Fix package sorting

PackageSorter weighs the importance of a package
by counting how many times it is required by other packages.
This works by calculating the weight for each package name.

However currently the package index of the package array
is currently passed the weigh function, which basically
disables package sorting.

The reason for that is, that a package repository previously
returned the package list as associative array with  package name as keys,
but currently just as an array with integer keys.

Therefore we must extract the package name from the package
before passing it to the weigh function.

src/Composer/Util/PackageSorter.php

@@ -55,9 +55,9 @@ class PackageSorter
 
         $weightList = array();
 
-        foreach ($packages as $name => $package) {
+        foreach ($packages as $index => $package) {
-            $weight = $computeImportance($name);
+            $weight = $computeImportance($package->getName());
-            $weightList[$name] = $weight;
+            $weightList[$index] = $weight;
         }
 
         $stable_sort = function (&$array) {
@@ -84,8 +84,8 @@ class PackageSorter
 
         $sortedPackages = array();
 
-        foreach (array_keys($weightList) as $name) {
+        foreach (array_keys($weightList) as $index) {
-            $sortedPackages[] = $packages[$name];
+            $sortedPackages[] = $packages[$index];
         }
         return $sortedPackages;
     }

tests/Composer/Test/Util/PackageSorterTest.php

@@ -0,0 +1,129 @@
+<?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\Util;
+
+use Composer\Package\Link;
+use Composer\Package\Package;
+use Composer\Test\TestCase;
+use Composer\Util\PackageSorter;
+
+class PackageSorterTest extends TestCase
+{
+    public function testSortingDoesNothingWithNoDependencies()
+    {
+        $packages[] = $this->createPackage('foo/bar1', array());
+        $packages[] = $this->createPackage('foo/bar2', array());
+        $packages[] = $this->createPackage('foo/bar3', array());
+        $packages[] = $this->createPackage('foo/bar4', array());
+
+        $sortedPackages = PackageSorter::sortPackages($packages);
+
+        self::assertSame($packages, $sortedPackages);
+    }
+
+    public function sortingOrdersDependenciesHigherThanPackageDataProvider()
+    {
+        return array(
+            'one package is dep' => array(
+                array(
+                    $this->createPackage('foo/bar1', array('foo/bar4')),
+                    $this->createPackage('foo/bar2', array('foo/bar4')),
+                    $this->createPackage('foo/bar3', array('foo/bar4')),
+                    $this->createPackage('foo/bar4', array()),
+                ),
+                array(
+                    'foo/bar4',
+                    'foo/bar1',
+                    'foo/bar2',
+                    'foo/bar3',
+                ),
+            ),
+            'one package has more deps' => array(
+                array(
+                    $this->createPackage('foo/bar1', array('foo/bar2')),
+                    $this->createPackage('foo/bar2', array('foo/bar4')),
+                    $this->createPackage('foo/bar3', array('foo/bar4')),
+                    $this->createPackage('foo/bar4', array()),
+                ),
+                array(
+                    'foo/bar4',
+                    'foo/bar2',
+                    'foo/bar1',
+                    'foo/bar3',
+                ),
+            ),
+            'package is required by many, but requires one other' => array(
+                array(
+                    $this->createPackage('foo/bar1', array('foo/bar3')),
+                    $this->createPackage('foo/bar2', array('foo/bar3')),
+                    $this->createPackage('foo/bar3', array('foo/bar4')),
+                    $this->createPackage('foo/bar4', array()),
+                    $this->createPackage('foo/bar5', array('foo/bar3')),
+                    $this->createPackage('foo/bar6', array('foo/bar3')),
+                ),
+                array(
+                    'foo/bar4',
+                    'foo/bar3',
+                    'foo/bar1',
+                    'foo/bar2',
+                    'foo/bar5',
+                    'foo/bar6',
+                ),
+            ),
+            'one package has many requires' => array(
+                array(
+                    $this->createPackage('foo/bar1', array('foo/bar2')),
+                    $this->createPackage('foo/bar2', array()),
+                    $this->createPackage('foo/bar3', array('foo/bar4')),
+                    $this->createPackage('foo/bar4', array()),
+                    $this->createPackage('foo/bar5', array('foo/bar2')),
+                    $this->createPackage('foo/bar6', array('foo/bar2')),
+                ),
+                array(
+                    'foo/bar2',
+                    'foo/bar4',
+                    'foo/bar1',
+                    'foo/bar3',
+                    'foo/bar5',
+                    'foo/bar6',
+                ),
+            ),
+        );
+    }
+
+    /**
+     * @dataProvider sortingOrdersDependenciesHigherThanPackageDataProvider
+     * @param array $packages
+     * @param array $expectedOrderedList
+     */
+    public function testSortingOrdersDependenciesHigherThanPackage($packages, $expectedOrderedList)
+    {
+        $sortedPackages = PackageSorter::sortPackages($packages);
+        $sortedPackageNames = array_map(function ($package) { return $package->getName(); }, $sortedPackages);
+
+        self::assertSame($expectedOrderedList, $sortedPackageNames);
+    }
+
+    private function createPackage($name, $requires)
+    {
+        $package = new Package($name, '1.0.0.0', '1.0.0');
+
+        $links = array();
+        foreach ($requires as $requireName) {
+            $links[] = new Link($package->getName(), $requireName);
+        }
+        $package->setRequires($links);
+
+        return $package;
+    }
+}