Add test for ZipDownloader

tests/Composer/Test/Downloader/ZipDownloaderTest.php

@@ -0,0 +1,45 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Test\Downloader;
+
+use Composer\Util\Filesystem;
+use Composer\Downloader\ZipDownloader;
+
+class ZipDownloaderTest extends \PHPUnit_Framework_TestCase
+{
+    public function setUp()
+    {
+        if (!class_exists('ZipArchive')) {
+            $this->markTestSkipped('zip extension missing');
+        }
+    }
+
+    public function testErrorMessages()
+    {
+        $packageMock = $this->getMock('Composer\Package\PackageInterface');
+        $packageMock->expects($this->any())
+            ->method('getDistUrl')
+            ->will($this->returnValue('file://'.__FILE__))
+        ;
+
+        $io = $this->getMock('Composer\IO\IOInterface');
+        $downloader = new ZipDownloader($io);
+
+        try {
+            $downloader->download($packageMock, sys_get_temp_dir().'/composer-zip-test');
+            $this->fail('Download of invalid zip files should throw an exception');
+        } catch (\UnexpectedValueException $e) {
+            $this->assertContains('is not a zip archive', $e->getMessage());
+        }
+    }
+}