test: verify SocketPost correctly rejects unsupported HTTP protocols

Author: SNO7E-G

tests/ReCaptcha/RequestMethod/SocketPostTest.php

@@ -269,4 +269,19 @@ public function testBadResponseReturnsErrorWhenHttp11(): void
 
         $this->assertEquals('{"success": false, "error-codes": ["'.ReCaptcha::E_BAD_RESPONSE.'"]}', $response);
     }
+
+    public function testBadResponseReturnsErrorWhenHttp2(): void
+    {
+        SocketPostGlobalState::$fgetsResponses = [
+            "HTTP/2.0 200 OK\r\n",
+            "Content-Type: application/json\r\n",
+            "\r\n",
+            'RESPONSEBODY',
+        ];
+
+        $sp = new SocketPost();
+        $response = $sp->submit(new RequestParameters('secret', 'response'));
+
+        $this->assertEquals('{"success": false, "error-codes": ["'.ReCaptcha::E_BAD_RESPONSE.'"]}', $response);
+    }
 }