class TestDiscovery

class TestDiscovery {
    
    /**
     * The class loader.
     *
     * @var \Composer\Autoload\ClassLoader
     */
    protected $classLoader;
    
    /**
     * Statically cached list of test classes.
     *
     * @var array
     */
    protected $testClasses;
    
    /**
     * Cached map of all test namespaces to respective directories.
     *
     * @var array
     */
    protected $testNamespaces;
    
    /**
     * Cached list of all available extension names, keyed by extension type.
     *
     * @var array
     */
    protected $availableExtensions;
    
    /**
     * The app root.
     *
     * @var string
     */
    protected $root;
    
    /**
     * Constructs a new test discovery.
     *
     * @param string $root
     *   The app root.
     * @param $class_loader
     *   The class loader. Normally Composer's ClassLoader, as included by the
     *   front controller, but may also be decorated; e.g.,
     *   \Symfony\Component\ClassLoader\ApcClassLoader.
     */
    public function __construct($root, $class_loader) {
        $this->root = $root;
        $this->classLoader = $class_loader;
    }
    
    /**
     * Registers test namespaces of all extensions and core test classes.
     *
     * @return array
     *   An associative array whose keys are PSR-4 namespace prefixes and whose
     *   values are directory names.
     */
    public function registerTestNamespaces() {
        if (isset($this->testNamespaces)) {
            return $this->testNamespaces;
        }
        $this->testNamespaces = [];
        $existing = $this->classLoader
            ->getPrefixesPsr4();
        // Add PHPUnit test namespaces of Drupal core.
        $this->testNamespaces['Drupal\\Tests\\'] = [
            $this->root . '/core/tests/Drupal/Tests',
        ];
        $this->testNamespaces['Drupal\\BuildTests\\'] = [
            $this->root . '/core/tests/Drupal/BuildTests',
        ];
        $this->testNamespaces['Drupal\\KernelTests\\'] = [
            $this->root . '/core/tests/Drupal/KernelTests',
        ];
        $this->testNamespaces['Drupal\\FunctionalTests\\'] = [
            $this->root . '/core/tests/Drupal/FunctionalTests',
        ];
        $this->testNamespaces['Drupal\\FunctionalJavascriptTests\\'] = [
            $this->root . '/core/tests/Drupal/FunctionalJavascriptTests',
        ];
        $this->testNamespaces['Drupal\\TestTools\\'] = [
            $this->root . '/core/tests/Drupal/TestTools',
        ];
        $this->availableExtensions = [];
        foreach ($this->getExtensions() as $name => $extension) {
            $this->availableExtensions[$extension->getType()][$name] = $name;
            $base_path = $this->root . '/' . $extension->getPath();
            // Add namespace of disabled/uninstalled extensions.
            if (!isset($existing["Drupal\\{$name}\\"])) {
                $this->classLoader
                    ->addPsr4("Drupal\\{$name}\\", "{$base_path}/src");
            }
            // Add Simpletest test namespace.
            $this->testNamespaces["Drupal\\{$name}\\Tests\\"][] = "{$base_path}/src/Tests";
            // Add PHPUnit test namespaces.
            $this->testNamespaces["Drupal\\Tests\\{$name}\\Unit\\"][] = "{$base_path}/tests/src/Unit";
            $this->testNamespaces["Drupal\\Tests\\{$name}\\Kernel\\"][] = "{$base_path}/tests/src/Kernel";
            $this->testNamespaces["Drupal\\Tests\\{$name}\\Functional\\"][] = "{$base_path}/tests/src/Functional";
            $this->testNamespaces["Drupal\\Tests\\{$name}\\Build\\"][] = "{$base_path}/tests/src/Build";
            $this->testNamespaces["Drupal\\Tests\\{$name}\\FunctionalJavascript\\"][] = "{$base_path}/tests/src/FunctionalJavascript";
            // Add discovery for traits which are shared between different test
            // suites.
            $this->testNamespaces["Drupal\\Tests\\{$name}\\Traits\\"][] = "{$base_path}/tests/src/Traits";
        }
        foreach ($this->testNamespaces as $prefix => $paths) {
            $this->classLoader
                ->addPsr4($prefix, $paths);
        }
        $loader = (require __DIR__ . '/../../../../../autoload.php');
        // Ensure we have a valid TestCase class.
        ClassWriter::mutateTestBase($loader);
        return $this->testNamespaces;
    }
    
    /**
     * Discovers all available tests in all extensions.
     *
     * @param string $extension
     *   (optional) The name of an extension to limit discovery to; e.g., 'node'.
     * @param string[] $types
     *   An array of included test types.
     *
     * @return array
     *   An array of tests keyed by the group name. If a test is annotated to
     *   belong to multiple groups, it will appear under all group keys it belongs
     *   to.
     *
     * @code
     *     $groups['block'] => array(
     *       'Drupal\Tests\block\Functional\BlockTest' => array(
     *         'name' => 'Drupal\Tests\block\Functional\BlockTest',
     *         'description' => 'Tests block UI CRUD functionality.',
     *         'group' => 'block',
     *         'groups' => ['block', 'group2', 'group3'],
     *       ),
     *     );
     * @endcode
     *
     * @todo Remove singular grouping; retain list of groups in 'group' key.
     * @see https://www.drupal.org/node/2296615
     */
    public function getTestClasses($extension = NULL, array $types = []) {
        if (!isset($extension) && empty($types)) {
            if (!empty($this->testClasses)) {
                return $this->testClasses;
            }
        }
        $list = [];
        $classmap = $this->findAllClassFiles($extension);
        // Prevent expensive class loader lookups for each reflected test class by
        // registering the complete classmap of test classes to the class loader.
        // This also ensures that test classes are loaded from the discovered
        // pathnames; a namespace/classname mismatch will throw an exception.
        $this->classLoader
            ->addClassMap($classmap);
        foreach ($classmap as $classname => $pathname) {
            $finder = MockFileFinder::create($pathname);
            $parser = new StaticReflectionParser($classname, $finder, TRUE);
            try {
                $info = static::getTestInfo($classname, $parser->getDocComment());
            } catch (MissingGroupException $e) {
                // If the class name ends in Test and is not a migrate table dump.
                if (preg_match('/Test$/', $classname) && strpos($classname, 'migrate_drupal\\Tests\\Table') === FALSE) {
                    throw $e;
                }
                // If the class is @group annotation just skip it. Most likely it is an
                // abstract class, trait or test fixture.
                continue;
            }
            // Skip this test class if it is a Simpletest-based test and requires
            // unavailable modules. TestDiscovery should not filter out module
            // requirements for PHPUnit-based test classes.
            // @todo Move this behavior to \Drupal\simpletest\TestBase so tests can be
            //   marked as skipped, instead.
            // @see https://www.drupal.org/node/1273478
            if ($info['type'] == 'Simpletest') {
                if (!empty($info['requires']['module'])) {
                    if (array_diff($info['requires']['module'], $this->availableExtensions['module'])) {
                        continue;
                    }
                }
            }
            foreach ($info['groups'] as $group) {
                $list[$group][$classname] = $info;
            }
        }
        // Sort the groups and tests within the groups by name.
        uksort($list, 'strnatcasecmp');
        foreach ($list as &$tests) {
            uksort($tests, 'strnatcasecmp');
        }
        if (!isset($extension) && empty($types)) {
            $this->testClasses = $list;
        }
        if ($types) {
            $list = NestedArray::filter($list, function ($element) use ($types) {
                return !(is_array($element) && isset($element['type']) && !in_array($element['type'], $types));
            });
        }
        return $list;
    }
    
    /**
     * Discovers all class files in all available extensions.
     *
     * @param string $extension
     *   (optional) The name of an extension to limit discovery to; e.g., 'node'.
     *
     * @return array
     *   A classmap containing all discovered class files; i.e., a map of
     *   fully-qualified classnames to pathnames.
     */
    public function findAllClassFiles($extension = NULL) {
        $classmap = [];
        $namespaces = $this->registerTestNamespaces();
        if (isset($extension)) {
            // Include tests in the \Drupal\Tests\{$extension} namespace.
            $pattern = "/Drupal\\\\(Tests\\\\)?{$extension}\\\\/";
            $namespaces = array_intersect_key($namespaces, array_flip(preg_grep($pattern, array_keys($namespaces))));
        }
        foreach ($namespaces as $namespace => $paths) {
            foreach ($paths as $path) {
                if (!is_dir($path)) {
                    continue;
                }
                $classmap += static::scanDirectory($namespace, $path);
            }
        }
        return $classmap;
    }
    
    /**
     * Scans a given directory for class files.
     *
     * @param string $namespace_prefix
     *   The namespace prefix to use for discovered classes. Must contain a
     *   trailing namespace separator (backslash).
     *   For example: 'Drupal\\node\\Tests\\'
     * @param string $path
     *   The directory path to scan.
     *   For example: '/path/to/drupal/core/modules/node/tests/src'
     *
     * @return array
     *   An associative array whose keys are fully-qualified class names and whose
     *   values are corresponding filesystem pathnames.
     *
     * @throws \InvalidArgumentException
     *   If $namespace_prefix does not end in a namespace separator (backslash).
     *
     * @todo Limit to '*Test.php' files (~10% less files to reflect/introspect).
     * @see https://www.drupal.org/node/2296635
     */
    public static function scanDirectory($namespace_prefix, $path) {
        if (substr($namespace_prefix, -1) !== '\\') {
            throw new \InvalidArgumentException("Namespace prefix for {$path} must contain a trailing namespace separator.");
        }
        $flags = \FilesystemIterator::UNIX_PATHS;
        $flags |= \FilesystemIterator::SKIP_DOTS;
        $flags |= \FilesystemIterator::FOLLOW_SYMLINKS;
        $flags |= \FilesystemIterator::CURRENT_AS_SELF;
        $flags |= \FilesystemIterator::KEY_AS_FILENAME;
        $iterator = new \RecursiveDirectoryIterator($path, $flags);
        $filter = new \RecursiveCallbackFilterIterator($iterator, function ($current, $file_name, $iterator) {
            if ($iterator->hasChildren()) {
                return TRUE;
            }
            // We don't want to discover abstract TestBase classes, traits or
            // interfaces. They can be deprecated and will call @trigger_error()
            // during discovery.
            return substr($file_name, -4) === '.php' && substr($file_name, -12) !== 'TestBase.php' && substr($file_name, -9) !== 'Trait.php' && substr($file_name, -13) !== 'Interface.php';
        });
        $files = new \RecursiveIteratorIterator($filter);
        $classes = [];
        foreach ($files as $fileinfo) {
            $class = $namespace_prefix;
            if ('' !== ($subpath = $fileinfo->getSubPath())) {
                $class .= strtr($subpath, '/', '\\') . '\\';
            }
            $class .= $fileinfo->getBasename('.php');
            $classes[$class] = $fileinfo->getPathname();
        }
        return $classes;
    }
    
    /**
     * Retrieves information about a test class for UI purposes.
     *
     * @param string $classname
     *   The test classname.
     * @param string $doc_comment
     *   (optional) The class PHPDoc comment. If not passed in reflection will be
     *   used but this is very expensive when parsing all the test classes.
     *
     * @return array
     *   An associative array containing:
     *   - name: The test class name.
     *   - description: The test (PHPDoc) summary.
     *   - group: The test's first @group (parsed from PHPDoc annotations).
     *   - groups: All of the test's @group annotations, as an array (parsed from
     *     PHPDoc annotations).
     *   - requires: An associative array containing test requirements parsed from
     *     PHPDoc annotations:
     *     - module: List of Drupal module extension names the test depends on.
     *
     * @throws \Drupal\simpletest\Exception\MissingGroupException
     *   If the class does not have a @group annotation.
     */
    public static function getTestInfo($classname, $doc_comment = NULL) {
        if ($doc_comment === NULL) {
            $reflection = new \ReflectionClass($classname);
            $doc_comment = $reflection->getDocComment();
        }
        $info = [
            'name' => $classname,
        ];
        $annotations = [];
        // Look for annotations, allow an arbitrary amount of spaces before the
        // * but nothing else.
        preg_match_all('/^[ ]*\\* \\@([^\\s]*) (.*$)/m', $doc_comment, $matches);
        if (isset($matches[1])) {
            foreach ($matches[1] as $key => $annotation) {
                // For historical reasons, there is a single-value 'group' result key
                // and a 'groups' key as an array.
                if ($annotation === 'group') {
                    $annotations['groups'][] = $matches[2][$key];
                }
                if (!empty($annotations[$annotation])) {
                    // Only @group is allowed to have more than one annotation, in the
                    // 'groups' key. Other annotations only have one value per key.
                    continue;
                }
                $annotations[$annotation] = $matches[2][$key];
            }
        }
        if (empty($annotations['group'])) {
            // Concrete tests must have a group.
            throw new MissingGroupException(sprintf('Missing @group annotation in %s', $classname));
        }
        $info['group'] = $annotations['group'];
        $info['groups'] = $annotations['groups'];
        // Sort out PHPUnit-runnable tests by type.
        if ($testsuite = static::getPhpunitTestSuite($classname)) {
            $info['type'] = 'PHPUnit-' . $testsuite;
        }
        else {
            $info['type'] = 'Simpletest';
        }
        if (!empty($annotations['coversDefaultClass'])) {
            $info['description'] = 'Tests ' . $annotations['coversDefaultClass'] . '.';
        }
        else {
            $info['description'] = static::parseTestClassSummary($doc_comment);
        }
        if (isset($annotations['dependencies'])) {
            $info['requires']['module'] = array_map('trim', explode(',', $annotations['dependencies']));
        }
        return $info;
    }
    
    /**
     * Parses the phpDoc summary line of a test class.
     *
     * @param string $doc_comment
     *   The documentation comment.
     *
     * @return string
     *   The parsed phpDoc summary line. An empty string is returned if no summary
     *   line can be parsed.
     */
    public static function parseTestClassSummary($doc_comment) {
        // Normalize line endings.
        $doc_comment = preg_replace('/\\r\\n|\\r/', '\\n', $doc_comment);
        // Strip leading and trailing doc block lines.
        $doc_comment = substr($doc_comment, 4, -4);
        $lines = explode("\n", $doc_comment);
        $summary = [];
        // Add every line to the summary until the first empty line or annotation
        // is found.
        foreach ($lines as $line) {
            if (preg_match('/^[ ]*\\*$/', $line) || preg_match('/^[ ]*\\* \\@/', $line)) {
                break;
            }
            $summary[] = trim($line, ' *');
        }
        return implode(' ', $summary);
    }
    
    /**
     * Parses annotations in the phpDoc of a test class.
     *
     * @param \ReflectionClass $class
     *   The reflected test class.
     *
     * @return array
     *   An associative array that contains all annotations on the test class;
     *   typically including:
     *   - group: A list of @group values.
     *   - requires: An associative array of @requires values; e.g.:
     *     - module: A list of Drupal module dependencies that are required to
     *       exist.
     *
     * @see \PHPUnit\Util\Test::parseTestMethodAnnotations()
     * @see http://phpunit.de/manual/current/en/incomplete-and-skipped-tests.html#incomplete-and-skipped-tests.skipping-tests-using-requires
     */
    public static function parseTestClassAnnotations(\ReflectionClass $class) {
        $annotations = Test::parseTestMethodAnnotations($class->getName())['class'];
        // @todo Enhance PHPUnit upstream to allow for custom @requires identifiers.
        // @see \PHPUnit\Util\Test::getRequirements()
        // @todo Add support for 'PHP', 'OS', 'function', 'extension'.
        // @see https://www.drupal.org/node/1273478
        if (isset($annotations['requires'])) {
            foreach ($annotations['requires'] as $i => $value) {
                [
                    $type,
                    $value,
                ] = explode(' ', $value, 2);
                if ($type === 'module') {
                    $annotations['requires']['module'][$value] = $value;
                    unset($annotations['requires'][$i]);
                }
            }
        }
        return $annotations;
    }
    
    /**
     * Determines the phpunit testsuite for a given classname, based on namespace.
     *
     * @param string $classname
     *   The test classname.
     *
     * @return string|false
     *   The testsuite name or FALSE if its not a phpunit test.
     */
    public static function getPhpunitTestSuite($classname) {
        if (preg_match('/Drupal\\\\Tests\\\\(\\w+)\\\\(\\w+)/', $classname, $matches)) {
            // This could be an extension test, in which case the first match will be
            // the extension name. We assume that lower-case strings are module names.
            if (strtolower($matches[1]) == $matches[1]) {
                return $matches[2];
            }
            return 'Unit';
        }
        elseif (preg_match('/Drupal\\\\(\\w*)Tests\\\\/', $classname, $matches)) {
            if ($matches[1] == '') {
                return 'Unit';
            }
            return $matches[1];
        }
        return FALSE;
    }
    
    /**
     * Returns all available extensions.
     *
     * @return \Drupal\Core\Extension\Extension[]
     *   An array of Extension objects, keyed by extension name.
     */
    protected function getExtensions() {
        $listing = new ExtensionDiscovery($this->root);
        // Ensure that tests in all profiles are discovered.
        $listing->setProfileDirectories([]);
        $extensions = $listing->scan('module', TRUE);
        $extensions += $listing->scan('profile', TRUE);
        $extensions += $listing->scan('theme', TRUE);
        return $extensions;
    }

}