Added unit test in files app for sort function in helper class

Added unit test for the Helper class in the files app that tests the
different sort orders.

apps/files/lib/helper.php

@@ -1,7 +1,16 @@
 <?php
+/**
+ * Copyright (c) 2014 Vincent Petry <pvince81@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
 
 namespace OCA\Files;
 
+/**
+ * Helper class for manipulating file information
+ */
 class Helper
 {
 	public static function buildFileStorageStatistics($dir) {
@@ -57,7 +66,7 @@ class Helper
 	 * @param \OCP\Files\FileInfo $b file
 	 * @return int -1 if $a must come before $b, 1 otherwise
 	 */
-	public static function fileCmp($a, $b) {
+	public static function compareFileNames($a, $b) {
 		$aType = $a->getType();
 		$bType = $b->getType();
 		if ($aType === 'dir' and $bType !== 'dir') {
@@ -76,7 +85,7 @@ class Helper
 	 * @param \OCP\Files\FileInfo $b file
 	 * @return int -1 if $a must come before $b, 1 otherwise
 	 */
-	public static function mtimeCmp($a, $b) {
+	public static function compareTimestamp($a, $b) {
 		$aTime = $a->getMTime();
 		$bTime = $b->getMTime();
 		return $aTime - $bTime;
@@ -89,7 +98,7 @@ class Helper
 	 * @param \OCP\Files\FileInfo $b file
 	 * @return int -1 if $a must come before $b, 1 otherwise
 	 */
-	public static function sizeCmp($a, $b) {
+	public static function compareSize($a, $b) {
 		$aSize = $a->getSize();
 		$bSize = $b->getSize();
 		return $aSize - $bSize;
@@ -165,11 +174,11 @@ class Helper
 	 * @return \OCP\Files\FileInfo[] sorted files
 	 */
 	public static function sortFiles($files, $sortAttribute = 'name', $sortDescending = false) {
-		$sortFunc = 'fileCmp';
+		$sortFunc = 'compareFileNames';
 		if ($sortAttribute === 'mtime') {
-			$sortFunc = 'mtimeCmp';
+			$sortFunc = 'compareTimestamp';
 		} else if ($sortAttribute === 'size') {
-			$sortFunc = 'sizeCmp';
+			$sortFunc = 'compareSize';
 		}
 		usort($files, array('\OCA\Files\Helper', $sortFunc));
 		if ($sortDescending) {

apps/files/tests/helper.php

@@ -0,0 +1,98 @@
+<?php
+/**
+ * Copyright (c) 2014 Vincent Petry <pvince81@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+require_once __DIR__ . '/../lib/helper.php';
+
+use OCA\Files;
+
+/**
+ * Class Test_Files_Helper
+ */
+class Test_Files_Helper extends \PHPUnit_Framework_TestCase {
+
+	private function makeFileInfo($name, $size, $mtime, $isDir = false) {
+		return new \OC\Files\FileInfo(
+			'/',
+			null,
+			'/',
+			array(
+				'name' => $name,
+				'size' => $size,
+				'mtime' => $mtime,
+				'type' => $isDir ? 'dir' : 'file',
+				'mimetype' => $isDir ? 'httpd/unix-directory' : 'application/octet-stream'
+			)	
+		);
+	}
+
+	/**
+	 * Returns a file list for testing
+	 */
+	private function getTestFileList() {
+		return array(
+			self::makeFileInfo('a.txt', 4, 1000),
+			self::makeFileInfo('q.txt', 5, 150),
+			self::makeFileInfo('subdir2', 87, 128, true),
+			self::makeFileInfo('b.txt', 166, 800),
+			self::makeFileInfo('o.txt', 12, 100),
+			self::makeFileInfo('subdir', 88, 125, true),
+		);
+	}
+
+	function sortDataProvider() {
+		return array(
+			array(
+				'name',
+				false,
+				array('subdir', 'subdir2', 'a.txt', 'b.txt', 'o.txt', 'q.txt'),
+			),
+			array(
+				'name',
+				true,
+				array('q.txt', 'o.txt', 'b.txt', 'a.txt', 'subdir2', 'subdir'),
+			),
+			array(
+				'size',
+				false,
+				array('a.txt', 'q.txt', 'o.txt', 'subdir2', 'subdir', 'b.txt'),
+			),
+			array(
+				'size',
+				true,
+				array('b.txt', 'subdir', 'subdir2', 'o.txt', 'q.txt', 'a.txt'),
+			),
+			array(
+				'mtime',
+				false,
+				array('o.txt', 'subdir', 'subdir2', 'q.txt', 'b.txt', 'a.txt'),
+			),
+			array(
+				'mtime',
+				true,
+				array('a.txt', 'b.txt', 'q.txt', 'subdir2', 'subdir', 'o.txt'),
+			),
+		);
+	}
+
+	/**
+	 * @dataProvider sortDataProvider
+	 */
+	public function testSortByName($sort, $sortDescending, $expectedOrder) {
+		$files = self::getTestFileList();
+		$files = \OCA\Files\Helper::sortFiles($files, $sort, $sortDescending);
+		$fileNames = array();
+		foreach ($files as $fileInfo) {
+			$fileNames[] = $fileInfo->getName();
+		}
+		$this->assertEquals(
+			$expectedOrder,
+			$fileNames
+		);	
+	}
+
+}