Add Psalm and fix issues

.travis.yml

@@ -23,6 +23,7 @@ install:
 script:
   - php -dzend.assertions=1 -dassert.exception=1 vendor/bin/phpunit --coverage-text --verbose --coverage-clover build/logs/clover.xml
   - PHP_CS_FIXER_IGNORE_ENV=1 php vendor/bin/php-cs-fixer --diff --dry-run -v fix
+  - vendor/bin/psalm
 
 after_script:
   - wget https://github.com/php-coveralls/php-coveralls/releases/download/v2.2.0/php-coveralls.phar

composer.json

@@ -38,7 +38,8 @@
     "require-dev": {
         "phpunit/phpunit": "^8 || ^7",
         "amphp/phpunit-util": "^1.1.2",
-        "amphp/php-cs-fixer-config": "dev-master"
+        "amphp/php-cs-fixer-config": "dev-master",
+        "vimeo/psalm": "^3.11@dev"
     },
     "suggest": {
         "ext-zlib": "Required for compression"

psalm.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0"?>
+<psalm
+    errorLevel="2"
+    resolveFromConfigFile="true"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="https://getpsalm.org/schema/config"
+    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
+>
+    <projectFiles>
+        <directory name="src"/>
+        <ignoreFiles>
+            <directory name="vendor"/>
+        </ignoreFiles>
+    </projectFiles>
+</psalm>

src/Client.php

@@ -142,8 +142,8 @@ public function getInfo(): ClientMetadata;
      * @param int    $code
      * @param string $reason
      *
-     * @return Promise<[int, string]> Resolves with an array containing the close code used and the close reason.
-     *                                These may differ from those provided if the connection was closed prior.
+     * @return Promise<array> Resolves with an array containing the close code at key 0 and the close reason at key 1.
+     *                        These may differ from those provided if the connection was closed prior.
      */
     public function close(int $code = Code::NORMAL_CLOSE, string $reason = ''): Promise;
 

src/ClientMetadata.php

@@ -23,23 +23,49 @@ final class ClientMetadata
     /** @var string|null */
     public $closeReason;
 
-    // Timestamps of when the event occurred.
+    /** @var int */
     public $connectedAt = 0;
+
+    /** @var int */
     public $closedAt = 0;
+
+    /** @var int */
     public $lastReadAt = 0;
+
+    /** @var int */
     public $lastSentAt = 0;
+
+    /** @var int */
     public $lastDataReadAt = 0;
+
+    /** @var int */
     public $lastDataSentAt = 0;
+
+    /** @var int */
     public $lastHeartbeatAt = 0;
 
-    // Simple counters.
+    /** @var int */
     public $bytesRead = 0;
+
+    /** @var int */
     public $bytesSent = 0;
+
+    /** @var int */
     public $framesRead = 0;
+
+    /** @var int */
     public $framesSent = 0;
+
+    /** @var int */
     public $messagesRead = 0;
+
+    /** @var int */
     public $messagesSent = 0;
+
+    /** @var int */
     public $pingCount = 0;
+
+    /** @var int */
     public $pongCount = 0;
 
     /** @var bool */

src/Message.php

@@ -7,7 +7,7 @@
 use Amp\Promise;
 
 /**
- * This class allows streamed and buffered access to the websocket message by extending Payload.
+ * This class allows streamed and buffered access to the websocket message.
  */
 final class Message implements InputStream
 {

src/Options.php

@@ -4,18 +4,43 @@
 
 final class Options
 {
+    /** @var int */
     private $streamThreshold = 32768; // 32KB
+
+    /** @var int */
     private $frameSplitThreshold = 32768; // 32KB
+
+    /** @var int */
     private $bytesPerSecondLimit = 1048576; // 1MB
+
+    /** @var int */
     private $framesPerSecondLimit = 100;
+
+    /** @var int */
     private $frameSizeLimit = 2097152; // 2MB
+
+    /** @var int */
     private $messageSizeLimit = 10485760; // 10MB
+
+    /** @var bool */
     private $textOnly = false;
+
+    /** @var bool */
     private $validateUtf8 = true;
+
+    /** @var int */
     private $closePeriod = 3;
+
+    /** @var bool */
     private $compressionEnabled = false;
+
+    /** @var bool */
     private $heartbeatEnabled = true;
+
+    /** @var int */
     private $heartbeatPeriod = 10;
+
+    /** @var int */
     private $queuedPingLimit = 3;
 
     /**

src/Rfc6455Client.php

@@ -36,7 +36,7 @@ final class Rfc6455Client implements Client
     /** @var string|null */
     private static $watcher;
 
-    /** @var LRUCache Least-recently-used cache of next ping (heartbeat) times. */
+    /** @var LRUCache&\IteratorAggregate Least-recently-used cache of next ping (heartbeat) times. */
     private static $heartbeatTimeouts;
 
     /** @var int Cached current time. */
@@ -115,6 +115,7 @@ public function getIterator(): \Iterator
                 self::$framesReadInLastSecond = [];
 
                 if (!empty(self::$rateDeferreds)) {
+                    /** @psalm-suppress PossiblyNullArgument */
                     Loop::unreference(self::$watcher);
 
                     $rateDeferreds = self::$rateDeferreds;
@@ -131,7 +132,6 @@ public function getIterator(): \Iterator
                     }
 
                     $client = self::$clients[$clientId];
-                    \assert($client instanceof self);
                     self::$heartbeatTimeouts->put($clientId, self::$now + $client->options->getHeartbeatPeriod());
 
                     if ($client->getUnansweredPingCount() > $client->options->getQueuedPingLimit()) {
@@ -210,7 +210,7 @@ public function getTlsInfo(): ?TlsInfo
 
     public function getCloseCode(): int
     {
-        if (!$this->metadata->closedAt) {
+        if ($this->metadata->closeCode === null) {
             throw new \Error('The client has not closed');
         }
 
@@ -219,7 +219,7 @@ public function getCloseCode(): int
 
     public function getCloseReason(): string
     {
-        if (!$this->metadata->closedAt) {
+        if ($this->metadata->closeReason === null) {
             throw new \Error('The client has not closed');
         }
 
@@ -274,6 +274,7 @@ private function read(): \Generator
 
                 if ((self::$framesReadInLastSecond[$this->metadata->id] ?? 0) >= $maxFramesPerSecond
                     || self::$bytesReadInLastSecond[$this->metadata->id] >= $maxBytesPerSecond) {
+                    /** @psalm-suppress PossiblyNullArgument */
                     Loop::reference(self::$watcher); // Reference watcher to keep loop running until rate limit released.
                     self::$rateDeferreds[$this->metadata->id] = $deferred = new Deferred;
                     yield $deferred->promise();
@@ -438,7 +439,7 @@ private function onError(int $code, string $reason): void
 
     public function send(string $data): Promise
     {
-        \assert(\preg_match('//u', $data), 'Text data must be UTF-8');
+        \assert((bool) \preg_match('//u', $data), 'Text data must be UTF-8');
         return $this->lastWrite = new Coroutine($this->sendData($data, Opcode::TEXT));
     }
 
@@ -495,6 +496,7 @@ private function sendData(string $data, int $opcode): \Generator
                     $data = (string) \substr($data, $length);
 
                     if ($compress) {
+                        /** @psalm-suppress PossiblyNullReference */
                         $chunk = $this->compressionContext->compress($chunk, false);
                     }
 
@@ -505,6 +507,7 @@ private function sendData(string $data, int $opcode): \Generator
             }
 
             if ($compress) {
+                /** @psalm-suppress PossiblyNullReference */
                 $data = $this->compressionContext->compress($data, true);
             }
 
@@ -551,6 +554,7 @@ private function sendStream(InputStream $stream, int $opcode): \Generator
                 }
 
                 if ($compress) {
+                    /** @psalm-suppress PossiblyNullReference */
                     $buffer = $this->compressionContext->compress($buffer, false);
                 }
 
@@ -562,6 +566,7 @@ private function sendStream(InputStream $stream, int $opcode): \Generator
             }
 
             if ($compress) {
+                /** @psalm-suppress PossiblyNullReference */
                 $buffer = $this->compressionContext->compress($buffer, true);
             }
 
@@ -595,7 +600,7 @@ private function write(string $data, int $opcode, int $rsv = 0, bool $isFinal =
     private function compile(string $data, int $opcode, int $rsv, bool $isFinal): string
     {
         $length = \strlen($data);
-        $w = \chr(($isFinal << 7) | ($rsv << 4) | $opcode);
+        $w = \chr(((int) $isFinal << 7) | ($rsv << 4) | $opcode);
 
         $maskFlag = $this->masked ? 0x80 : 0;
 
@@ -677,14 +682,17 @@ public function close(int $code = Code::NORMAL_CLOSE, string $reason = ''): Prom
             $onClose = $this->onClose;
             $this->onClose = null;
 
-            foreach ($onClose as $callback) {
-                Promise\rethrow(call($callback, $this, $code, $reason));
+            if ($onClose !== null) {
+                foreach ($onClose as $callback) {
+                    Promise\rethrow(call($callback, $this, $code, $reason));
+                }
             }
 
             unset(self::$clients[$this->metadata->id]);
             self::$heartbeatTimeouts->remove($this->metadata->id);
 
             if (empty(self::$clients)) {
+                /** @psalm-suppress PossiblyNullArgument */
                 Loop::cancel(self::$watcher);
                 self::$watcher = null;
                 self::$heartbeatTimeouts = null;
@@ -747,7 +755,7 @@ private function parser(): \Generator
             $rsv = ($firstByte & 0b01110000) >> 4;
             $opcode = $firstByte & 0b00001111;
             $isMasked = (bool) ($secondByte & 0b10000000);
-            $maskingKey = null;
+            $maskingKey = '';
             $frameLength = $secondByte & 0b01111111;
 
             if ($opcode >= 3 && $opcode <= 7) {
@@ -914,6 +922,7 @@ private function parser(): \Generator
             }
 
             if ($compressed) {
+                /** @psalm-suppress PossiblyNullReference */
                 $payload = $compressionContext->decompress($payload, $final);
 
                 if ($payload === null) { // Decompression failed.
@@ -939,6 +948,7 @@ private function parser(): \Generator
                     }
                 }
 
+                /** @psalm-suppress PossiblyUndefinedVariable Defined in either condition above. */
                 if (!$valid) {
                     $this->onError(
                         Code::INCONSISTENT_FRAME_DATA_TYPE,

src/Rfc7692Compression.php

@@ -134,9 +134,9 @@ private static function fromHeader(bool $isServer, string $headerIn, ?string &$h
     private $deflate;
     /** @var resource */
     private $inflate;
-    /** @var bool */
+    /** @var int */
     private $sendingFlushMode;
-    /** @var bool */
+    /** @var int */
     private $receivingFlushMode;
 
     private function __construct(