Added additional test cases.

src/Client.php

@@ -87,18 +87,14 @@ public function authenticate($username, $password = null)
     /**
      * {@inheritdoc}
      */
-    public function connectAndAuthenticate($username = null, $password = null)
+    public function connectAndAuthenticate($username, $password = null)
     {
         $response = $this->connect();
 
-        if (!in_array($response->getStatusCode(), [Response::$codes['PostingAllowed'], Response::$code['PostingProhibited']])) {
+        if (!in_array($response->getStatusCode(), [Response::$codes['PostingAllowed'], Response::$codes['PostingProhibited']])) {
             throw new RuntimeException(sprintf('Unsuccessful response received: %s', (string) $response));
         }
 
-        if ($username === null) {
-            return $response;
-        }
-
         return $this->authenticate($username, $password);
     }
 
@@ -155,8 +151,7 @@ public function overviewFormat()
      */
     public function post($groups, $subject, $body, $from, $headers = null)
     {
-        $command = $this->sendCommand(new Command\PostCommand());
-        $response = $command->getResponse();
+        $response = $this->sendCommand(new Command\PostCommand());
 
         if ($response->getStatusCode() === Response::$codes['SendArticle']) {
             $response = $this->postArticle($groups, $subject, $body, $from, $headers);

src/ClientInterface.php

@@ -42,15 +42,15 @@ public function disconnect();
     public function authenticate($username, $password = null);
 
     /**
-     * Connect and optionally authenticate with the NNTP server if
-     * a username and/or password are given.
+     * Connect and optionally authenticate with the server if
+     * a username and optional password are given.
      *
-     * @param string|null $username
+     * @param string      $username
      * @param string|null $password
      *
      * @return ResponseInterface
      */
-    public function connectAndAuthenticate($username = null, $password = null);
+    public function connectAndAuthenticate($username, $password = null);
 
     /**
      * Send the AUTHINFO command.

src/Command/BodyCommand.php

@@ -30,7 +30,7 @@ class BodyCommand extends Command implements CommandInterface
     /**
      * Constructor.
      *
-     * @param string $article the number or msg-id of the article
+     * @param string $article
      */
     public function __construct($article)
     {

src/Connection/Connection.php

@@ -94,7 +94,7 @@ public function sendCommand(CommandInterface $command)
         $commandString = $command();
 
         // NNTP/RFC977 only allows command up to 512 (-2 \r\n) chars.
-        if (!strlen($commandString) > 510) {
+        if (strlen($commandString) > 510) {
             throw new InvalidArgumentException('Failed to write to socket: command exceeded 510 characters');
         }