[ClassLoader] Added a simplified PSR-0 ClassLoader

The new ClassLoader does not differentiate namespaced classes and
PEAR-like classes like the UniversalClassLoader does as the PEAR
format is a subset of PSR-0.
The new loader registers fallbacks by adding a location for an empty
prefix, as done in Composer. This allows using namespaces map generated
by Composer without any special processing on them.

src/Symfony/Component/ClassLoader/ClassLoader.php

@@ -0,0 +1,185 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\ClassLoader;
+
+/**
+ * ClassLoader implements an PSR-0 class loader
+ *
+ * See https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-0.md
+ *
+ *     $loader = new ClassLoader();
+ *
+ *     // register classes with namespaces
+ *     $loader->add('Symfony\Component', __DIR__.'/component');
+ *     $loader->add('Symfony',           __DIR__.'/framework');
+ *
+ *     // activate the autoloader
+ *     $loader->register();
+ *
+ *     // to enable searching the include path (eg. for PEAR packages)
+ *     $loader->setUseIncludePath(true);
+ *
+ * In this example, if you try to use a class in the Symfony\Component
+ * namespace or one of its children (Symfony\Component\Console for instance),
+ * the autoloader will first look for the class under the component/
+ * directory, and it will then fallback to the framework/ directory if not
+ * found before giving up.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+class ClassLoader
+{
+    private $prefixes = array();
+    private $fallbackDirs = array();
+    private $useIncludePath = false;
+
+    public function getPrefixes()
+    {
+        return $this->prefixes;
+    }
+
+    public function getFallbackDirs()
+    {
+        return $this->fallbackDirs;
+    }
+
+    public function addPrefixes(array $prefixes)
+    {
+        foreach ($prefixes as $prefix => $path) {
+            $this->addPrefix($prefix, $path);
+        }
+    }
+
+    /**
+     * Registers a set of classes
+     *
+     * @param string       $prefix  The classes prefix
+     * @param array|string $paths   The location(s) of the classes
+     */
+    public function addPrefix($prefix, $paths)
+    {
+        if (!$prefix) {
+            foreach ((array) $paths as $path) {
+                $this->fallbackDirs[] = $path;
+            }
+            return;
+        }
+        if (isset($this->prefixes[$prefix])) {
+            $this->prefixes[$prefix] = array_merge(
+                $this->prefixes[$prefix],
+                (array) $paths
+            );
+        } else {
+            $this->prefixes[$prefix] = (array) $paths;
+        }
+    }
+
+    /**
+     * Turns on searching the include for class files.
+     *
+     * @param Boolean $useIncludePath
+     */
+    public function setUseIncludePath($useIncludePath)
+    {
+        $this->useIncludePath = $useIncludePath;
+    }
+
+    /**
+     * Can be used to check if the autoloader uses the include path to check
+     * for classes.
+     *
+     * @return Boolean
+     */
+    public function getUseIncludePath()
+    {
+        return $this->useIncludePath;
+    }
+
+    /**
+     * Registers this instance as an autoloader.
+     *
+     * @param Boolean $prepend Whether to prepend the autoloader or not
+     */
+    public function register($prepend = false)
+    {
+        spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+    }
+
+    /**
+     * Unregisters this instance as an autoloader.
+     */
+    public function unregister()
+    {
+        spl_autoload_unregister(array($this, 'loadClass'));
+    }
+
+    /**
+     * Loads the given class or interface.
+     *
+     * @param string $class The name of the class
+     * @return Boolean|null True, if loaded
+     */
+    public function loadClass($class)
+    {
+        if ($file = $this->findFile($class)) {
+            require $file;
+            return true;
+        }
+    }
+
+    /**
+     * Finds the path to the file where the class is defined.
+     *
+     * @param string $class The name of the class
+     *
+     * @return string|null The path, if found
+     */
+    public function findFile($class)
+    {
+        if ('\\' == $class[0]) {
+            $class = substr($class, 1);
+        }
+
+        if (false !== $pos = strrpos($class, '\\')) {
+            // namespaced class name
+            $classPath = str_replace('\\', DIRECTORY_SEPARATOR, substr($class, 0, $pos)) . DIRECTORY_SEPARATOR;
+            $className = substr($class, $pos + 1);
+        } else {
+            // PEAR-like class name
+            $classPath = null;
+            $className = $class;
+        }
+
+        $classPath .= str_replace('_', DIRECTORY_SEPARATOR, $className) . '.php';
+
+        foreach ($this->prefixes as $prefix => $dirs) {
+            if (0 === strpos($class, $prefix)) {
+                foreach ($dirs as $dir) {
+                    if (file_exists($dir . DIRECTORY_SEPARATOR . $classPath)) {
+                        return $dir . DIRECTORY_SEPARATOR . $classPath;
+                    }
+                }
+            }
+        }
+
+        foreach ($this->fallbackDirs as $dir) {
+            if (file_exists($dir . DIRECTORY_SEPARATOR . $classPath)) {
+                return $dir . DIRECTORY_SEPARATOR . $classPath;
+            }
+        }
+
+        if ($this->useIncludePath && $file = stream_resolve_include_path($classPath)) {
+            return $file;
+        }
+    }
+}

src/Symfony/Component/ClassLoader/Tests/ClassLoaderTest.php

@@ -0,0 +1,163 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\ClassLoader\Tests;
+
+use Symfony\Component\ClassLoader\ClassLoader;
+
+class ClassLoaderTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @dataProvider getLoadClassTests
+     */
+    public function testLoadClass($className, $testClassName, $message)
+    {
+        $loader = new ClassLoader();
+        $loader->addPrefix('Namespaced2\\', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
+        $loader->addPrefix('Pearlike2_', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
+        $loader->loadClass($testClassName);
+        $this->assertTrue(class_exists($className), $message);
+    }
+
+    public function getLoadClassTests()
+    {
+        return array(
+            array('\\Namespaced2\\Foo', 'Namespaced2\\Foo',   '->loadClass() loads Namespaced2\Foo class'),
+            array('\\Pearlike2_Foo',    'Pearlike2_Foo',      '->loadClass() loads Pearlike2_Foo class'),
+            array('\\Namespaced2\\Bar', '\\Namespaced2\\Bar', '->loadClass() loads Namespaced2\Bar class with a leading slash'),
+            array('\\Pearlike2_Bar',    '\\Pearlike2_Bar',    '->loadClass() loads Pearlike2_Bar class with a leading slash'),
+        );
+    }
+
+    public function testUseIncludePath()
+    {
+        $loader = new ClassLoader();
+        $this->assertFalse($loader->getUseIncludePath());
+
+        $this->assertEquals(null, $loader->findFile('Foo'));
+
+        $includePath = get_include_path();
+
+        $loader->setUseIncludePath(true);
+        $this->assertTrue($loader->getUseIncludePath());
+
+        set_include_path(__DIR__.'/Fixtures/includepath' . PATH_SEPARATOR . $includePath);
+
+        $this->assertEquals(__DIR__.DIRECTORY_SEPARATOR.'Fixtures'.DIRECTORY_SEPARATOR.'includepath'.DIRECTORY_SEPARATOR.'Foo.php', $loader->findFile('Foo'));
+
+        set_include_path($includePath);
+    }
+
+    /**
+     * @dataProvider getLoadClassFromFallbackTests
+     */
+    public function testLoadClassFromFallback($className, $testClassName, $message)
+    {
+        $loader = new ClassLoader();
+        $loader->addPrefix('Namespaced2\\', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
+        $loader->addPrefix('Pearlike2_', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
+        $loader->addPrefix('', array(__DIR__.DIRECTORY_SEPARATOR.'Fixtures/fallback'));
+        $loader->loadClass($testClassName);
+        $this->assertTrue(class_exists($className), $message);
+    }
+
+    public function getLoadClassFromFallbackTests()
+    {
+        return array(
+            array('\\Namespaced2\\Baz',    'Namespaced2\\Baz',    '->loadClass() loads Namespaced2\Baz class'),
+            array('\\Pearlike2_Baz',       'Pearlike2_Baz',       '->loadClass() loads Pearlike2_Baz class'),
+            array('\\Namespaced2\\FooBar', 'Namespaced2\\FooBar', '->loadClass() loads Namespaced2\Baz class from fallback dir'),
+            array('\\Pearlike2_FooBar',    'Pearlike2_FooBar',    '->loadClass() loads Pearlike2_Baz class from fallback dir'),
+        );
+    }
+
+    /**
+     * @dataProvider getLoadClassNamespaceCollisionTests
+     */
+    public function testLoadClassNamespaceCollision($namespaces, $className, $message)
+    {
+        $loader = new ClassLoader();
+        $loader->addPrefixes($namespaces);
+
+        $loader->loadClass($className);
+        $this->assertTrue(class_exists($className), $message);
+    }
+
+    public function getLoadClassNamespaceCollisionTests()
+    {
+        return array(
+            array(
+                array(
+                    'NamespaceCollision\\C' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/alpha',
+                    'NamespaceCollision\\C\\B' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/beta',
+                ),
+                'NamespaceCollision\C\Foo',
+                '->loadClass() loads NamespaceCollision\C\Foo from alpha.',
+            ),
+            array(
+                array(
+                    'NamespaceCollision\\C\\B' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/beta',
+                    'NamespaceCollision\\C' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/alpha',
+                ),
+                'NamespaceCollision\C\Bar',
+                '->loadClass() loads NamespaceCollision\C\Bar from alpha.',
+            ),
+            array(
+                array(
+                    'NamespaceCollision\\C' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/alpha',
+                    'NamespaceCollision\\C\\B' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/beta',
+                ),
+                'NamespaceCollision\C\B\Foo',
+                '->loadClass() loads NamespaceCollision\C\B\Foo from beta.',
+            ),
+            array(
+                array(
+                    'NamespaceCollision\\C\\B' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/beta',
+                    'NamespaceCollision\\C' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/alpha',
+                ),
+                'NamespaceCollision\C\B\Bar',
+                '->loadClass() loads NamespaceCollision\C\B\Bar from beta.',
+            ),
+            array(
+                array(
+                    'PrefixCollision_C_' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/alpha',
+                    'PrefixCollision_C_B_' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/beta',
+                ),
+                'PrefixCollision_C_Foo',
+                '->loadClass() loads PrefixCollision_C_Foo from alpha.',
+            ),
+            array(
+                array(
+                    'PrefixCollision_C_B_' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/beta',
+                    'PrefixCollision_C_' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/alpha',
+                ),
+                'PrefixCollision_C_Bar',
+                '->loadClass() loads PrefixCollision_C_Bar from alpha.',
+            ),
+            array(
+                array(
+                    'PrefixCollision_C_' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/alpha',
+                    'PrefixCollision_C_B_' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/beta',
+                ),
+                'PrefixCollision_C_B_Foo',
+                '->loadClass() loads PrefixCollision_C_B_Foo from beta.',
+            ),
+            array(
+                array(
+                    'PrefixCollision_C_B_' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/beta',
+                    'PrefixCollision_C_' => __DIR__.DIRECTORY_SEPARATOR.'Fixtures/alpha',
+                ),
+                'PrefixCollision_C_B_Bar',
+                '->loadClass() loads PrefixCollision_C_B_Bar from beta.',
+            ),
+        );
+    }
+}

src/Symfony/Component/ClassLoader/Tests/ClassMapGeneratorTest.php

@@ -36,6 +36,8 @@ public function getTestCreateMapTests()
             array(__DIR__.'/Fixtures/beta/NamespaceCollision', array(
                 'NamespaceCollision\\A\\B\\Bar' => realpath(__DIR__).'/Fixtures/beta/NamespaceCollision/A/B/Bar.php',
                 'NamespaceCollision\\A\\B\\Foo' => realpath(__DIR__).'/Fixtures/beta/NamespaceCollision/A/B/Foo.php',
+                'NamespaceCollision\\C\\B\\Bar' => realpath(__DIR__).'/Fixtures/beta/NamespaceCollision/C/B/Bar.php',
+                'NamespaceCollision\\C\\B\\Foo' => realpath(__DIR__).'/Fixtures/beta/NamespaceCollision/C/B/Foo.php',
             )),
             array(__DIR__.'/Fixtures/Pearlike', array(
                 'Pearlike_Foo' => realpath(__DIR__).'/Fixtures/Pearlike/Foo.php',
@@ -82,6 +84,8 @@ public function testCreateMapFinderSupport()
         $this->assertEqualsNormalized(array(
             'NamespaceCollision\\A\\B\\Bar' => realpath(__DIR__).'/Fixtures/beta/NamespaceCollision/A/B/Bar.php',
             'NamespaceCollision\\A\\B\\Foo' => realpath(__DIR__).'/Fixtures/beta/NamespaceCollision/A/B/Foo.php',
+            'NamespaceCollision\\C\\B\\Bar' => realpath(__DIR__).'/Fixtures/beta/NamespaceCollision/C/B/Bar.php',
+            'NamespaceCollision\\C\\B\\Foo' => realpath(__DIR__).'/Fixtures/beta/NamespaceCollision/C/B/Foo.php',
         ), ClassMapGenerator::createMap($finder));
     }
 

src/Symfony/Component/ClassLoader/Tests/Fixtures/Namespaced2/Bar.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Namespaced2;
+
+class Bar
+{
+    public static $loaded = true;
+}

src/Symfony/Component/ClassLoader/Tests/Fixtures/Namespaced2/Baz.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Namespaced2;
+
+class Baz
+{
+    public static $loaded = true;
+}

src/Symfony/Component/ClassLoader/Tests/Fixtures/Namespaced2/Foo.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Namespaced2;
+
+class Foo
+{
+    public static $loaded = true;
+}