Allow modules to live outside of app/code directory

app/etc/di.xml

@@ -44,6 +44,7 @@
     <preference for="Magento\Framework\Config\CacheInterface" type="Magento\Framework\App\Cache\Type\Config" />
     <preference for="Magento\Framework\Config\ValidationStateInterface" type="Magento\Framework\App\Arguments\ValidationState" />
     <preference for="Magento\Framework\Module\ModuleListInterface" type="Magento\Framework\Module\ModuleList" />
+    <preference for="Magento\Framework\Module\ModuleRegistryInterface" type="Magento\Framework\Module\Registrar" />
     <preference for="Magento\Framework\Event\ConfigInterface" type="Magento\Framework\Event\Config" />
     <preference for="Magento\Framework\Event\InvokerInterface" type="Magento\Framework\Event\Invoker\InvokerDefault" />
     <preference for="Magento\Framework\Interception\PluginListInterface" type="Magento\Framework\Interception\PluginList\PluginList" />
@@ -1075,6 +1076,11 @@
             <argument name="overriddenBaseFiles" xsi:type="object">lessFileOverriddenBase</argument>
         </arguments>
     </type>
+    <type name="Magento\Framework\Module\ModuleList\Loader">
+        <arguments>
+            <argument name="filesystemDriver" xsi:type="object">Magento\Framework\Filesystem\Driver\File</argument>
+        </arguments>
+    </type>
     <type name="Magento\Framework\Module\Setup\MigrationData">
         <arguments>
             <argument name="data" xsi:type="array">

dev/tests/integration/testsuite/Magento/Setup/Console/Command/_files/expected/circular.csv

@@ -2,8 +2,8 @@
 "","2"
 
 "Circular dependencies for each module:",""
-"magento/module-a","1"
-"magento/module-a->magento/module-b->magento/module-a"
-
 "magento/module-b","1"
 "magento/module-b->magento/module-a->magento/module-b"
+
+"magento/module-a","1"
+"magento/module-a->magento/module-b->magento/module-a"

dev/tests/integration/testsuite/Magento/Setup/Console/Command/_files/expected/framework.csv

@@ -2,8 +2,8 @@
 "","2"
 
 "Dependencies for each module:",""
-"Magento\A","1"
+"Magento\B","1"
 " -- Magento\Framework","1"
 
-"Magento\B","1"
+"Magento\A","1"
 " -- Magento\Framework","1"

dev/tests/integration/testsuite/Magento/Setup/Console/Command/_files/expected/modules.csv

@@ -2,8 +2,8 @@
 "Total number of dependencies","2","2","0"
 
 "Dependencies for each module:","All","Hard","Soft"
-"magento/module-a","1","1","0"
-" -- magento/module-b","","1","0"
-
 "magento/module-b","1","1","0"
 " -- magento/module-a","","1","0"
+
+"magento/module-a","1","1","0"
+" -- magento/module-b","","1","0"

lib/internal/Magento/Framework/Module/Dir.php

@@ -10,6 +10,8 @@
 use Magento\Framework\App\Filesystem\DirectoryList;
 use Magento\Framework\Filesystem;
 use Magento\Framework\Filesystem\Directory\ReadInterface;
+use Magento\Framework\Stdlib\String as StringHelper;
+use Magento\Framework\Module\ModuleRegistryInterface;
 
 class Dir
 {
@@ -25,14 +27,26 @@ class Dir
      */
     protected $_string;
 
+    /**
+     * Module registry
+     *
+     * @var ModuleRegistryInterface
+     */
+    private $moduleRegistry;
+
     /**
      * @param Filesystem $filesystem
-     * @param \Magento\Framework\Stdlib\String $string
+     * @param StringHelper $string
+     * @param ModuleRegistryInterface $moduleRegistry
      */
-    public function __construct(Filesystem $filesystem, \Magento\Framework\Stdlib\String $string)
-    {
+    public function __construct(
+        Filesystem $filesystem,
+        StringHelper $string,
+        ModuleRegistryInterface $moduleRegistry
+    ) {
         $this->_modulesDirectory = $filesystem->getDirectoryRead(DirectoryList::MODULES);
         $this->_string = $string;
+        $this->moduleRegistry = $moduleRegistry;
     }
 
     /**
@@ -45,16 +59,18 @@ public function __construct(Filesystem $filesystem, \Magento\Framework\Stdlib\St
      */
     public function getDir($moduleName, $type = '')
     {
-        $path = $this->_string->upperCaseWords($moduleName, '_', '/');
+        if (null === $path = $this->moduleRegistry->getModulePath($moduleName)) {
+            $relativePath = $this->_string->upperCaseWords($moduleName, '_', '/');
+            $path = $this->_modulesDirectory->getAbsolutePath($relativePath);
+        }
+
         if ($type) {
             if (!in_array($type, ['etc', 'i18n', 'view', 'Controller'])) {
                 throw new \InvalidArgumentException("Directory type '{$type}' is not recognized.");
             }
             $path .= '/' . $type;
         }
 
-        $result = $this->_modulesDirectory->getAbsolutePath($path);
-
-        return $result;
+        return $path;
     }
 }

lib/internal/Magento/Framework/Module/ModuleList/Loader.php

@@ -10,6 +10,8 @@
 use Magento\Framework\Filesystem;
 use Magento\Framework\Module\Declaration\Converter\Dom;
 use Magento\Framework\Xml\Parser;
+use Magento\Framework\Module\ModuleRegistryInterface;
+use Magento\Framework\Filesystem\DriverInterface;
 
 /**
  * Loader of module list information from the filesystem
@@ -37,19 +39,42 @@ class Loader
      */
     private $parser;
 
+    /**
+     * Module registry
+     *
+     * @var ModuleRegistryInterface
+     */
+    private $moduleRegistry;
+
+    /**
+     * Filesystem driver to allow reading of module.xml files which live outside of app/code
+     *
+     * @var DriverInterface
+     */
+    private $filesystemDriver;
+
     /**
      * Constructor
      *
      * @param Filesystem $filesystem
      * @param Dom $converter
      * @param Parser $parser
+     * @param ModuleRegistryInterface $moduleRegistry
+     * @param DriverInterface $filesystemDriver
      */
-    public function __construct(Filesystem $filesystem, Dom $converter, Parser $parser)
-    {
+    public function __construct(
+        Filesystem $filesystem,
+        Dom $converter,
+        Parser $parser,
+        ModuleRegistryInterface $moduleRegistry,
+        DriverInterface $filesystemDriver
+    ) {
         $this->filesystem = $filesystem;
         $this->converter = $converter;
         $this->parser = $parser;
         $this->parser->initErrorHandler();
+        $this->moduleRegistry = $moduleRegistry;
+        $this->filesystemDriver = $filesystemDriver;
     }
 
     /**
@@ -61,10 +86,7 @@ public function __construct(Filesystem $filesystem, Dom $converter, Parser $pars
     public function load()
     {
         $result = [];
-        $dir = $this->filesystem->getDirectoryRead(DirectoryList::MODULES);
-        foreach ($dir->search('*/*/etc/module.xml') as $file) {
-            $contents = $dir->readFile($file);
-
+        foreach ($this->getModuleConfigs() as $contents) {
             try {
                 $this->parser->loadXML($contents);
             } catch (\Magento\Framework\Exception\LocalizedException $e) {
@@ -84,6 +106,26 @@ public function load()
         return $this->sortBySequence($result);
     }
 
+    /**
+     * Returns a traversable yielding content of all module.xml files
+     *
+     * @return \Traversable
+     *
+     * @author Josh Di Fabio <[email protected]>
+     */
+    private function getModuleConfigs()
+    {
+        $modulesDir = $this->filesystem->getDirectoryRead(DirectoryList::MODULES);
+        foreach ($modulesDir->search('*/*/etc/module.xml') as $filePath) {
+            yield $modulesDir->readFile($filePath);
+        }
+
+        foreach ($this->moduleRegistry->getModulePaths() as $modulePath) {
+            $filePath =  str_replace(['\\', '/'], DIRECTORY_SEPARATOR, "$modulePath/etc/module.xml");
+            yield $this->filesystemDriver->fileGetContents($filePath);
+        }
+    }
+
     /**
      * Sort the list of modules using "sequence" key in meta-information
      *

lib/internal/Magento/Framework/Module/ModuleRegistryInterface.php

@@ -0,0 +1,27 @@
+<?php
+/**
+ * Copyright © 2015 Magento. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\Framework\Module;
+
+/**
+ * @author Josh Di Fabio <[email protected]>
+ */
+interface ModuleRegistryInterface
+{
+    /**
+     * Get list of Magento module paths
+     *
+     * Returns an array where key is fully-qualified module name and value is absolute path to module
+     *
+     * @return array
+     */
+    public function getModulePaths();
+
+    /**
+     * @param string $moduleName
+     * @return null|string
+     */
+    public function getModulePath($moduleName);
+}

lib/internal/Magento/Framework/Module/Registrar.php

@@ -0,0 +1,48 @@
+<?php
+/**
+ * Copyright © 2015 Magento. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\Framework\Module;
+
+/**
+ * Provides ability to statically register modules which do not reside in the modules directory
+ *
+ * @author Josh Di Fabio <[email protected]>
+ */
+class Registrar implements ModuleRegistryInterface
+{
+    /**
+     * Paths to modules
+     *
+     * @var string[]
+     */
+    private static $modulePaths = [];
+
+    /**
+     * Sets the location of a module. Necessary for modules which do not reside in modules directory
+     *
+     * @param string $moduleName Fully-qualified module name
+     * @param string $path Absolute file path to the module
+     */
+    public static function registerModule($moduleName, $path)
+    {
+        self::$modulePaths[$moduleName] = $path;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getModulePaths()
+    {
+        return self::$modulePaths;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getModulePath($moduleName)
+    {
+        return isset(self::$modulePaths[$moduleName]) ? self::$modulePaths[$moduleName] : null;
+    }
+}

lib/internal/Magento/Framework/Module/Test/Unit/DirTest.php

@@ -27,6 +27,11 @@ class DirTest extends \PHPUnit_Framework_TestCase
      */
     protected $directoryMock;
 
+    /**
+     * @var \Magento\Framework\Module\ModuleRegistryInterface|\PHPUnit_Framework_MockObject_MockObject
+     */
+    protected $moduleRegistryMock;
+
     protected function setUp()
     {
         $this->filesystemMock = $this->getMock('Magento\Framework\Filesystem', [], [], '', false, false);
@@ -39,8 +44,14 @@ protected function setUp()
             false
         );
         $this->_stringMock = $this->getMock('Magento\Framework\Stdlib\String', [], [], '', false, false);
-
-        $this->_stringMock->expects($this->once())->method('upperCaseWords')->will($this->returnValue('Test/Module'));
+        $this->moduleRegistryMock = $this->getMock(
+            'Magento\Framework\Module\ModuleRegistryInterface',
+            [],
+            [],
+            '',
+            false,
+            false
+        );
 
         $this->filesystemMock->expects(
             $this->once()
@@ -50,11 +61,27 @@ protected function setUp()
             $this->returnValue($this->directoryMock)
         );
 
-        $this->_model = new \Magento\Framework\Module\Dir($this->filesystemMock, $this->_stringMock);
+        $this->_model = new \Magento\Framework\Module\Dir(
+            $this->filesystemMock,
+            $this->_stringMock,
+            $this->moduleRegistryMock
+        );
     }
 
     public function testGetDirModuleRoot()
     {
+        $this->moduleRegistryMock->expects(
+            $this->once()
+        )->method(
+            'getModulePath'
+        )->with(
+            'Test_Module'
+        )->will(
+            $this->returnValue(null)
+        );
+
+        $this->_stringMock->expects($this->once())->method('upperCaseWords')->will($this->returnValue('Test/Module'));
+
         $this->directoryMock->expects(
             $this->once()
         )->method(
@@ -64,20 +91,39 @@ public function testGetDirModuleRoot()
         )->will(
             $this->returnValue('/Test/Module')
         );
+
         $this->assertEquals('/Test/Module', $this->_model->getDir('Test_Module'));
     }
 
+    public function testGetDirModuleRootFromResolver()
+    {
+        $this->moduleRegistryMock->expects(
+            $this->once()
+        )->method(
+            'getModulePath'
+        )->with(
+            'Test_Module2'
+        )->will(
+            $this->returnValue('/path/to/module')
+        );
+
+        $this->assertEquals('/path/to/module', $this->_model->getDir('Test_Module2'));
+    }
+
     public function testGetDirModuleSubDir()
     {
+        $this->_stringMock->expects($this->once())->method('upperCaseWords')->will($this->returnValue('Test/Module'));
+
         $this->directoryMock->expects(
             $this->once()
         )->method(
             'getAbsolutePath'
         )->with(
-            'Test/Module/etc'
+            'Test/Module'
         )->will(
-            $this->returnValue('/Test/Module/etc')
+            $this->returnValue('/Test/Module')
         );
+
         $this->assertEquals('/Test/Module/etc', $this->_model->getDir('Test_Module', 'etc'));
     }
 
@@ -87,6 +133,8 @@ public function testGetDirModuleSubDir()
      */
     public function testGetDirModuleSubDirUnknown()
     {
+        $this->_stringMock->expects($this->once())->method('upperCaseWords')->will($this->returnValue('Test/Module'));
+
         $this->_model->getDir('Test_Module', 'unknown');
     }
 }