseHeader['Sec-WebSocket-Extensions']) || count(array_filter($responseHeader['Sec-WebSocket-Extensions'], function ($val) {
-                return 'permessage-deflate' === substr($val, 0, strlen('permessage-deflate'));
-            })) === 0) {
+        if (!isset($responseHeader['Sec-WebSocket-Extensions']) || count(array_filter($responseHeader['Sec-WebSocket-Extensions'], $headerChecker)) === 0) {
            $deflate = false;
        }

--- a/src/Handshake/ResponseVerifier.php
+++ b/src/Handshake/ResponseVerifier.php
@ -4,7 +4,7 @@ use Psr\Http\Message\RequestInterface;
 use Psr\Http\Message\ResponseInterface;

 class ResponseVerifier {
-    public function verifyAll(RequestInterface $request, ResponseInterface $response) {
+    public function verifyAll(RequestInterface $request, ResponseInterface $response): bool {
        $passes = 0;

        $passes += (int)$this->verifyStatus($response->getStatusCode());
@ -26,31 +26,31 @@ class ResponseVerifier {
        return (6 === $passes);
    }

-    public function verifyStatus($status) {
-        return ((int)$status === 101);
+    public function verifyStatus(int $status): bool {
+        return $status === 101;
    }

-    public function verifyUpgrade(array $upgrade) {
-        return (in_array('websocket', array_map('strtolower', $upgrade)));
+    public function verifyUpgrade(array $upgrade): bool {
+        return in_array('websocket', array_map('strtolower', $upgrade));
    }

-    public function verifyConnection(array $connection) {
-        return (in_array('upgrade', array_map('strtolower', $connection)));
+    public function verifyConnection(array $connection): bool {
+        return in_array('upgrade', array_map('strtolower', $connection));
    }

-    public function verifySecWebSocketAccept($swa, $key) {
-        return (
+    public function verifySecWebSocketAccept(array $swa, array $key): bool {
+        return
            1 === count($swa) &&
            1 === count($key) &&
            $swa[0] === $this->sign($key[0])
-        );
+        ;
    }

-    public function sign($key) {
+    public function sign(string $key): string {
        return base64_encode(sha1($key . NegotiatorInterface::GUID, true));
    }

-    public function verifySubProtocol(array $requestHeader, array $responseHeader) {
+    public function verifySubProtocol(array $requestHeader, array $responseHeader): bool {
        if (0 === count($responseHeader)) {
            return true;
        }
@ -60,7 +60,7 @@ class ResponseVerifier {
        return count($responseHeader) === 1 && count(array_intersect($responseHeader, $requestedProtocols)) === 1;
    }

-    public function verifyExtensions(array $requestHeader, array $responseHeader) {
+    public function verifyExtensions(array $requestHeader, array $responseHeader): int {
        if (in_array('permessage-deflate', $responseHeader)) {
            return strpos(implode(',', $requestHeader), 'permessage-deflate') !== false ? 1 : 0;
        }
--- a/src/Handshake/ServerNegotiator.php
+++ b/src/Handshake/ServerNegotiator.php
@ -1,26 +1,32 @@
 <?php
 namespace Ratchet\RFC6455\Handshake;
 use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\ResponseFactoryInterface;
 use GuzzleHttp\Psr7\Response;
+use Psr\Http\Message\ResponseInterface;

 /**
 * The latest version of the WebSocket protocol
 * @todo Unicode: return mb_convert_encoding(pack("N",$u), mb_internal_encoding(), 'UCS-4BE');
 */
 class ServerNegotiator implements NegotiatorInterface {
-    /**
-     * @var \Ratchet\RFC6455\Handshake\RequestVerifier
-     */
-    private $verifier;
+    private RequestVerifier $verifier;

-    private $_supportedSubProtocols = [];
+    private ResponseFactoryInterface $responseFactory;

-    private $_strictSubProtocols = false;
+    private array $_supportedSubProtocols = [];

-    private $enablePerMessageDeflate = false;
+    private bool $_strictSubProtocols = false;

-    public function __construct(RequestVerifier $requestVerifier, $enablePerMessageDeflate = false) {
+    private bool $enablePerMessageDeflate = false;
+
+    public function __construct(
+        RequestVerifier $requestVerifier,
+        ResponseFactoryInterface $responseFactory,
+        $enablePerMessageDeflate = false
+    ) {
        $this->verifier = $requestVerifier;
+        $this->responseFactory = $responseFactory;

        // https://bugs.php.net/bug.php?id=73373
        // https://bugs.php.net/bug.php?id=74240 - need >=7.1.4 or >=7.0.18
@ -38,85 +44,85 @@ class ServerNegotiator implements NegotiatorInterface {
    /**
     * {@inheritdoc}
     */
-    public function isProtocol(RequestInterface $request) {
+    public function isProtocol(RequestInterface $request): bool {
        return $this->verifier->verifyVersion($request->getHeader('Sec-WebSocket-Version'));
    }

    /**
     * {@inheritdoc}
     */
-    public function getVersionNumber() {
+    public function getVersionNumber(): int {
        return RequestVerifier::VERSION;
    }

    /**
     * {@inheritdoc}
     */
-    public function handshake(RequestInterface $request) {
+    public function handshake(RequestInterface $request): ResponseInterface {
+        $response = $this->responseFactory->createResponse();
        if (true !== $this->verifier->verifyMethod($request->getMethod())) {
-            return new Response(405, ['Allow' => 'GET']);
+            return $response->withHeader('Allow', 'GET')->withStatus(405);
        }

        if (true !== $this->verifier->verifyHTTPVersion($request->getProtocolVersion())) {
-            return new Response(505);
+            return $response->withStatus(505);
        }

        if (true !== $this->verifier->verifyRequestURI($request->getUri()->getPath())) {
-            return new Response(400);
+            return $response->withStatus(400);
        }

        if (true !== $this->verifier->verifyHost($request->getHeader('Host'))) {
-            return new Response(400);
+            return $response->withStatus(400);
        }

-        $upgradeSuggestion = [
-            'Connection'             => 'Upgrade',
-            'Upgrade'                => 'websocket',
-            'Sec-WebSocket-Version'  => $this->getVersionNumber()
-        ];
+        $upgradeResponse = $response
+            ->withHeader('Connection'           , 'Upgrade')
+            ->withHeader('Upgrade'              , 'websocket')
+            ->withHeader('Sec-WebSocket-Version', $this->getVersionNumber());
+
        if (count($this->_supportedSubProtocols) > 0) {
-            $upgradeSuggestion['Sec-WebSocket-Protocol'] = implode(', ', array_keys($this->_supportedSubProtocols));
+            $upgradeResponse = $upgradeResponse->withHeader(
+                'Sec-WebSocket-Protocol', implode(', ', array_keys($this->_supportedSubProtocols))
+            );
        }
        if (true !== $this->verifier->verifyUpgradeRequest($request->getHeader('Upgrade'))) {
-            return new Response(426, $upgradeSuggestion, null, '1.1', 'Upgrade header MUST be provided');
+            return $upgradeResponse->withStatus(426, 'Upgrade header MUST be provided');
        }

        if (true !== $this->verifier->verifyConnection($request->getHeader('Connection'))) {
-            return new Response(400, [], null, '1.1', 'Connection Upgrade MUST be requested');
+            return $response->withStatus(400, 'Connection Upgrade MUST be requested');
        }

        if (true !== $this->verifier->verifyKey($request->getHeader('Sec-WebSocket-Key'))) {
-            return new Response(400, [], null, '1.1', 'Invalid Sec-WebSocket-Key');
+            return $response->withStatus(400, 'Invalid Sec-WebSocket-Key');
        }

        if (true !== $this->verifier->verifyVersion($request->getHeader('Sec-WebSocket-Version'))) {
-            return new Response(426, $upgradeSuggestion);
+            return $upgradeResponse->withStatus(426);
        }

-        $headers = [];
        $subProtocols = $request->getHeader('Sec-WebSocket-Protocol');
        if (count($subProtocols) > 0 || (count($this->_supportedSubProtocols) > 0 && $this->_strictSubProtocols)) {
            $subProtocols = array_map('trim', explode(',', implode(',', $subProtocols)));

-            $match = array_reduce($subProtocols, function($accumulator, $protocol) {
-                return $accumulator ?: (isset($this->_supportedSubProtocols[$protocol]) ? $protocol : null);
-            }, null);
+            $match = array_reduce($subProtocols, fn ($accumulator, $protocol) => $accumulator ?: (isset($this->_supportedSubProtocols[$protocol]) ? $protocol : null), null);

            if ($this->_strictSubProtocols && null === $match) {
-                return new Response(426, $upgradeSuggestion, null, '1.1', 'No Sec-WebSocket-Protocols requested supported');
+                return $upgradeResponse->withStatus(426, 'No Sec-WebSocket-Protocols requested supported');
            }

            if (null !== $match) {
-                $headers['Sec-WebSocket-Protocol'] = $match;
+                $response = $response->withHeader('Sec-WebSocket-Protocol', $match);
            }
        }

-        $response = new Response(101, array_merge($headers, [
-            'Upgrade'              => 'websocket'
-            , 'Connection'           => 'Upgrade'
-            , 'Sec-WebSocket-Accept' => $this->sign((string)$request->getHeader('Sec-WebSocket-Key')[0])
-            , 'X-Powered-By'         => 'Ratchet'
-        ]));
+        $response = $response
+            ->withStatus(101)
+            ->withHeader('Upgrade'             , 'websocket')
+            ->withHeader('Connection'          , 'Upgrade')
+            ->withHeader('Sec-WebSocket-Accept', $this->sign((string)$request->getHeader('Sec-WebSocket-Key')[0]))
+            ->withHeader('X-Powered-By'        , 'Ratchet');

        try {
            $perMessageDeflateRequest = PermessageDeflateOptions::fromRequestOrResponse($request)[0];
@ -137,14 +143,14 @@ class ServerNegotiator implements NegotiatorInterface {
     * @return string
     * @internal
     */
-    public function sign($key) {
+    public function sign(string $key): string {
        return base64_encode(sha1($key . static::GUID, true));
    }

    /**
     * @param array $protocols
     */
-    function setSupportedSubProtocols(array $protocols) {
+    public function setSupportedSubProtocols(array $protocols): void {
        $this->_supportedSubProtocols = array_flip($protocols);
    }

@ -153,10 +159,10 @@ class ServerNegotiator implements NegotiatorInterface {
     *  will not upgrade if a match between request and supported subprotocols
     * @param boolean $enable
     * @todo Consider extending this interface and moving this there.
-     *       The spec does says the server can fail for this reason, but
-     * it is not a requirement. This is an implementation detail.
+     *       The spec does say the server can fail for this reason, but
+     *       it is not a requirement. This is an implementation detail.
     */
-    function setStrictSubProtocolCheck($enable) {
-        $this->_strictSubProtocols = (boolean)$enable;
+    public function setStrictSubProtocolCheck(bool $enable): void {
+        $this->_strictSubProtocols = $enable;
    }
 }
--- a/src/Messaging/CloseFrameChecker.php
+++ b/src/Messaging/CloseFrameChecker.php
@ -2,23 +2,19 @@
 namespace Ratchet\RFC6455\Messaging;

 class CloseFrameChecker {
-    private $validCloseCodes = [];
+    private array $validCloseCodes = [
+        Frame::CLOSE_NORMAL,
+        Frame::CLOSE_GOING_AWAY,
+        Frame::CLOSE_PROTOCOL,
+        Frame::CLOSE_BAD_DATA,
+        Frame::CLOSE_BAD_PAYLOAD,
+        Frame::CLOSE_POLICY,
+        Frame::CLOSE_TOO_BIG,
+        Frame::CLOSE_MAND_EXT,
+        Frame::CLOSE_SRV_ERR,
+    ];

-    public function __construct() {
-        $this->validCloseCodes = [
-            Frame::CLOSE_NORMAL,
-            Frame::CLOSE_GOING_AWAY,
-            Frame::CLOSE_PROTOCOL,
-            Frame::CLOSE_BAD_DATA,
-            Frame::CLOSE_BAD_PAYLOAD,
-            Frame::CLOSE_POLICY,
-            Frame::CLOSE_TOO_BIG,
-            Frame::CLOSE_MAND_EXT,
-            Frame::CLOSE_SRV_ERR,
-        ];
-    }
-
-    public function __invoke($val) {
+    public function __invoke(int $val): bool {
        return ($val >= 3000 && $val <= 4999) || in_array($val, $this->validCloseCodes);
    }
 }
--- a/src/Messaging/DataInterface.php
+++ b/src/Messaging/DataInterface.php
@ -1,34 +1,28 @@
 <?php
 namespace Ratchet\RFC6455\Messaging;

-interface DataInterface {
+interface DataInterface extends \Stringable {
    /**
     * Determine if the message is complete or still fragmented
     * @return bool
     */
-    function isCoalesced();
+    public function isCoalesced(): bool;

    /**
     * Get the number of bytes the payload is set to be
     * @return int
     */
-    function getPayloadLength();
+    public function getPayloadLength(): int;

    /**
     * Get the payload (message) sent from peer
     * @return string
     */
-    function getPayload();
+    public function getPayload(): string;

    /**
     * Get raw contents of the message
     * @return string
     */
-    function getContents();
-
-    /**
-     * Should return the unmasked payload received from peer
-     * @return string
-     */
-    function __toString();
+    public function getContents(): string;
 }
--- a/src/Messaging/Frame.php
+++ b/src/Messaging/Frame.php
@ -26,40 +26,34 @@ class Frame implements FrameInterface {

    /**
     * The contents of the frame
-     * @var string
     */
-    protected $data = '';
+    protected string $data = '';

    /**
     * Number of bytes received from the frame
-     * @var int
     */
-    public $bytesRecvd = 0;
+    public int $bytesRecvd = 0;

    /**
     * Number of bytes in the payload (as per framing protocol)
-     * @var int
     */
-    protected $defPayLen = -1;
+    protected int $defPayLen = -1;

    /**
     * If the frame is coalesced this is true
     * This is to prevent doing math every time ::isCoalesced is called
-     * @var boolean
     */
-    private $isCoalesced = false;
+    private bool $isCoalesced = false;

    /**
     * The unpacked first byte of the frame
-     * @var int
     */
-    protected $firstByte = -1;
+    protected int $firstByte = -1;

    /**
     * The unpacked second byte of the frame
-     * @var int
     */
-    protected $secondByte = -1;
+    protected int $secondByte = -1;

    /**
     * @var callable
@ -73,10 +67,8 @@ class Frame implements FrameInterface {
     * @param int         $opcode
     * @param callable<\UnderflowException> $ufExceptionFactory
     */
-    public function __construct($payload = null, $final = true, $opcode = 1, callable $ufExceptionFactory = null) {
-        $this->ufeg = $ufExceptionFactory ?: static function($msg = '') {
-            return new \UnderflowException($msg);
-        };
+    public function __construct(?string $payload = null, bool $final = true, int $opcode = 1, ?callable $ufExceptionFactory = null) {
+        $this->ufeg = $ufExceptionFactory ?: static fn (string $msg = '') => new \UnderflowException($msg);

        if (null === $payload) {
            return;
@ -103,7 +95,7 @@ class Frame implements FrameInterface {
    /**
     * {@inheritdoc}
     */
-    public function isCoalesced() {
+    public function isCoalesced(): bool {
        if (true === $this->isCoalesced) {
            return true;
        }
@ -123,7 +115,7 @@ class Frame implements FrameInterface {
    /**
     * {@inheritdoc}
     */
-    public function addBuffer($buf) {
+    public function addBuffer(string $buf): void {
        $len = strlen($buf);

        $this->data       .= $buf;
@ -141,7 +133,7 @@ class Frame implements FrameInterface {
    /**
     * {@inheritdoc}
     */
-    public function isFinal() {
+    public function isFinal(): bool {
        if (-1 === $this->firstByte) {
            throw call_user_func($this->ufeg, 'Not enough bytes received to determine if this is the final frame in message');
        }
@ -149,7 +141,7 @@ class Frame implements FrameInterface {
        return 128 === ($this->firstByte & 128);
    }

-    public function setRsv1($value = true) {
+    public function setRsv1(bool $value = true): self {
        if (strlen($this->data) == 0) {
            throw new \UnderflowException("Cannot set Rsv1 because there is no data.");
        }
@ -170,7 +162,7 @@ class Frame implements FrameInterface {
     * @return boolean
     * @throws \UnderflowException
     */
-    public function getRsv1() {
+    public function getRsv1(): bool {
        if (-1 === $this->firstByte) {
            throw call_user_func($this->ufeg, 'Not enough bytes received to determine reserved bit');
        }
@ -182,7 +174,7 @@ class Frame implements FrameInterface {
     * @return boolean
     * @throws \UnderflowException
     */
-    public function getRsv2() {
+    public function getRsv2(): bool {
        if (-1 === $this->firstByte) {
            throw call_user_func($this->ufeg, 'Not enough bytes received to determine reserved bit');
        }
@ -194,7 +186,7 @@ class Frame implements FrameInterface {
     * @return boolean
     * @throws \UnderflowException
     */
-    public function getRsv3() {
+    public function getRsv3(): bool {
        if (-1 === $this->firstByte) {
            throw call_user_func($this->ufeg, 'Not enough bytes received to determine reserved bit');
        }
@ -205,7 +197,7 @@ class Frame implements FrameInterface {
    /**
     * {@inheritdoc}
     */
-    public function isMasked() {
+    public function isMasked(): bool {
        if (-1 === $this->secondByte) {
            throw call_user_func($this->ufeg, "Not enough bytes received ({$this->bytesRecvd}) to determine if mask is set");
        }
@ -216,7 +208,7 @@ class Frame implements FrameInterface {
    /**
     * {@inheritdoc}
     */
-    public function getMaskingKey() {
+    public function getMaskingKey(): string {
        if (!$this->isMasked()) {
            return '';
        }
@ -234,7 +226,7 @@ class Frame implements FrameInterface {
     * Create a 4 byte masking key
     * @return string
     */
-    public function generateMaskingKey() {
+    public function generateMaskingKey(): string {
        $mask = '';

        for ($i = 1; $i <= static::MASK_LENGTH; $i++) {
@ -251,7 +243,7 @@ class Frame implements FrameInterface {
     * @throws \InvalidArgumentException If there is an issue with the given masking key
     * @return Frame
     */
-    public function maskPayload($maskingKey = null) {
+    public function maskPayload(?string $maskingKey = null): self {
        if (null === $maskingKey) {
            $maskingKey = $this->generateMaskingKey();
        }
@ -282,7 +274,7 @@ class Frame implements FrameInterface {
     * @throws \UnderFlowException If the frame is not coalesced
     * @return Frame
     */
-    public function unMaskPayload() {
+    public function unMaskPayload(): self {
        if (!$this->isCoalesced()) {
            throw call_user_func($this->ufeg, 'Frame must be coalesced before applying mask');
        }
@ -311,7 +303,7 @@ class Frame implements FrameInterface {
     * @throws \UnderflowException If using the payload but enough hasn't been buffered
     * @return string              The masked string
     */
-    public function applyMask($maskingKey, $payload = null) {
+    public function applyMask(string $maskingKey, ?string $payload = null): string {
        if (null === $payload) {
            if (!$this->isCoalesced()) {
                throw call_user_func($this->ufeg, 'Frame must be coalesced to apply a mask');
@ -332,7 +324,7 @@ class Frame implements FrameInterface {
    /**
     * {@inheritdoc}
     */
-    public function getOpcode() {
+    public function getOpcode(): int {
        if (-1 === $this->firstByte) {
            throw call_user_func($this->ufeg, 'Not enough bytes received to determine opcode');
        }
@ -345,7 +337,7 @@ class Frame implements FrameInterface {
     * @return int
     * @throws \UnderflowException If the buffer doesn't have enough data to determine this
     */
-    protected function getFirstPayloadVal() {
+    protected function getFirstPayloadVal(): int {
        if (-1 === $this->secondByte) {
            throw call_user_func($this->ufeg, 'Not enough bytes received');
        }
@ -357,7 +349,7 @@ class Frame implements FrameInterface {
     * @return int (7|23|71) Number of bits defined for the payload length in the fame
     * @throws \UnderflowException
     */
-    protected function getNumPayloadBits() {
+    protected function getNumPayloadBits(): int {
        if (-1 === $this->secondByte) {
            throw call_user_func($this->ufeg, 'Not enough bytes received');
        }
@ -387,14 +379,14 @@ class Frame implements FrameInterface {
     * This just returns the number of bytes used in the frame to describe the payload length (as opposed to # of bits)
     * @see getNumPayloadBits
     */
-    protected function getNumPayloadBytes() {
+    protected function getNumPayloadBytes(): int {
        return (1 + $this->getNumPayloadBits()) / 8;
    }

    /**
     * {@inheritdoc}
     */
-    public function getPayloadLength() {
+    public function getPayloadLength(): int {
        if ($this->defPayLen !== -1) {
            return $this->defPayLen;
        }
@ -424,7 +416,7 @@ class Frame implements FrameInterface {
    /**
     * {@inheritdoc}
     */
-    public function getPayloadStartingByte() {
+    public function getPayloadStartingByte(): int {
        return 1 + $this->getNumPayloadBytes() + ($this->isMasked() ? static::MASK_LENGTH : 0);
    }

@ -432,7 +424,7 @@ class Frame implements FrameInterface {
     * {@inheritdoc}
     * @todo Consider not checking mask, always returning the payload, masked or not
     */
-    public function getPayload() {
+    public function getPayload(): string {
        if (!$this->isCoalesced()) {
            throw call_user_func($this->ufeg, 'Can not return partial message');
        }
@ -444,11 +436,11 @@ class Frame implements FrameInterface {
     * Get the raw contents of the frame
     * @todo This is untested, make sure the substr is right - trying to return the frame w/o the overflow
     */
-    public function getContents() {
+    public function getContents(): string {
        return substr($this->data, 0, $this->getPayloadStartingByte() + $this->getPayloadLength());
    }

-    public function __toString() {
+    public function __toString(): string {
        $payload = (string)substr($this->data, $this->getPayloadStartingByte(), $this->getPayloadLength());

        if ($this->isMasked()) {
@ -463,7 +455,7 @@ class Frame implements FrameInterface {
     * This method will take the extra bytes off the end and return them
     * @return string
     */
-    public function extractOverflow() {
+    public function extractOverflow(): string {
        if ($this->isCoalesced()) {
            $endPoint  = $this->getPayloadLength();
            $endPoint += $this->getPayloadStartingByte();
--- a/src/Messaging/FrameInterface.php
+++ b/src/Messaging/FrameInterface.php
@ -6,33 +6,33 @@ interface FrameInterface extends DataInterface {
     * Add incoming data to the frame from peer
     * @param string
     */
-    function addBuffer($buf);
+    public function addBuffer(string $buf): void;

    /**
     * Is this the final frame in a fragmented message?
     * @return bool
     */
-    function isFinal();
+    public function isFinal(): bool;

    /**
     * Is the payload masked?
     * @return bool
     */
-    function isMasked();
+    public function isMasked(): bool;

    /**
     * @return int
     */
-    function getOpcode();
+    public function getOpcode(): int;

    /**
     * @return int
     */
-    //function getReceivedPayloadLength();
+    //public function getReceivedPayloadLength(): int;

    /**
     * 32-big string
     * @return string
     */
-    function getMaskingKey();
+    public function getMaskingKey(): string;
 }
--- a/src/Messaging/Message.php
+++ b/src/Messaging/Message.php
@ -2,53 +2,43 @@
 namespace Ratchet\RFC6455\Messaging;

 class Message implements \IteratorAggregate, MessageInterface {
-    /**
-     * @var \SplDoublyLinkedList
-     */
-    private $_frames;
+    private \SplDoublyLinkedList $_frames;

-    /**
-     * @var int
-     */
-    private $len;
+    private int $len;

-    #[\ReturnTypeWillChange]
    public function __construct() {
        $this->_frames = new \SplDoublyLinkedList;
        $this->len = 0;
    }

-    #[\ReturnTypeWillChange]
-    public function getIterator() {
+    public function getIterator(): \Traversable {
        return $this->_frames;
    }

    /**
     * {@inheritdoc}
     */
-    #[\ReturnTypeWillChange]
-    public function count() {
+    public function count(): int {
        return count($this->_frames);
    }

    /**
     * {@inheritdoc}
     */
-    #[\ReturnTypeWillChange]
-    public function isCoalesced() {
+    public function isCoalesced(): bool {
        if (count($this->_frames) == 0) {
            return false;
        }

        $last = $this->_frames->top();

-        return ($last->isCoalesced() && $last->isFinal());
+        return $last->isCoalesced() && $last->isFinal();
    }

    /**
     * {@inheritdoc}
     */
-    public function addFrame(FrameInterface $fragment) {
+    public function addFrame(FrameInterface $fragment): MessageInterface {
        $this->len += $fragment->getPayloadLength();
        $this->_frames->push($fragment);

@ -58,7 +48,7 @@ class Message implements \IteratorAggregate, MessageInterface {
    /**
     * {@inheritdoc}
     */
-    public function getOpcode() {
+    public function getOpcode(): int {
        if (count($this->_frames) == 0) {
            throw new \UnderflowException('No frames have been added to this message');
        }
@ -69,14 +59,14 @@ class Message implements \IteratorAggregate, MessageInterface {
    /**
     * {@inheritdoc}
     */
-    public function getPayloadLength() {
+    public function getPayloadLength(): int {
        return $this->len;
    }

    /**
     * {@inheritdoc}
     */
-    public function getPayload() {
+    public function getPayload(): string {
        if (!$this->isCoalesced()) {
            throw new \UnderflowException('Message has not been put back together yet');
        }
@ -87,7 +77,7 @@ class Message implements \IteratorAggregate, MessageInterface {
    /**
     * {@inheritdoc}
     */
-    public function getContents() {
+    public function getContents(): string {
        if (!$this->isCoalesced()) {
            throw new \UnderflowException("Message has not been put back together yet");
        }
@ -101,7 +91,7 @@ class Message implements \IteratorAggregate, MessageInterface {
        return $buffer;
    }

-    public function __toString() {
+    public function __toString(): string {
        $buffer = '';

        foreach ($this->_frames as $frame) {
@ -114,7 +104,7 @@ class Message implements \IteratorAggregate, MessageInterface {
    /**
     * @return boolean
     */
-    public function isBinary() {
+    public function isBinary(): bool {
        if ($this->_frames->isEmpty()) {
            throw new \UnderflowException('Not enough data has been received to determine if message is binary');
        }
@ -125,7 +115,7 @@ class Message implements \IteratorAggregate, MessageInterface {
    /**
     * @return boolean
     */
-    public function getRsv1() {
+    public function getRsv1(): bool {
        if ($this->_frames->isEmpty()) {
            return false;
            //throw new \UnderflowException('Not enough data has been received to determine if message is binary');
--- a/src/Messaging/MessageBuffer.php
+++ b/src/Messaging/MessageBuffer.php
@ -4,25 +4,16 @@ namespace Ratchet\RFC6455\Messaging;
 use Ratchet\RFC6455\Handshake\PermessageDeflateOptions;

 class MessageBuffer {
-    /**
-     * @var \Ratchet\RFC6455\Messaging\CloseFrameChecker
-     */
-    private $closeFrameChecker;
+    private CloseFrameChecker $closeFrameChecker;

    /**
     * @var callable
     */
    private $exceptionFactory;

-    /**
-     * @var \Ratchet\RFC6455\Messaging\Message
-     */
-    private $messageBuffer;
+    private ?MessageInterface $messageBuffer = null;

-    /**
-     * @var \Ratchet\RFC6455\Messaging\Frame
-     */
-    private $frameBuffer;
+    private ?FrameInterface $frameBuffer = null;

    /**
     * @var callable
@ -34,71 +25,55 @@ class MessageBuffer {
     */
    private $onControl;

-    /**
-     * @var bool
-     */
-    private $checkForMask;
+    private bool $checkForMask;

    /**
     * @var callable
     */
    private $sender;

-    /**
-     * @var string
-     */
-    private $leftovers;
+    private string $leftovers = '';
+
+    private int $streamingMessageOpCode = -1;
+
+    private PermessageDeflateOptions $permessageDeflateOptions;
+
+    private bool $deflateEnabled;
+
+    private int $maxMessagePayloadSize;
+
+    private int $maxFramePayloadSize;
+
+    private bool $compressedMessage = false;

    /**
-     * @var int
+     * @var resource|bool|null
     */
-    private $streamingMessageOpCode = -1;
+    private $inflator = null;

    /**
-     * @var PermessageDeflateOptions
+     * @var resource|bool|null
     */
-    private $permessageDeflateOptions;
+    private $deflator = null;

-    /**
-     * @var bool
-     */
-    private $deflateEnabled = false;
-
-    /**
-     * @var int
-     */
-    private $maxMessagePayloadSize;
-
-    /**
-     * @var int
-     */
-    private $maxFramePayloadSize;
-
-    /**
-     * @var bool
-     */
-    private $compressedMessage;
-
-    function __construct(
+    public function __construct(
        CloseFrameChecker $frameChecker,
        callable $onMessage,
-        callable $onControl = null,
-        $expectMask = true,
-        $exceptionFactory = null,
-        $maxMessagePayloadSize = null, // null for default - zero for no limit
-        $maxFramePayloadSize = null,   // null for default - zero for no limit
-        callable $sender = null,
-        PermessageDeflateOptions $permessageDeflateOptions = null
+        ?callable $onControl = null,
+        bool $expectMask = true,
+        ?callable $exceptionFactory = null,
+        ?int $maxMessagePayloadSize = null, // null for default - zero for no limit
+        ?int $maxFramePayloadSize = null,   // null for default - zero for no limit
+        ?callable $sender = null,
+        ?PermessageDeflateOptions $permessageDeflateOptions = null
    ) {
        $this->closeFrameChecker = $frameChecker;
-        $this->checkForMask = (bool)$expectMask;
+        $this->checkForMask = $expectMask;

-        $this->exceptionFactory ?: $exceptionFactory = function($msg) {
-            return new \UnderflowException($msg);
-        };
+        $this->exceptionFactory = $exceptionFactory ?: static fn (string $msg) => new \UnderflowException($msg);

        $this->onMessage = $onMessage;
-        $this->onControl = $onControl ?: function() {};
+        $this->onControl = $onControl ?: static function (): void {};

        $this->sender = $sender;

@ -110,10 +85,6 @@ class MessageBuffer {
            throw new \InvalidArgumentException('sender must be set when deflate is enabled');
        }

-        $this->compressedMessage = false;
-
-        $this->leftovers = '';
-
        $memory_limit_bytes = static::getMemoryLimit();

        if ($maxMessagePayloadSize === null) {
@ -123,18 +94,18 @@ class MessageBuffer {
            $maxFramePayloadSize = (int)($memory_limit_bytes / 4);
        }

-        if (!is_int($maxFramePayloadSize) || $maxFramePayloadSize > 0x7FFFFFFFFFFFFFFF || $maxFramePayloadSize < 0) { // this should be interesting on non-64 bit systems
+        if ($maxFramePayloadSize > 0x7FFFFFFFFFFFFFFF || $maxFramePayloadSize < 0) { // this should be interesting on non-64 bit systems
            throw new \InvalidArgumentException($maxFramePayloadSize . ' is not a valid maxFramePayloadSize');
        }
        $this->maxFramePayloadSize = $maxFramePayloadSize;

-        if (!is_int($maxMessagePayloadSize) || $maxMessagePayloadSize > 0x7FFFFFFFFFFFFFFF || $maxMessagePayloadSize < 0) {
+        if ($maxMessagePayloadSize > 0x7FFFFFFFFFFFFFFF || $maxMessagePayloadSize < 0) {
            throw new \InvalidArgumentException($maxMessagePayloadSize . 'is not a valid maxMessagePayloadSize');
        }
        $this->maxMessagePayloadSize = $maxMessagePayloadSize;
    }

-    public function onData($data) {
+    public function onData(string $data): void {
        $data = $this->leftovers . $data;
        $dataLen = strlen($data);

@ -214,9 +185,9 @@ class MessageBuffer {

    /**
     * @param string $data
-     * @return null
+     * @return void
     */
-    private function processData($data) {
+    private function processData(string $data): void {
        $this->messageBuffer ?: $this->messageBuffer = $this->newMessage();
        $this->frameBuffer   ?: $this->frameBuffer   = $this->newFrame();

@ -235,7 +206,7 @@ class MessageBuffer {
            $onControl($this->frameBuffer, $this);

            if (Frame::OP_CLOSE === $opcode) {
-                return '';
+                return;
            }
        } else {
            if ($this->messageBuffer->count() === 0 && $this->frameBuffer->getRsv1()) {
@ -273,10 +244,10 @@ class MessageBuffer {

    /**
     * Check a frame to be added to the current message buffer
-     * @param \Ratchet\RFC6455\Messaging\FrameInterface|FrameInterface $frame
-     * @return \Ratchet\RFC6455\Messaging\FrameInterface|FrameInterface
+     * @param FrameInterface $frame
+     * @return FrameInterface
     */
-    public function frameCheck(FrameInterface $frame) {
+    public function frameCheck(FrameInterface $frame): FrameInterface {
        if ((false !== $frame->getRsv1() && !$this->deflateEnabled) ||
            false !== $frame->getRsv2() ||
            false !== $frame->getRsv3()
@ -323,13 +294,11 @@ class MessageBuffer {
                    }

                    return $frame;
-                    break;
                case Frame::OP_PING:
                case Frame::OP_PONG:
                    break;
                default:
                    return $this->newCloseFrame(Frame::CLOSE_PROTOCOL, 'Ratchet detected an invalid OP code');
-                    break;
            }

            return $frame;
@ -348,7 +317,7 @@ class MessageBuffer {

    /**
     * Determine if a message is valid
-     * @param \Ratchet\RFC6455\Messaging\MessageInterface
+     * @param MessageInterface
     * @return bool|int true if valid - false if incomplete - int of recommended close code
     */
    public function checkMessage(MessageInterface $message) {
@ -361,7 +330,7 @@ class MessageBuffer {
        return true;
    }

-    private function checkUtf8($string) {
+    private function checkUtf8(string $string): bool {
        if (extension_loaded('mbstring')) {
            return mb_check_encoding($string, 'UTF-8');
        }
@ -370,27 +339,27 @@ class MessageBuffer {
    }

    /**
-     * @return \Ratchet\RFC6455\Messaging\MessageInterface
+     * @return MessageInterface
     */
-    public function newMessage() {
+    public function newMessage(): MessageInterface {
        return new Message;
    }

    /**
     * @param string|null $payload
-     * @param bool|null   $final
-     * @param int|null    $opcode
-     * @return \Ratchet\RFC6455\Messaging\FrameInterface
+     * @param bool        $final
+     * @param int         $opcode
+     * @return FrameInterface
     */
-    public function newFrame($payload = null, $final = null, $opcode = null) {
+    public function newFrame(?string $payload = null, bool $final = true, int $opcode = Frame::OP_TEXT): FrameInterface {
        return new Frame($payload, $final, $opcode, $this->exceptionFactory);
    }

-    public function newCloseFrame($code, $reason = '') {
+    public function newCloseFrame(int $code, string $reason = ''): FrameInterface {
        return $this->newFrame(pack('n', $code) . $reason, true, Frame::OP_CLOSE);
    }

-    public function sendFrame(Frame $frame) {
+    public function sendFrame(FrameInterface $frame): void {
        if ($this->sender === null) {
            throw new \Exception('To send frames using the MessageBuffer, sender must be set.');
        }
@ -408,7 +377,7 @@ class MessageBuffer {
        $sender($frame->getContents());
    }

-    public function sendMessage($messagePayload, $final = true, $isBinary = false) {
+    public function sendMessage(string $messagePayload, bool $final = true, bool $isBinary = false): void {
        $opCode = $isBinary ? Frame::OP_BINARY : Frame::OP_TEXT;
        if ($this->streamingMessageOpCode === -1) {
            $this->streamingMessageOpCode = $opCode;
@ -431,29 +400,27 @@ class MessageBuffer {
        }
    }

-    private $inflator;
-
-    private function getDeflateNoContextTakeover() {
+    private function getDeflateNoContextTakeover(): ?bool {
        return $this->checkForMask ?
            $this->permessageDeflateOptions->getServerNoContextTakeover() :
            $this->permessageDeflateOptions->getClientNoContextTakeover();
    }

-    private function getDeflateWindowBits() {
+    private function getDeflateWindowBits(): int {
        return $this->checkForMask ? $this->permessageDeflateOptions->getServerMaxWindowBits() : $this->permessageDeflateOptions->getClientMaxWindowBits();
    }

-    private function getInflateNoContextTakeover() {
+    private function getInflateNoContextTakeover(): ?bool {
        return $this->checkForMask ?
            $this->permessageDeflateOptions->getClientNoContextTakeover() :
            $this->permessageDeflateOptions->getServerNoContextTakeover();
    }

-    private function getInflateWindowBits() {
+    private function getInflateWindowBits(): int {
        return $this->checkForMask ? $this->permessageDeflateOptions->getClientMaxWindowBits() : $this->permessageDeflateOptions->getServerMaxWindowBits();
    }

-    private function inflateFrame(Frame $frame) {
+    private function inflateFrame(FrameInterface $frame): Frame {
        if ($this->inflator === null) {
            $this->inflator = inflate_init(
                ZLIB_ENCODING_RAW,
@ -480,16 +447,14 @@ class MessageBuffer {
        );
    }

-    private $deflator;
-
-    private function deflateFrame(Frame $frame)
+    private function deflateFrame(FrameInterface $frame): FrameInterface
    {
        if ($frame->getRsv1()) {
            return $frame; // frame is already deflated
        }

        if ($this->deflator === null) {
-            $bits = (int)$this->getDeflateWindowBits();
+            $bits = $this->getDeflateWindowBits();
            if ($bits === 8) {
                $bits = 9;
            }
@ -549,7 +514,7 @@ class MessageBuffer {
     * @param null|string $memory_limit
     * @return int
     */
-    private static function getMemoryLimit($memory_limit = null) {
+    private static function getMemoryLimit(?string $memory_limit = null): int {
        $memory_limit = $memory_limit === null ? \trim(\ini_get('memory_limit')) : $memory_limit;
        $memory_limit_bytes = 0;
        if ($memory_limit !== '') {
--- a/src/Messaging/MessageInterface.php
+++ b/src/Messaging/MessageInterface.php
@ -6,15 +6,15 @@ interface MessageInterface extends DataInterface, \Traversable, \Countable {
     * @param FrameInterface $fragment
     * @return MessageInterface
     */
-    function addFrame(FrameInterface $fragment);
+    public function addFrame(FrameInterface $fragment): self;

    /**
     * @return int
     */
-    function getOpcode();
+    public function getOpcode(): int;

    /**
     * @return bool
     */
-    function isBinary();
+    public function isBinary(): bool;
 }
--- a/tests/AbResultsTest.php
+++ b/tests/AbResultsTest.php
@ -3,10 +3,13 @@
 namespace Ratchet\RFC6455\Test;
 use PHPUnit\Framework\TestCase;

+/**
+ * @coversNothing
+ */
 class AbResultsTest extends TestCase {
-    private function verifyAutobahnResults($fileName) {
+    private function verifyAutobahnResults(string $fileName): void {
        if (!file_exists($fileName)) {
-            return $this->markTestSkipped('Autobahn TestSuite results not found');
+            $this->markTestSkipped('Autobahn TestSuite results not found');
        }

        $resultsJson = file_get_contents($fileName);
@ -22,11 +25,11 @@ class AbResultsTest extends TestCase {
        }
    }

-    public function testAutobahnClientResults() {
+    public function testAutobahnClientResults(): void {
        $this->verifyAutobahnResults(__DIR__ . '/ab/reports/clients/index.json');
    }

-    public function testAutobahnServerResults() {
+    public function testAutobahnServerResults(): void {
        $this->verifyAutobahnResults(__DIR__ . '/ab/reports/servers/index.json');
    }
 }
--- a/tests/ab/clientRunner.php
+++ b/tests/ab/clientRunner.php
@ -4,18 +4,21 @@ use GuzzleHttp\Psr7\Message;
 use GuzzleHttp\Psr7\Uri;
 use Ratchet\RFC6455\Handshake\InvalidPermessageDeflateOptionsException;
 use Ratchet\RFC6455\Handshake\PermessageDeflateOptions;
+use Ratchet\RFC6455\Messaging\FrameInterface;
 use Ratchet\RFC6455\Messaging\MessageBuffer;
 use Ratchet\RFC6455\Handshake\ClientNegotiator;
 use Ratchet\RFC6455\Messaging\CloseFrameChecker;
 use Ratchet\RFC6455\Messaging\MessageInterface;
 use React\Promise\Deferred;
 use Ratchet\RFC6455\Messaging\Frame;
+use React\Promise\PromiseInterface;
+use GuzzleHttp\Psr7\HttpFactory;
 use React\Socket\ConnectionInterface;
 use React\Socket\Connector;

 require __DIR__ . '/../bootstrap.php';

-define('AGENT', 'RatchetRFC/0.3');
+define('AGENT', 'RatchetRFC/0.4');

 $testServer = $argc > 1 ? $argv[1] : "127.0.0.1";

@ -23,23 +26,21 @@ $loop = React\EventLoop\Factory::create();

 $connector = new Connector($loop);

-function echoStreamerFactory($conn, $permessageDeflateOptions = null)
+function echoStreamerFactory(ConnectionInterface $conn, ?PermessageDeflateOptions $permessageDeflateOptions = null): MessageBuffer
 {
    $permessageDeflateOptions = $permessageDeflateOptions ?: PermessageDeflateOptions::createDisabled();

-    return new \Ratchet\RFC6455\Messaging\MessageBuffer(
-        new \Ratchet\RFC6455\Messaging\CloseFrameChecker,
-        function (\Ratchet\RFC6455\Messaging\MessageInterface $msg, MessageBuffer $messageBuffer) use ($conn) {
+    return new MessageBuffer(
+        new CloseFrameChecker,
+        static function (MessageInterface $msg, MessageBuffer $messageBuffer) use ($conn): void {
            $messageBuffer->sendMessage($msg->getPayload(), true, $msg->isBinary());
        },
-        function (\Ratchet\RFC6455\Messaging\FrameInterface $frame, MessageBuffer $messageBuffer) use ($conn) {
+        static function (FrameInterface $frame, MessageBuffer $messageBuffer) use ($conn) {
            switch ($frame->getOpcode()) {
                case Frame::OP_PING:
                    return $conn->write((new Frame($frame->getPayload(), true, Frame::OP_PONG))->maskPayload()->getContents());
-                    break;
                case Frame::OP_CLOSE:
                    return $conn->end((new Frame($frame->getPayload(), true, Frame::OP_CLOSE))->maskPayload()->getContents());
-                    break;
            }
        },
        false,
@ -51,14 +52,14 @@ function echoStreamerFactory($conn, $permessageDeflateOptions = null)
    );
 }

-function getTestCases() {
+function getTestCases(): PromiseInterface {
    global $testServer;
    global $connector;

    $deferred = new Deferred();

-    $connector->connect($testServer . ':9002')->then(function (ConnectionInterface $connection) use ($deferred, $testServer) {
-        $cn = new ClientNegotiator();
+    $connector->connect($testServer . ':9002')->then(static function (ConnectionInterface $connection) use ($deferred, $testServer): void {
+        $cn = new ClientNegotiator(new HttpFactory());
        $cnRequest = $cn->generateRequest(new Uri('ws://' . $testServer . ':9002/getCaseCount'));

        $rawResponse = "";
@ -67,7 +68,7 @@ function getTestCases() {
        /** @var MessageBuffer $ms */
        $ms = null;

-        $connection->on('data', function ($data) use ($connection, &$rawResponse, &$response, &$ms, $cn, $deferred, &$context, $cnRequest) {
+        $connection->on('data', static function ($data) use ($connection, &$rawResponse, &$response, &$ms, $cn, $deferred, &$context, $cnRequest): void {
            if ($response === null) {
                $rawResponse .= $data;
                $pos = strpos($rawResponse, "\r\n\r\n");
@ -82,7 +83,7 @@ function getTestCases() {
                    } else {
                        $ms = new MessageBuffer(
                            new CloseFrameChecker,
-                            function (MessageInterface $msg) use ($deferred, $connection) {
+                            static function (MessageInterface $msg) use ($deferred, $connection): void {
                                $deferred->resolve($msg->getPayload());
                                $connection->close();
                            },
@ -91,7 +92,7 @@ function getTestCases() {
                            null,
                            null,
                            null,
-                            function () {}
+                            static function (): void {}
                        );
                    }
                }
@ -109,10 +110,11 @@ function getTestCases() {
    return $deferred->promise();
 }

-$cn = new \Ratchet\RFC6455\Handshake\ClientNegotiator(
+$cn = new ClientNegotiator(
+    new HttpFactory(),
    PermessageDeflateOptions::permessageDeflateSupported() ? PermessageDeflateOptions::createEnabled() : null);

-function runTest($case)
+function runTest(int $case)
 {
    global $connector;
    global $testServer;
@ -122,8 +124,9 @@ function runTest($case)

    $deferred = new Deferred();

-    $connector->connect($testServer . ':9002')->then(function (ConnectionInterface $connection) use ($deferred, $casePath, $case, $testServer) {
+    $connector->connect($testServer . ':9002')->then(static function (ConnectionInterface $connection) use ($deferred, $casePath, $case, $testServer): void {
        $cn = new ClientNegotiator(
+            new HttpFactory(),
            PermessageDeflateOptions::permessageDeflateSupported() ? PermessageDeflateOptions::createEnabled() : null);
        $cnRequest = $cn->generateRequest(new Uri('ws://' . $testServer . ':9002' . $casePath));

@ -132,7 +135,7 @@ function runTest($case)

        $ms = null;

-        $connection->on('data', function ($data) use ($connection, &$rawResponse, &$response, &$ms, $cn, $deferred, &$context, $cnRequest) {
+        $connection->on('data', static function ($data) use ($connection, &$rawResponse, &$response, &$ms, $cn, $deferred, &$context, $cnRequest): void {
            if ($response === null) {
                $rawResponse .= $data;
                $pos = strpos($rawResponse, "\r\n\r\n");
@ -165,8 +168,8 @@ function runTest($case)
            }
        });

-        $connection->on('close', function () use ($deferred) {
-            $deferred->resolve();
+        $connection->on('close', static function () use ($deferred): void {
+            $deferred->resolve(null);
        });

        $connection->write(Message::toString($cnRequest));
@ -175,17 +178,17 @@ function runTest($case)
    return $deferred->promise();
 }

-function createReport() {
+function createReport(): PromiseInterface {
    global $connector;
    global $testServer;

    $deferred = new Deferred();

-    $connector->connect($testServer . ':9002')->then(function (ConnectionInterface $connection) use ($deferred, $testServer) {
+    $connector->connect($testServer . ':9002')->then(static function (ConnectionInterface $connection) use ($deferred, $testServer): void {
        // $reportPath = "/updateReports?agent=" . AGENT . "&shutdownOnComplete=true";
        // we will stop it using docker now instead of just shutting down
        $reportPath = "/updateReports?agent=" . AGENT;
-        $cn = new ClientNegotiator();
+        $cn = new ClientNegotiator(new HttpFactory());
        $cnRequest = $cn->generateRequest(new Uri('ws://' . $testServer . ':9002' . $reportPath));

        $rawResponse = "";
@ -194,7 +197,7 @@ function createReport() {
        /** @var MessageBuffer $ms */
        $ms = null;

-        $connection->on('data', function ($data) use ($connection, &$rawResponse, &$response, &$ms, $cn, $deferred, &$context, $cnRequest) {
+        $connection->on('data', static function ($data) use ($connection, &$rawResponse, &$response, &$ms, $cn, $deferred, &$context, $cnRequest): void {
            if ($response === null) {
                $rawResponse .= $data;
                $pos = strpos($rawResponse, "\r\n\r\n");
@ -209,7 +212,7 @@ function createReport() {
                    } else {
                        $ms = new MessageBuffer(
                            new CloseFrameChecker,
-                            function (MessageInterface $msg) use ($deferred, $connection) {
+                            static function (MessageInterface $msg) use ($deferred, $connection): void {
                                $deferred->resolve($msg->getPayload());
                                $connection->close();
                            },
@ -218,7 +221,7 @@ function createReport() {
                            null,
                            null,
                            null,
-                            function () {}
+                            static function (): void {}
                        );
                    }
                }
@ -242,16 +245,16 @@ $testPromises = [];
 getTestCases()->then(function ($count) use ($loop) {
    $allDeferred = new Deferred();

-    $runNextCase = function () use (&$i, &$runNextCase, $count, $allDeferred) {
+    $runNextCase = static function () use (&$i, &$runNextCase, $count, $allDeferred): void {
        $i++;
        if ($i > $count) {
-            $allDeferred->resolve();
+            $allDeferred->resolve(null);
            return;
        }
        echo "Running test $i/$count...";
        $startTime = microtime(true);
        runTest($i)
-            ->then(function () use ($startTime) {
+            ->then(static function () use ($startTime): void {
                echo " completed " . round((microtime(true) - $startTime) * 1000) . " ms\n";
            })
            ->then($runNextCase);
@ -260,7 +263,7 @@ getTestCases()->then(function ($count) use ($loop) {
    $i = 0;
    $runNextCase();

-    $allDeferred->promise()->then(function () {
+    $allDeferred->promise()->then(static function (): void {
        createReport();
    });
 });
--- a/tests/ab/fuzzingclient.json
+++ b/tests/ab/fuzzingclient.json
@ -4,7 +4,7 @@
    }
  , "outdir": "/reports/servers"
  , "servers": [{
-        "agent": "RatchetRFC/0.3"
+        "agent": "RatchetRFC/0.4"
      , "url": "ws://host.ratchet.internal:9001"
      , "options": {"version": 18}
    }]
--- a/tests/ab/fuzzingclient_skip_deflate.json
+++ b/tests/ab/fuzzingclient_skip_deflate.json
@ -4,7 +4,7 @@
    }
  , "outdir": "/reports/servers"
  , "servers": [{
-        "agent": "RatchetRFC/0.3"
+        "agent": "RatchetRFC/0.4"
      , "url": "ws://host.ratchet.internal:9001"
      , "options": {"version": 18}
    }]
--- a/tests/ab/run_ab_tests.sh
+++ b/tests/ab/run_ab_tests.sh
--- a/tests/ab/startServer.php
+++ b/tests/ab/startServer.php
@ -3,10 +3,14 @@
 use GuzzleHttp\Psr7\Message;
 use GuzzleHttp\Psr7\Response;
 use Ratchet\RFC6455\Handshake\PermessageDeflateOptions;
+use Ratchet\RFC6455\Handshake\RequestVerifier;
+use Ratchet\RFC6455\Handshake\ServerNegotiator;
+use Ratchet\RFC6455\Messaging\CloseFrameChecker;
 use Ratchet\RFC6455\Messaging\MessageBuffer;
 use Ratchet\RFC6455\Messaging\MessageInterface;
 use Ratchet\RFC6455\Messaging\FrameInterface;
 use Ratchet\RFC6455\Messaging\Frame;
+use GuzzleHttp\Psr7\HttpFactory;

 require_once __DIR__ . "/../bootstrap.php";

@ -14,17 +18,22 @@ $loop   = \React\EventLoop\Factory::create();

 $socket = new \React\Socket\Server('0.0.0.0:9001', $loop);

-$closeFrameChecker = new \Ratchet\RFC6455\Messaging\CloseFrameChecker;
-$negotiator = new \Ratchet\RFC6455\Handshake\ServerNegotiator(new \Ratchet\RFC6455\Handshake\RequestVerifier, PermessageDeflateOptions::permessageDeflateSupported());
+$closeFrameChecker = new CloseFrameChecker;
+
+$negotiator = new ServerNegotiator(
+    new RequestVerifier,
+    new HttpFactory(),
+    PermessageDeflateOptions::permessageDeflateSupported()
+);

 $uException = new \UnderflowException;


-$socket->on('connection', function (React\Socket\ConnectionInterface $connection) use ($negotiator, $closeFrameChecker, $uException, $socket) {
+$socket->on('connection', static function (React\Socket\ConnectionInterface $connection) use ($negotiator, $closeFrameChecker, $uException, $socket): void {
    $headerComplete = false;
    $buffer = '';
    $parser = null;
-    $connection->on('data', function ($data) use ($connection, &$parser, &$headerComplete, &$buffer, $negotiator, $closeFrameChecker, $uException, $socket) {
+    $connection->on('data', static function ($data) use ($connection, &$parser, &$headerComplete, &$buffer, $negotiator, $closeFrameChecker, $uException, $socket): void {
        if ($headerComplete) {
            $parser->onData($data);
            return;
@ -58,10 +67,10 @@ $socket->on('connection', function (React\Socket\ConnectionInterface $connection
        // we support any valid permessage deflate
        $deflateOptions = PermessageDeflateOptions::fromRequestOrResponse($psrRequest)[0];

-        $parser = new \Ratchet\RFC6455\Messaging\MessageBuffer($closeFrameChecker,
-            function (MessageInterface $message, MessageBuffer $messageBuffer) {
+        $parser = new MessageBuffer($closeFrameChecker,
+            static function (MessageInterface $message, MessageBuffer $messageBuffer): void {
                $messageBuffer->sendMessage($message->getPayload(), true, $message->isBinary());
-            }, function (FrameInterface $frame) use ($connection, &$parser) {
+            }, static function (FrameInterface $frame) use ($connection, &$parser): void {
                switch ($frame->getOpCode()) {
                    case Frame::OP_CLOSE:
                        $connection->end($frame->getContents());
@ -70,9 +79,7 @@ $socket->on('connection', function (React\Socket\ConnectionInterface $connection
                        $connection->write($parser->newFrame($frame->getPayload(), true, Frame::OP_PONG)->getContents());
                        break;
                }
-            }, true, function () use ($uException) {
-                return $uException;
-            },
+            }, true, static fn (): \Exception => $uException,
            null,
            null,
           [$connection, 'write'],
--- a/tests/unit/Handshake/PermessageDeflateOptionsTest.php
+++ b/tests/unit/Handshake/PermessageDeflateOptionsTest.php
@ -5,9 +5,12 @@ namespace Ratchet\RFC6455\Test\Unit\Handshake;
 use Ratchet\RFC6455\Handshake\PermessageDeflateOptions;
 use PHPUnit\Framework\TestCase;

+/**
+ * @covers Ratchet\RFC6455\Handshake\PermessageDeflateOptions
+ */
 class PermessageDeflateOptionsTest extends TestCase
 {
-    public static function versionSupportProvider() {
+    public static function versionSupportProvider(): array {
        return [
            ['7.0.17', false],
            ['7.0.18', true],
@ -24,7 +27,7 @@ class PermessageDeflateOptionsTest extends TestCase
     * @requires function deflate_init
     * @dataProvider versionSupportProvider
     */
-    public function testVersionSupport($version, $supported) {
+    public function testVersionSupport(string $version, bool $supported): void {
        $this->assertEquals($supported, PermessageDeflateOptions::permessageDeflateSupported($version));
    }
 }
--- a/tests/unit/Handshake/RequestVerifierTest.php
+++ b/tests/unit/Handshake/RequestVerifierTest.php
@ -14,11 +14,11 @@ class RequestVerifierTest extends TestCase {
     */
    protected $_v;

-    public function setUp() {
+    protected function setUp(): void {
        $this->_v = new RequestVerifier();
    }

-    public static function methodProvider() {
+    public static function methodProvider(): array {
        return array(
            array(true,  'GET'),
            array(true,  'get'),
@ -32,11 +32,11 @@ class RequestVerifierTest extends TestCase {
    /**
     * @dataProvider methodProvider
     */
-    public function testMethodMustBeGet($result, $in) {
+    public function testMethodMustBeGet(bool $result, string $in): void {
        $this->assertEquals($result, $this->_v->verifyMethod($in));
    }

-    public static function httpVersionProvider() {
+    public static function httpVersionProvider(): array {
        return array(
            array(true,  1.1),
            array(true,  '1.1'),
@ -56,11 +56,11 @@ class RequestVerifierTest extends TestCase {
    /**
     * @dataProvider httpVersionProvider
     */
-    public function testHttpVersionIsAtLeast1Point1($expected, $in) {
+    public function testHttpVersionIsAtLeast1Point1(bool $expected, $in): void {
        $this->assertEquals($expected, $this->_v->verifyHTTPVersion($in));
    }

-    public static function uRIProvider() {
+    public static function uRIProvider(): array {
        return array(
            array(true, '/chat'),
            array(true, '/hello/world?key=val'),
@ -74,11 +74,11 @@ class RequestVerifierTest extends TestCase {
    /**
     * @dataProvider URIProvider
     */
-    public function testRequestUri($expected, $in) {
+    public function testRequestUri(bool $expected, string $in): void {
        $this->assertEquals($expected, $this->_v->verifyRequestURI($in));
    }

-    public static function hostProvider() {
+    public static function hostProvider(): array {
        return array(
            array(true, ['server.example.com']),
            array(false, [])
@ -88,11 +88,11 @@ class RequestVerifierTest extends TestCase {
    /**
     * @dataProvider HostProvider
     */
-    public function testVerifyHostIsSet($expected, $in) {
+    public function testVerifyHostIsSet(bool $expected, array $in): void {
        $this->assertEquals($expected, $this->_v->verifyHost($in));
    }

-    public static function upgradeProvider() {
+    public static function upgradeProvider(): array {
        return array(
            array(true,  ['websocket']),
            array(true,  ['Websocket']),
@ -105,11 +105,11 @@ class RequestVerifierTest extends TestCase {
    /**
     * @dataProvider upgradeProvider
     */
-    public function testVerifyUpgradeIsWebSocket($expected, $val) {
+    public function testVerifyUpgradeIsWebSocket(bool $expected, array $val): void {
        $this->assertEquals($expected, $this->_v->verifyUpgradeRequest($val));
    }

-    public static function connectionProvider() {
+    public static function connectionProvider(): array {
        return array(
            array(true,  ['Upgrade']),
            array(true,  ['upgrade']),
@ -129,11 +129,11 @@ class RequestVerifierTest extends TestCase {
    /**
     * @dataProvider connectionProvider
     */
-    public function testConnectionHeaderVerification($expected, $val) {
+    public function testConnectionHeaderVerification(bool $expected, array $val): void {
        $this->assertEquals($expected, $this->_v->verifyConnection($val));
    }

-    public static function keyProvider() {
+    public static function keyProvider(): array {
        return array(
            array(true,  ['hkfa1L7uwN6DCo4IS3iWAw==']),
            array(true,  ['765vVoQpKSGJwPzJIMM2GA==']),
@ -154,11 +154,11 @@ class RequestVerifierTest extends TestCase {
    /**
     * @dataProvider keyProvider
     */
-    public function testKeyIsBase64Encoded16BitNonce($expected, $val) {
+    public function testKeyIsBase64Encoded16BitNonce(bool $expected, array $val): void {
        $this->assertEquals($expected, $this->_v->verifyKey($val));
    }

-    public static function versionProvider() {
+    public static function versionProvider(): array {
        return array(
            array(true,  [13]),
            array(true,  ['13']),
@ -174,7 +174,7 @@ class RequestVerifierTest extends TestCase {
    /**
     * @dataProvider versionProvider
     */
-    public function testVersionEquals13($expected, $in) {
+    public function testVersionEquals13(bool $expected, array $in): void {
        $this->assertEquals($expected, $this->_v->verifyVersion($in));
    }
 }
--- a/tests/unit/Handshake/ResponseVerifierTest.php
+++ b/tests/unit/Handshake/ResponseVerifierTest.php
@ -14,11 +14,11 @@ class ResponseVerifierTest extends TestCase {
     */
    protected $_v;

-    public function setUp() {
+    protected function setUp(): void {
        $this->_v = new ResponseVerifier;
    }

-    public static function subProtocolsProvider() {
+    public static function subProtocolsProvider(): array {
        return [
            [true,  ['a'], ['a']]
          , [true,  ['c', 'd', 'a'], ['a']]
@ -33,7 +33,7 @@ class ResponseVerifierTest extends TestCase {
    /**
     * @dataProvider subProtocolsProvider
     */
-    public function testVerifySubProtocol($expected, $request, $response) {
+    public function testVerifySubProtocol(bool $expected, array $request, array $response): void {
        $this->assertEquals($expected, $this->_v->verifySubProtocol($request, $response));
    }
 }
--- a/tests/unit/Handshake/ServerNegotiatorTest.php
+++ b/tests/unit/Handshake/ServerNegotiatorTest.php
@ -3,14 +3,18 @@
 namespace Ratchet\RFC6455\Test\Unit\Handshake;

 use GuzzleHttp\Psr7\Message;
+use GuzzleHttp\Psr7\HttpFactory;
 use Ratchet\RFC6455\Handshake\RequestVerifier;
 use Ratchet\RFC6455\Handshake\ServerNegotiator;
 use PHPUnit\Framework\TestCase;

+/**
+ * @covers Ratchet\RFC6455\Handshake\ServerNegotiator
+ */
 class ServerNegotiatorTest extends TestCase
 {
-    public function testNoUpgradeRequested() {
-        $negotiator = new ServerNegotiator(new RequestVerifier());
+    public function testNoUpgradeRequested(): void {
+        $negotiator = new ServerNegotiator(new RequestVerifier(), new HttpFactory());

        $requestText = 'GET / HTTP/1.1
 Host: 127.0.0.1:6789
@ -37,8 +41,8 @@ Accept-Language: en-US,en;q=0.8
        $this->assertEquals('13', $response->getHeaderLine('Sec-WebSocket-Version'));
    }

-    public function testNoConnectionUpgradeRequested() {
-        $negotiator = new ServerNegotiator(new RequestVerifier());
+    public function testNoConnectionUpgradeRequested(): void {
+        $negotiator = new ServerNegotiator(new RequestVerifier(), new HttpFactory());

        $requestText = 'GET / HTTP/1.1
 Host: 127.0.0.1:6789
@ -63,8 +67,8 @@ Accept-Language: en-US,en;q=0.8
        $this->assertEquals('Connection Upgrade MUST be requested', $response->getReasonPhrase());
    }

-    public function testInvalidSecWebsocketKey() {
-        $negotiator = new ServerNegotiator(new RequestVerifier());
+    public function testInvalidSecWebsocketKey(): void {
+        $negotiator = new ServerNegotiator(new RequestVerifier(), new HttpFactory());

        $requestText = 'GET / HTTP/1.1
 Host: 127.0.0.1:6789
@ -90,8 +94,8 @@ Accept-Language: en-US,en;q=0.8
        $this->assertEquals('Invalid Sec-WebSocket-Key', $response->getReasonPhrase());
    }

-    public function testInvalidSecWebsocketVersion() {
-        $negotiator = new ServerNegotiator(new RequestVerifier());
+    public function testInvalidSecWebsocketVersion(): void {
+        $negotiator = new ServerNegotiator(new RequestVerifier(), new HttpFactory());

        $requestText = 'GET / HTTP/1.1
 Host: 127.0.0.1:6789
@ -120,8 +124,8 @@ Accept-Language: en-US,en;q=0.8
        $this->assertEquals('13', $response->getHeaderLine('Sec-WebSocket-Version'));
    }

-    public function testBadSubprotocolResponse() {
-        $negotiator = new ServerNegotiator(new RequestVerifier());
+    public function testBadSubprotocolResponse(): void {
+        $negotiator = new ServerNegotiator(new RequestVerifier(), new HttpFactory());
        $negotiator->setStrictSubProtocolCheck(true);
        $negotiator->setSupportedSubProtocols([]);

@ -154,8 +158,8 @@ Accept-Language: en-US,en;q=0.8
        $this->assertEquals('13', $response->getHeaderLine('Sec-WebSocket-Version'));
    }

-    public function testNonStrictSubprotocolDoesNotIncludeHeaderWhenNoneAgreedOn() {
-        $negotiator = new ServerNegotiator(new RequestVerifier());
+    public function testNonStrictSubprotocolDoesNotIncludeHeaderWhenNoneAgreedOn(): void {
+        $negotiator = new ServerNegotiator(new RequestVerifier(), new HttpFactory());
        $negotiator->setStrictSubProtocolCheck(false);
        $negotiator->setSupportedSubProtocols(['someproto']);

@ -187,9 +191,9 @@ Accept-Language: en-US,en;q=0.8
        $this->assertFalse($response->hasHeader('Sec-WebSocket-Protocol'));
    }

-    public function testSuggestsAppropriateSubprotocol()
+    public function testSuggestsAppropriateSubprotocol(): void
    {
-        $negotiator = new ServerNegotiator(new RequestVerifier());
+        $negotiator = new ServerNegotiator(new RequestVerifier(), new HttpFactory());
        $negotiator->setStrictSubProtocolCheck(true);
        $negotiator->setSupportedSubProtocols(['someproto']);

--- a/tests/unit/Messaging/FrameTest.php
+++ b/tests/unit/Messaging/FrameTest.php
@ -20,7 +20,7 @@ class FrameTest extends TestCase {

    protected $_packer;

-    public function setUp() {
+    protected function setUp(): void {
        $this->_frame = new Frame;
    }

@ -29,7 +29,7 @@ class FrameTest extends TestCase {
     * @param string of 1's and 0's
     * @return string
     */
-    public static function encode($in) {
+    public static function encode(string $in): string {
        if (strlen($in) > 8) {
            $out = '';
            while (strlen($in) >= 8) {
@ -46,7 +46,7 @@ class FrameTest extends TestCase {
     * param string The UTF8 message
     * param string The WebSocket framed message, then base64_encoded
     */
-    public static function UnframeMessageProvider() {
+    public static function UnframeMessageProvider(): array {
        return array(
            array('Hello World!', 'gYydAIfa1WXrtvIg0LXvbOP7'),
            array('!@#$%^&*()-=_+[]{}\|/.,<>`~', 'gZv+h96r38f9j9vZ+IHWrvOWoayF9oX6gtfRqfKXwOeg'),
@ -58,7 +58,7 @@ class FrameTest extends TestCase {
        );
    }

-    public static function underflowProvider() {
+    public static function underflowProvider(): array {
        return array(
            array('isFinal', ''),
            array('getRsv1', ''),
@ -75,19 +75,9 @@ class FrameTest extends TestCase {

    /**
     * @dataProvider underflowProvider
-     *
-     * @covers Ratchet\RFC6455\Messaging\Frame::isFinal
-     * @covers Ratchet\RFC6455\Messaging\Frame::getRsv1
-     * @covers Ratchet\RFC6455\Messaging\Frame::getRsv2
-     * @covers Ratchet\RFC6455\Messaging\Frame::getRsv3
-     * @covers Ratchet\RFC6455\Messaging\Frame::getOpcode
-     * @covers Ratchet\RFC6455\Messaging\Frame::isMasked
-     * @covers Ratchet\RFC6455\Messaging\Frame::getPayloadLength
-     * @covers Ratchet\RFC6455\Messaging\Frame::getMaskingKey
-     * @covers Ratchet\RFC6455\Messaging\Frame::getPayload
     */
-    public function testUnderflowExceptionFromAllTheMethodsMimickingBuffering($method, $bin) {
-        $this->setExpectedException('\UnderflowException');
+    public function testUnderflowExceptionFromAllTheMethodsMimickingBuffering(string $method, string $bin): void {
+        $this->expectException(\UnderflowException::class);
        if (!empty($bin)) {
            $this->_frame->addBuffer(static::encode($bin));
        }
@ -100,7 +90,7 @@ class FrameTest extends TestCase {
     * param int Given, what is the expected opcode
     * param string of 0|1 Each character represents a bit in the byte
     */
-    public static function firstByteProvider() {
+    public static function firstByteProvider(): array {
        return array(
            array(false, false, false, true,   8, '00011000'),
            array(true,  false, true,  false, 10, '10101010'),
@ -113,20 +103,16 @@ class FrameTest extends TestCase {

    /**
     * @dataProvider firstByteProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::isFinal
     */
-    public function testFinCodeFromBits($fin, $rsv1, $rsv2, $rsv3, $opcode, $bin) {
+    public function testFinCodeFromBits(bool $fin, bool $rsv1, bool $rsv2, bool $rsv3, int $opcode, string $bin): void {
        $this->_frame->addBuffer(static::encode($bin));
        $this->assertEquals($fin, $this->_frame->isFinal());
    }

    /**
     * @dataProvider firstByteProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::getRsv1
-     * covers Ratchet\RFC6455\Messaging\Frame::getRsv2
-     * covers Ratchet\RFC6455\Messaging\Frame::getRsv3
     */
-    public function testGetRsvFromBits($fin, $rsv1, $rsv2, $rsv3, $opcode, $bin) {
+    public function testGetRsvFromBits(bool $fin, bool $rsv1, bool $rsv2, bool $rsv3, int $opcode, string $bin): void {
        $this->_frame->addBuffer(static::encode($bin));
        $this->assertEquals($rsv1, $this->_frame->getRsv1());
        $this->assertEquals($rsv2, $this->_frame->getRsv2());
@ -135,32 +121,29 @@ class FrameTest extends TestCase {

    /**
     * @dataProvider firstByteProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::getOpcode
     */
-    public function testOpcodeFromBits($fin, $rsv1, $rsv2, $rsv3, $opcode, $bin) {
+    public function testOpcodeFromBits(bool $fin, bool $rsv1, bool $rsv2, bool $rsv3, int $opcode, string $bin): void {
        $this->_frame->addBuffer(static::encode($bin));
        $this->assertEquals($opcode, $this->_frame->getOpcode());
    }

    /**
     * @dataProvider UnframeMessageProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::isFinal
     */
-    public function testFinCodeFromFullMessage($msg, $encoded) {
+    public function testFinCodeFromFullMessage(string $msg, string $encoded): void {
        $this->_frame->addBuffer(base64_decode($encoded));
        $this->assertTrue($this->_frame->isFinal());
    }

    /**
     * @dataProvider UnframeMessageProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::getOpcode
     */
-    public function testOpcodeFromFullMessage($msg, $encoded) {
+    public function testOpcodeFromFullMessage(string $msg, string $encoded): void {
        $this->_frame->addBuffer(base64_decode($encoded));
        $this->assertEquals(1, $this->_frame->getOpcode());
    }

-    public static function payloadLengthDescriptionProvider() {
+    public static function payloadLengthDescriptionProvider(): array {
        return array(
            array(7,  '01110101'),
            array(7,  '01111101'),
@ -173,10 +156,8 @@ class FrameTest extends TestCase {

    /**
     * @dataProvider payloadLengthDescriptionProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::addBuffer
-     * covers Ratchet\RFC6455\Messaging\Frame::getFirstPayloadVal
     */
-    public function testFirstPayloadDesignationValue($bits, $bin) {
+    public function testFirstPayloadDesignationValue(int $bits, string $bin): void {
        $this->_frame->addBuffer(static::encode($this->_firstByteFinText));
        $this->_frame->addBuffer(static::encode($bin));
        $ref = new \ReflectionClass($this->_frame);
@ -185,22 +166,18 @@ class FrameTest extends TestCase {
        $this->assertEquals(bindec($bin), $cb->invoke($this->_frame));
    }

-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::getFirstPayloadVal
-     */
-    public function testFirstPayloadValUnderflow() {
+    public function testFirstPayloadValUnderflow(): void {
        $ref = new \ReflectionClass($this->_frame);
        $cb  = $ref->getMethod('getFirstPayloadVal');
        $cb->setAccessible(true);
-        $this->setExpectedException('UnderflowException');
+        $this->expectException(\UnderflowException::class);
        $cb->invoke($this->_frame);
    }

    /**
     * @dataProvider payloadLengthDescriptionProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::getNumPayloadBits
     */
-    public function testDetermineHowManyBitsAreUsedToDescribePayload($expected_bits, $bin) {
+    public function testDetermineHowManyBitsAreUsedToDescribePayload(int $expected_bits, string $bin): void {
        $this->_frame->addBuffer(static::encode($this->_firstByteFinText));
        $this->_frame->addBuffer(static::encode($bin));
        $ref = new \ReflectionClass($this->_frame);
@ -209,18 +186,15 @@ class FrameTest extends TestCase {
        $this->assertEquals($expected_bits, $cb->invoke($this->_frame));
    }

-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::getNumPayloadBits
-     */
-    public function testgetNumPayloadBitsUnderflow() {
+    public function testgetNumPayloadBitsUnderflow(): void {
        $ref = new \ReflectionClass($this->_frame);
        $cb  = $ref->getMethod('getNumPayloadBits');
        $cb->setAccessible(true);
-        $this->setExpectedException('UnderflowException');
+        $this->expectException(\UnderflowException::class);
        $cb->invoke($this->_frame);
    }

-    public function secondByteProvider() {
+    public function secondByteProvider(): array {
        return array(
            array(true,   1, '10000001'),
            array(false,  1, '00000001'),
@ -229,9 +203,8 @@ class FrameTest extends TestCase {
    }
    /**
     * @dataProvider secondByteProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::isMasked
     */
-    public function testIsMaskedReturnsExpectedValue($masked, $payload_length, $bin) {
+    public function testIsMaskedReturnsExpectedValue(bool $masked, int $payload_length, string $bin): void {
        $this->_frame->addBuffer(static::encode($this->_firstByteFinText));
        $this->_frame->addBuffer(static::encode($bin));
        $this->assertEquals($masked, $this->_frame->isMasked());
@ -239,18 +212,16 @@ class FrameTest extends TestCase {

    /**
     * @dataProvider UnframeMessageProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::isMasked
     */
-    public function testIsMaskedFromFullMessage($msg, $encoded) {
+    public function testIsMaskedFromFullMessage(string $msg, string $encoded): void {
        $this->_frame->addBuffer(base64_decode($encoded));
        $this->assertTrue($this->_frame->isMasked());
    }

    /**
     * @dataProvider secondByteProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::getPayloadLength
     */
-    public function testGetPayloadLengthWhenOnlyFirstFrameIsUsed($masked, $payload_length, $bin) {
+    public function testGetPayloadLengthWhenOnlyFirstFrameIsUsed(bool $masked, int $payload_length, string $bin): void {
        $this->_frame->addBuffer(static::encode($this->_firstByteFinText));
        $this->_frame->addBuffer(static::encode($bin));
        $this->assertEquals($payload_length, $this->_frame->getPayloadLength());
@ -258,15 +229,14 @@ class FrameTest extends TestCase {

    /**
     * @dataProvider UnframeMessageProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::getPayloadLength
     * @todo Not yet testing when second additional payload length descriptor
     */
-    public function testGetPayloadLengthFromFullMessage($msg, $encoded) {
+    public function testGetPayloadLengthFromFullMessage(string $msg, string $encoded): void {
        $this->_frame->addBuffer(base64_decode($encoded));
        $this->assertEquals(strlen($msg), $this->_frame->getPayloadLength());
    }

-    public function maskingKeyProvider() {
+    public function maskingKeyProvider(): array {
        $frame = new Frame;
        return array(
            array($frame->generateMaskingKey()),
@ -277,35 +247,30 @@ class FrameTest extends TestCase {

    /**
     * @dataProvider maskingKeyProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::getMaskingKey
     * @todo I I wrote the dataProvider incorrectly, skipping for now
     */
-    public function testGetMaskingKey($mask) {
+    public function testGetMaskingKey(string $mask): void {
        $this->_frame->addBuffer(static::encode($this->_firstByteFinText));
        $this->_frame->addBuffer(static::encode($this->_secondByteMaskedSPL));
        $this->_frame->addBuffer($mask);
        $this->assertEquals($mask, $this->_frame->getMaskingKey());
    }

-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::getMaskingKey
-     */
-    public function testGetMaskingKeyOnUnmaskedPayload() {
+    public function testGetMaskingKeyOnUnmaskedPayload(): void {
        $frame = new Frame('Hello World!');
        $this->assertEquals('', $frame->getMaskingKey());
    }

    /**
     * @dataProvider UnframeMessageProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::getPayload
     * @todo Move this test to bottom as it requires all methods of the class
     */
-    public function testUnframeFullMessage($unframed, $base_framed) {
+    public function testUnframeFullMessage(string $unframed, string $base_framed): void {
        $this->_frame->addBuffer(base64_decode($base_framed));
        $this->assertEquals($unframed, $this->_frame->getPayload());
    }

-    public static function messageFragmentProvider() {
+    public static function messageFragmentProvider(): array {
        return array(
            array(false, '', '', '', '', '')
        );
@ -313,9 +278,8 @@ class FrameTest extends TestCase {

    /**
     * @dataProvider UnframeMessageProvider
-     * covers Ratchet\RFC6455\Messaging\Frame::getPayload
     */
-    public function testCheckPiecingTogetherMessage($msg, $encoded) {
+    public function testCheckPiecingTogetherMessage(string $msg, string $encoded): void {
        $framed = base64_decode($encoded);
        for ($i = 0, $len = strlen($framed);$i < $len; $i++) {
            $this->_frame->addBuffer(substr($framed, $i, 1));
@ -323,12 +287,7 @@ class FrameTest extends TestCase {
        $this->assertEquals($msg, $this->_frame->getPayload());
    }

-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::__construct
-     * covers Ratchet\RFC6455\Messaging\Frame::getPayloadLength
-     * covers Ratchet\RFC6455\Messaging\Frame::getPayload
-     */
-    public function testLongCreate() {
+    public function testLongCreate(): void {
        $len = 65525;
        $pl  = $this->generateRandomString($len);
        $frame = new Frame($pl, true, Frame::OP_PING);
@ -339,20 +298,13 @@ class FrameTest extends TestCase {
        $this->assertEquals($pl, $frame->getPayload());
    }

-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::__construct
-     * covers Ratchet\RFC6455\Messaging\Frame::getPayloadLength
-     */
-    public function testReallyLongCreate() {
+    public function testReallyLongCreate(): void {
        $len = 65575;
        $frame = new Frame($this->generateRandomString($len));
        $this->assertEquals($len, $frame->getPayloadLength());
    }
-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::__construct
-     * covers Ratchet\RFC6455\Messaging\Frame::extractOverflow
-     */
-    public function testExtractOverflow() {
+
+    public function testExtractOverflow(): void {
        $string1 = $this->generateRandomString();
        $frame1  = new Frame($string1);
        $string2 = $this->generateRandomString();
@ -367,10 +319,7 @@ class FrameTest extends TestCase {
        $this->assertEquals($string2, $uncat->getPayload());
    }

-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::extractOverflow
-     */
-    public function testEmptyExtractOverflow() {
+    public function testEmptyExtractOverflow(): void {
        $string = $this->generateRandomString();
        $frame  = new Frame($string);
        $this->assertEquals($string, $frame->getPayload());
@ -378,10 +327,7 @@ class FrameTest extends TestCase {
        $this->assertEquals($string, $frame->getPayload());
    }

-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::getContents
-     */
-    public function testGetContents() {
+    public function testGetContents(): void {
        $msg = 'The quick brown fox jumps over the lazy dog.';
        $frame1 = new Frame($msg);
        $frame2 = new Frame($msg);
@ -390,10 +336,7 @@ class FrameTest extends TestCase {
        $this->assertEquals(strlen($frame1->getContents()) + 4, strlen($frame2->getContents()));
    }

-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::maskPayload
-     */
-    public function testMasking() {
+    public function testMasking(): void {
        $msg   = 'The quick brown fox jumps over the lazy dog.';
        $frame = new Frame($msg);
        $frame->maskPayload();
@ -401,10 +344,7 @@ class FrameTest extends TestCase {
        $this->assertEquals($msg, $frame->getPayload());
    }

-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::unMaskPayload
-     */
-    public function testUnMaskPayload() {
+    public function testUnMaskPayload(): void {
        $string = $this->generateRandomString();
        $frame  = new Frame($string);
        $frame->maskPayload()->unMaskPayload();
@ -412,10 +352,7 @@ class FrameTest extends TestCase {
        $this->assertEquals($string, $frame->getPayload());
    }

-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::generateMaskingKey
-     */
-    public function testGenerateMaskingKey() {
+    public function testGenerateMaskingKey(): void {
        $dupe = false;
        $done = array();
        for ($i = 0; $i < 10; $i++) {
@ -429,27 +366,20 @@ class FrameTest extends TestCase {
        $this->assertFalse($dupe);
    }

-    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::maskPayload
-     */
-    public function testGivenMaskIsValid() {
-        $this->setExpectedException('InvalidArgumentException');
+    public function testGivenMaskIsValid(): void {
+        $this->expectException(\InvalidArgumentException::class);
        $this->_frame->maskPayload('hello world');
    }

    /**
-     * covers Ratchet\RFC6455\Messaging\Frame::maskPayload
+     * @requires extension mbstring
     */
-    public function testGivenMaskIsValidAscii() {
-        if (!extension_loaded('mbstring')) {
-            $this->markTestSkipped("mbstring required for this test");
-            return;
-        }
-        $this->setExpectedException('OutOfBoundsException');
+    public function testGivenMaskIsValidAscii(): void {
+        $this->expectException(\OutOfBoundsException::class);
        $this->_frame->maskPayload('x✖');
    }

-    protected function generateRandomString($length = 10, $addSpaces = true, $addNumbers = true) {
+    protected function generateRandomString(int $length = 10, bool $addSpaces = true, bool $addNumbers = true): string {
        $characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!"$%&/()=[]{}'; // ยง
        $useChars = array();
        for($i = 0; $i < $length; $i++) {
@ -473,11 +403,8 @@ class FrameTest extends TestCase {
     * to set the payload length to 126 and then not recalculate it once the full length information was available.
     *
     * This is fixed by setting the defPayLen back to -1 before the underflow exception is thrown.
-     *
-     * covers Ratchet\RFC6455\Messaging\Frame::getPayloadLength
-     * covers Ratchet\RFC6455\Messaging\Frame::extractOverflow
     */
-    public function testFrameDeliveredOneByteAtATime() {
+    public function testFrameDeliveredOneByteAtATime(): void {
        $startHeader = "\x01\x7e\x01\x00"; // header for a text frame of 256 - non-final
        $framePayload = str_repeat("*", 256);
        $rawOverflow = "xyz";
--- a/tests/unit/Messaging/MessageBufferTest.php
+++ b/tests/unit/Messaging/MessageBufferTest.php
@ -9,13 +9,16 @@ use Ratchet\RFC6455\Messaging\MessageBuffer;
 use React\EventLoop\Factory;
 use PHPUnit\Framework\TestCase;

+/**
+ * @covers Ratchet\RFC6455\Messaging\MessageBuffer
+ */
 class MessageBufferTest extends TestCase
 {
    /**
     * This is to test that MessageBuffer can handle a large receive
     * buffer with many many frames without blowing the stack (pre-v0.4 issue)
     */
-    public function testProcessingLotsOfFramesInASingleChunk() {
+    public function testProcessingLotsOfFramesInASingleChunk(): void {
        $frame = new Frame('a', true, Frame::OP_TEXT);

        $frameRaw = $frame->getContents();
@ -26,7 +29,7 @@ class MessageBufferTest extends TestCase

        $messageBuffer = new MessageBuffer(
            new CloseFrameChecker(),
-            function (Message $message) use (&$messageCount) {
+            function (Message $message) use (&$messageCount): void {
                $messageCount++;
                $this->assertEquals('a', $message->getPayload());
            },
@ -39,7 +42,7 @@ class MessageBufferTest extends TestCase
        $this->assertEquals(1000, $messageCount);
    }

-    public function testProcessingMessagesAsynchronouslyWhileBlockingInMessageHandler() {
+    public function testProcessingMessagesAsynchronouslyWhileBlockingInMessageHandler(): void {
        $loop = Factory::create();

        $frameA = new Frame('a', true, Frame::OP_TEXT);
@ -49,7 +52,7 @@ class MessageBufferTest extends TestCase

        $messageBuffer = new MessageBuffer(
            new CloseFrameChecker(),
-            function (Message $message) use (&$messageCount, &$bReceived, $loop) {
+            static function (Message $message) use (&$messageCount, &$bReceived, $loop): void {
                $payload = $message->getPayload();
                $bReceived = $payload === 'b';

@ -61,7 +64,7 @@ class MessageBufferTest extends TestCase
            false
        );

-        $loop->addPeriodicTimer(0.1, function () use ($messageBuffer, $frameB, $loop) {
+        $loop->addPeriodicTimer(0.1, static function () use ($messageBuffer, $frameB, $loop): void {
            $loop->stop();
            $messageBuffer->onData($frameB->getContents());
        });
@ -71,7 +74,7 @@ class MessageBufferTest extends TestCase
        $this->assertTrue($bReceived);
    }

-    public function testInvalidFrameLength() {
+    public function testInvalidFrameLength(): void {
        $frame = new Frame(str_repeat('a', 200), true, Frame::OP_TEXT);

        $frameRaw = $frame->getContents();
@ -93,7 +96,7 @@ class MessageBufferTest extends TestCase

        $messageBuffer = new MessageBuffer(
            new CloseFrameChecker(),
-            function (Message $message) use (&$messageCount) {
+            static function (Message $message) use (&$messageCount): void {
                $messageCount++;
            },
            function (Frame $frame) use (&$controlFrame) {
@ -109,13 +112,13 @@ class MessageBufferTest extends TestCase
        $messageBuffer->onData($frameRaw);

        $this->assertEquals(0, $messageCount);
-        $this->assertTrue($controlFrame instanceof Frame);
+        $this->assertInstanceOf(Frame::class, $controlFrame);
        $this->assertEquals(Frame::OP_CLOSE, $controlFrame->getOpcode());
        $this->assertEquals([Frame::CLOSE_PROTOCOL], array_merge(unpack('n*', substr($controlFrame->getPayload(), 0, 2))));

    }

-    public function testFrameLengthTooBig() {
+    public function testFrameLengthTooBig(): void {
        $frame = new Frame(str_repeat('a', 200), true, Frame::OP_TEXT);

        $frameRaw = $frame->getContents();
@ -137,10 +140,10 @@ class MessageBufferTest extends TestCase

        $messageBuffer = new MessageBuffer(
            new CloseFrameChecker(),
-            function (Message $message) use (&$messageCount) {
+            static function (Message $message) use (&$messageCount): void {
                $messageCount++;
            },
-            function (Frame $frame) use (&$controlFrame) {
+            function (Frame $frame) use (&$controlFrame): void {
                $this->assertNull($controlFrame);
                $controlFrame = $frame;
            },
@ -153,12 +156,12 @@ class MessageBufferTest extends TestCase
        $messageBuffer->onData($frameRaw);

        $this->assertEquals(0, $messageCount);
-        $this->assertTrue($controlFrame instanceof Frame);
+        $this->assertInstanceOf(Frame::class, $controlFrame);
        $this->assertEquals(Frame::OP_CLOSE, $controlFrame->getOpcode());
        $this->assertEquals([Frame::CLOSE_TOO_BIG], array_merge(unpack('n*', substr($controlFrame->getPayload(), 0, 2))));
    }

-    public function testFrameLengthBiggerThanMaxMessagePayload() {
+    public function testFrameLengthBiggerThanMaxMessagePayload(): void {
        $frame = new Frame(str_repeat('a', 200), true, Frame::OP_TEXT);

        $frameRaw = $frame->getContents();
@ -169,10 +172,10 @@ class MessageBufferTest extends TestCase

        $messageBuffer = new MessageBuffer(
            new CloseFrameChecker(),
-            function (Message $message) use (&$messageCount) {
+            static function (Message $message) use (&$messageCount): void {
                $messageCount++;
            },
-            function (Frame $frame) use (&$controlFrame) {
+            function (Frame $frame) use (&$controlFrame): void {
                $this->assertNull($controlFrame);
                $controlFrame = $frame;
            },
@ -185,12 +188,12 @@ class MessageBufferTest extends TestCase
        $messageBuffer->onData($frameRaw);

        $this->assertEquals(0, $messageCount);
-        $this->assertTrue($controlFrame instanceof Frame);
+        $this->assertInstanceOf(Frame::class, $controlFrame);
        $this->assertEquals(Frame::OP_CLOSE, $controlFrame->getOpcode());
        $this->assertEquals([Frame::CLOSE_TOO_BIG], array_merge(unpack('n*', substr($controlFrame->getPayload(), 0, 2))));
    }

-    public function testSecondFrameLengthPushesPastMaxMessagePayload() {
+    public function testSecondFrameLengthPushesPastMaxMessagePayload(): void {
        $frame = new Frame(str_repeat('a', 200), false, Frame::OP_TEXT);
        $firstFrameRaw = $frame->getContents();
        $frame = new Frame(str_repeat('b', 200), true, Frame::OP_TEXT);
@ -202,10 +205,10 @@ class MessageBufferTest extends TestCase

        $messageBuffer = new MessageBuffer(
            new CloseFrameChecker(),
-            function (Message $message) use (&$messageCount) {
+            static function (Message $message) use (&$messageCount): void {
                $messageCount++;
            },
-            function (Frame $frame) use (&$controlFrame) {
+            function (Frame $frame) use (&$controlFrame): void {
                $this->assertNull($controlFrame);
                $controlFrame = $frame;
            },
@ -220,7 +223,7 @@ class MessageBufferTest extends TestCase
        $messageBuffer->onData(substr($secondFrameRaw, 0, 150));

        $this->assertEquals(0, $messageCount);
-        $this->assertTrue($controlFrame instanceof Frame);
+        $this->assertInstanceOf(Frame::class, $controlFrame);
        $this->assertEquals(Frame::OP_CLOSE, $controlFrame->getOpcode());
        $this->assertEquals([Frame::CLOSE_TOO_BIG], array_merge(unpack('n*', substr($controlFrame->getPayload(), 0, 2))));
    }
@ -258,15 +261,15 @@ class MessageBufferTest extends TestCase
     * @param string $phpConfigurationValue
     * @param int $expectedLimit
     */
-    public function testMemoryLimits($phpConfigurationValue, $expectedLimit) {
-        $method = new \ReflectionMethod('Ratchet\RFC6455\Messaging\MessageBuffer', 'getMemoryLimit');
+    public function testMemoryLimits(string $phpConfigurationValue, int $expectedLimit): void {
+        $method = new \ReflectionMethod(MessageBuffer::class, 'getMemoryLimit');
        $method->setAccessible(true);
        $actualLimit = $method->invoke(null, $phpConfigurationValue);

        $this->assertSame($expectedLimit, $actualLimit);
    }

-    public function phpConfigurationProvider() {
+    public function phpConfigurationProvider(): array {
        return [
            'without unit type, just bytes' => ['500', 500],
            '1 GB with big "G"' => ['1G', 1 * 1024 * 1024 * 1024],
@ -281,32 +284,30 @@ class MessageBufferTest extends TestCase
        ];
    }

-    /**
-     * @expectedException \InvalidArgumentException
-     */
-    public function testInvalidMaxFramePayloadSizes() {
-        $messageBuffer = new MessageBuffer(
+    public function testInvalidMaxFramePayloadSizes(): void {
+        $this->expectException(\InvalidArgumentException::class);
+
+        new MessageBuffer(
            new CloseFrameChecker(),
-            function (Message $message) {},
-            function (Frame $frame) {},
+            static function (Message $message): void {},
+            static function (Frame $frame): void {},
            false,
            null,
            0,
-            0x8000000000000000
+            -1
        );
    }

-    /**
-     * @expectedException \InvalidArgumentException
-     */
-    public function testInvalidMaxMessagePayloadSizes() {
-        $messageBuffer = new MessageBuffer(
+    public function testInvalidMaxMessagePayloadSizes(): void {
+        $this->expectException(\InvalidArgumentException::class);
+
+        new MessageBuffer(
            new CloseFrameChecker(),
-            function (Message $message) {},
-            function (Frame $frame) {},
+            static function (Message $message): void {},
+            static function (Frame $frame): void {},
            false,
            null,
-            0x8000000000000000,
+            -1,
            0
        );
    }
@ -318,9 +319,8 @@ class MessageBufferTest extends TestCase
     * @param int $expectedLimit
     *
     * @runInSeparateProcess
-     * @requires PHP 7.0
     */
-    public function testIniSizes($phpConfigurationValue, $expectedLimit) {
+    public function testIniSizes(string $phpConfigurationValue, int $expectedLimit): void {
        $value = @ini_set('memory_limit', $phpConfigurationValue);
        if ($value === false) {
           $this->markTestSkipped("Does not support setting the memory_limit lower than current memory_usage");
@ -328,8 +328,8 @@ class MessageBufferTest extends TestCase

        $messageBuffer = new MessageBuffer(
            new CloseFrameChecker(),
-            function (Message $message) {},
-            function (Frame $frame) {},
+            static function (Message $message): void {},
+            static function (Frame $frame): void {},
            false,
            null
        );
@ -349,9 +349,8 @@ class MessageBufferTest extends TestCase

    /**
     * @runInSeparateProcess
-     * @requires PHP 7.0
     */
-    public function testInvalidIniSize() {
+    public function testInvalidIniSize(): void {
        $value = @ini_set('memory_limit', 'lots of memory');
        if ($value === false) {
            $this->markTestSkipped("Does not support setting the memory_limit lower than current memory_usage");
--- a/tests/unit/Messaging/MessageTest.php
+++ b/tests/unit/Messaging/MessageTest.php
@ -13,20 +13,20 @@ class MessageTest extends TestCase {
    /** @var Message */
    protected $message;

-    public function setUp() {
+    protected function setUp(): void {
        $this->message = new Message;
    }

-    public function testNoFrames() {
+    public function testNoFrames(): void {
        $this->assertFalse($this->message->isCoalesced());
    }

-    public function testNoFramesOpCode() {
-        $this->setExpectedException('UnderflowException');
+    public function testNoFramesOpCode(): void {
+        $this->expectException(\UnderflowException::class);
        $this->message->getOpCode();
    }

-    public function testFragmentationPayload() {
+    public function testFragmentationPayload(): void {
        $a = 'Hello ';
        $b = 'World!';
        $f1 = new Frame($a, false);
@ -36,13 +36,13 @@ class MessageTest extends TestCase {
        $this->assertEquals($a . $b, $this->message->getPayload());
    }

-    public function testUnbufferedFragment() {
+    public function testUnbufferedFragment(): void {
        $this->message->addFrame(new Frame('The quick brow', false));
-        $this->setExpectedException('UnderflowException');
+        $this->expectException(\UnderflowException::class);
        $this->message->getPayload();
    }

-    public function testGetOpCode() {
+    public function testGetOpCode(): void {
        $this->message
            ->addFrame(new Frame('The quick brow', false, Frame::OP_TEXT))
            ->addFrame(new Frame('n fox jumps ov', false, Frame::OP_CONTINUE))
@ -51,7 +51,7 @@ class MessageTest extends TestCase {
        $this->assertEquals(Frame::OP_TEXT, $this->message->getOpCode());
    }

-    public function testGetUnBufferedPayloadLength() {
+    public function testGetUnBufferedPayloadLength(): void {
        $this->message
            ->addFrame(new Frame('The quick brow', false, Frame::OP_TEXT))
            ->addFrame(new Frame('n fox jumps ov', false, Frame::OP_CONTINUE))