make compatible with stream interface

composer.json

@@ -9,7 +9,7 @@
         }
     ],
     "require": {
-        "php": "^7.2 || ^8.0",
+        "php": "^7.4 || ^8.0",
         "nyholm/psr7": "^1.3",
         "php-http/httplug": "^2.0",
         "psr/http-client": "^1.0",

phpunit.xml.dist

@@ -8,7 +8,6 @@
   <testsuites>
     <testsuite name="Socket Client Test Suite">
       <directory>tests/</directory>
-      <exclude>tests/SocketClientFeatureTest.php</exclude>
     </testsuite>
   </testsuites>
   <php>

src/Stream.php

@@ -61,7 +61,7 @@ public function __construct(RequestInterface $request, $socket, ?int $size = nul
         $this->request = $request;
     }
 
-    public function __toString()
+    public function __toString(): string
     {
         try {
             return $this->getContents();
@@ -70,7 +70,7 @@ public function __toString()
         }
     }
 
-    public function close()
+    public function close(): void
     {
         if ($this->isDetached || null === $this->socket) {
             throw new StreamException('Stream is detached');
@@ -93,12 +93,12 @@ public function detach()
     /**
      * @return int<0, max>|null
      */
-    public function getSize()
+    public function getSize(): ?int
     {
         return $this->size;
     }
 
-    public function tell()
+    public function tell(): int
     {
         if ($this->isDetached || null === $this->socket) {
             throw new StreamException('Stream is detached');
@@ -111,7 +111,7 @@ public function tell()
         return $tell;
     }
 
-    public function eof()
+    public function eof(): bool
     {
         if ($this->isDetached || null === $this->socket) {
             throw new StreamException('Stream is detached');
@@ -120,46 +120,40 @@ public function eof()
         return feof($this->socket);
     }
 
-    public function isSeekable()
+    public function isSeekable(): bool
     {
         return false;
     }
 
-    /**
-     * @return void
-     */
-    public function seek($offset, $whence = SEEK_SET)
+    public function seek($offset, $whence = SEEK_SET): void
     {
         throw new StreamException('This stream is not seekable');
     }
 
-    /**
-     * @return void
-     */
-    public function rewind()
+    public function rewind(): void
     {
         throw new StreamException('This stream is not seekable');
     }
 
-    public function isWritable()
+    public function isWritable(): bool
     {
         return false;
     }
 
-    public function write($string)
+    public function write($string): int
     {
         throw new StreamException('This stream is not writable');
     }
 
-    public function isReadable()
+    public function isReadable(): bool
     {
         return true;
     }
 
     /**
      * @param int<0, max> $length
      */
-    public function read($length)
+    public function read($length): string
     {
         if ($this->isDetached || null === $this->socket) {
             throw new StreamException('Stream is detached');
@@ -197,7 +191,7 @@ public function read($length)
         return $read;
     }
 
-    public function getContents()
+    public function getContents(): string
     {
         if ($this->isDetached || null === $this->socket) {
             throw new StreamException('Stream is detached');