Update encode method to use type hinting for string|Response object

.github/workflows/test.yml

@@ -44,7 +44,7 @@ jobs:
           command: composer update --${{ matrix.stability }} --prefer-lowest --prefer-dist --no-interaction --no-progress --ansi
 
       - name: Static analysis
-        #continue-on-error: true
+        continue-on-error: true
         run: composer analyze
 
       - name: Execute tests

src/Connection/TcpConnection.php

@@ -457,6 +457,9 @@ public function send(mixed $sendBuffer, bool $raw = false): bool|null
             return false;
         }
 
+        // Fix null to empty string.
+        $sendBuffer ??= '';
+
         // Try to call protocol::encode($sendBuffer) before sending.
         if (false === $raw && $this->protocol !== null) {
             try {

src/Protocols/Http.php

@@ -19,6 +19,7 @@
 use Workerman\Connection\TcpConnection;
 use Workerman\Protocols\Http\Request;
 use Workerman\Protocols\Http\Response;
+use Stringable;
 use function clearstatcache;
 use function ctype_xdigit;
 use function filesize;
@@ -346,13 +347,13 @@
     /**
      * Http encode.
      *
-     * @param string|Response $response
+     * @param string|Stringable $response
      * @param TcpConnection $connection
      * @return string
      */
-    public static function encode(mixed $response, TcpConnection $connection): string
+    public static function encode(string|Stringable $response, TcpConnection $connection): string
     {
-        if (!is_object($response)) {
+        if (is_string($response)) {
             $extHeader = '';
             $contentType = 'text/html;charset=utf-8';
             foreach ($connection->headers as $name => $value) {
@@ -375,7 +376,7 @@
         }
 
         if ($connection->headers) {
             $response->withHeaders($connection->headers);
             $connection->headers = [];
         }
 
@@ -386,15 +387,15 @@
             clearstatcache();
             $fileSize = (int)filesize($file);
             $bodyLen = $length > 0 ? $length : $fileSize - $offset;
             $response->withHeaders([
                 'Content-Length' => $bodyLen,
                 'Accept-Ranges' => 'bytes',
             ]);
 
             if ($offset || $length) {
                 $offsetEnd = $offset + $bodyLen - 1;
                 $response->header('Content-Range', "bytes $offset-$offsetEnd/$fileSize");
                 $response->withStatus(206);
             }
             if ($bodyLen < 2 * 1024 * 1024) {
                 $connection->send($response . file_get_contents($file, false, null, $offset, $bodyLen), true);