Adding the HEAD command

src/Client.php

@@ -114,6 +114,14 @@ public function body($article)
         return $this->sendCommand(new Command\BodyCommand($article));
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function head($article)
+    {
+        return $this->sendCommand(new Command\HeadCommand($article));
+    }
+
     /**
      * {@inheritdoc}
      */

src/Command/HeadCommand.php

@@ -0,0 +1,72 @@
+<?php
+
+/*
+ * This file is part of the NNTP library.
+ *
+ * (c) Robin van der Vleuten <robin@webstronauts.co>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Rvdv\Nntp\Command;
+
+use Rvdv\Nntp\Exception\RuntimeException;
+use Rvdv\Nntp\Response\MultiLineResponse;
+use Rvdv\Nntp\Response\Response;
+
+/**
+ * HeadCommand.
+ *
+ * @author elabz
+ */
+class HeadCommand extends Command implements CommandInterface
+{
+    /**
+     * @var string
+     */
+    private $article;
+
+    /**
+     * Constructor.
+     *
+     * @param string $article
+     */
+    public function __construct($article)
+    {
+        $this->article = $article;
+
+        parent::__construct(true);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function __invoke()
+    {
+        return sprintf('HEAD %s', $this->article);
+    }
+
+    /**
+     * @return string
+     */
+    public function onHeadFollows(MultiLineResponse $response)
+    {
+        return implode("\r\n", $response->getLines());
+    }
+
+    public function onNoNewsGroupCurrentSelected(Response $response)
+    {
+        throw new RuntimeException('A group must be selected first before getting an article header.', $response->getStatusCode());
+    }
+
+    public function onNoSuchArticleNumber(Response $response)
+    {
+        throw new RuntimeException('No article with that number.', $response->getStatusCode());
+    }
+
+    public function onNoSuchArticleId(Response $response)
+    {
+        throw new RuntimeException('No article with that message-id.', $response->getStatusCode());
+    }
+}

src/Response/Response.php

@@ -34,6 +34,7 @@ class Response implements ResponseInterface
         'GroupSelected' => 211, // rfc 3977
         'InformationFollows' => 215, // rfc 2980
         'ArticleFollows' => 220, //rfc 3977
+        'HeadFollows' => 221, //rfc 3977 Section 6.2.2
         'BodyFollows' => 222, //rfc 3977
         'OverviewInformationFollows' => 224, // rfc 2980
         'ArticleReceived' => 240, //rfc 3977

tests/ClientTest.php

@@ -328,6 +328,7 @@ public function getClassesForCommandMethods()
         return [
             [Command\AuthInfoCommand::class, 'authInfo', ['USER', 'user']],
             [Command\BodyCommand::class, 'body', ['1234']],
+            [Command\HeadCommand::class, 'head', ['12345']],
             [Command\GroupCommand::class, 'group', ['php.doc']],
             [Command\HelpCommand::class, 'help', []],
             [Command\ListCommand::class, 'listGroups', ['php', []]],

tests/Command/HeadCommandTest.php

@@ -0,0 +1,113 @@
+<?php
+
+/*
+ * This file is part of the NNTP library.
+ *
+ * (c) Robin van der Vleuten <robin@webstronauts.co>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Rvdv\Nntp\Tests\Command;
+
+use Rvdv\Nntp\Command\HeadCommand;
+
+/**
+ * HeadCommandTest.
+ *
+ * @author Robin van der Vleuten <robin@webstronauts.co>
+ */
+class HeadCommandTest extends \PHPUnit_Framework_TestCase
+{
+    public function testItExpectsMultilineResponses()
+    {
+        $command = $this->createCommandInstance();
+        $this->assertTrue($command->isMultiLine());
+    }
+
+    public function testItNotExpectsCompressedResponses()
+    {
+        $command = $this->createCommandInstance();
+        $this->assertFalse($command->isCompressed());
+    }
+
+    public function testItReturnsStringWhenExecuting()
+    {
+        $command = $this->createCommandInstance();
+        $this->assertEquals('HEAD 12345', $command());
+    }
+
+    public function testItReceivesAResultWhenHeadFollowsResponse()
+    {
+        $command = $this->createCommandInstance();
+
+        $response = $this->getMockBuilder('Rvdv\Nntp\Response\MultiLineResponse')
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $lines = ['Message-ID: <1234567890@1234567890.com>', 'Date: Thu, 28 Sep 2017 12:56:35 +0000', 'Newsgroups: php.announce'];
+
+        $response->expects($this->once())
+            ->method('getLines')
+            ->will($this->returnValue($lines));
+
+        $this->assertEquals(implode("\r\n", $lines), $command->onHeadFollows($response));
+    }
+
+    public function testItErrorsWhenGroupNotSelectedResponse()
+    {
+        $command = $this->createCommandInstance();
+
+        $response = $this->getMockBuilder('Rvdv\Nntp\Response\Response')
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        try {
+            $command->onNoNewsGroupCurrentSelected($response);
+            $this->fail('->onNoNewsGroupCurrentSelected() throws a Rvdv\Nntp\Exception\RuntimeException because the server indicated a newsgroup has not been selected');
+        } catch (\Exception $e) {
+            $this->assertInstanceof('Rvdv\Nntp\Exception\RuntimeException', $e, '->onNoNewsGroupCurrentSelected() throws a Rvdv\Nntp\Exception\RuntimeException because the server indicated a newsgroup has not been selected');
+        }
+    }
+
+    public function testItErrorsWhenNoSuchArticleNumberResponse()
+    {
+        $command = $this->createCommandInstance();
+
+        $response = $this->getMockBuilder('Rvdv\Nntp\Response\Response')
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        try {
+            $command->onNoSuchArticleNumber($response);
+            $this->fail('->onNoSuchArticleNumber() throws a Rvdv\Nntp\Exception\RuntimeException because the server indicated the article number does not exist');
+        } catch (\Exception $e) {
+            $this->assertInstanceof('Rvdv\Nntp\Exception\RuntimeException', $e, '->onNoSuchArticleNumber() throws a Rvdv\Nntp\Exception\RuntimeException because the server indicated the article number does not exist');
+        }
+    }
+
+    public function testItErrorsWhenNoSuchArticleIdResponse()
+    {
+        $command = $this->createCommandInstance();
+
+        $response = $this->getMockBuilder('Rvdv\Nntp\Response\Response')
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        try {
+            $command->onNoSuchArticleId($response);
+            $this->fail('->onNoSuchArticleId() throws a Rvdv\Nntp\Exception\RuntimeException because the server indicated the article id does not exist');
+        } catch (\Exception $e) {
+            $this->assertInstanceof('Rvdv\Nntp\Exception\RuntimeException', $e, '->onNoSuchArticleId() throws a Rvdv\Nntp\Exception\RuntimeException because the server indicated the article id does not exist');
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function createCommandInstance()
+    {
+        return new HeadCommand('12345');
+    }
+}