class HelpTopicsSyntaxTest

class HelpTopicsSyntaxTest extends BrowserTestBase {
    use DeprecatedModulesTestTrait;
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'help',
        'help_topics',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'classy';
    
    /**
     * Tests that all Core help topics can be rendered and have good syntax.
     */
    public function testHelpTopics() {
        $this->drupalLogin($this->rootUser);
        // Enable all modules and themes, so that all routes mentioned in topics
        // will be defined.
        $module_directories = $this->listDirectories('module');
        $modules_to_install = array_keys($module_directories);
        $modules_to_install = $this->removeDeprecatedModules($modules_to_install);
        \Drupal::service('module_installer')->install($modules_to_install);
        $theme_directories = $this->listDirectories('theme');
        \Drupal::service('theme_installer')->install(array_keys($theme_directories));
        $directories = $module_directories + $theme_directories + $this->listDirectories('profile');
        $directories['core'] = \Drupal::service('app.root') . '/core/help_topics';
        $directories['bad_help_topics'] = \Drupal::service('extension.list.module')->getPath('help_topics_test') . '/bad_help_topics/syntax/';
        // Filter out directories outside of core. If you want to run this test
        // on a contrib/custom module, remove the next line.
        $directories = array_filter($directories, function ($directory) {
            return strpos($directory, 'core') === 0;
        });
        // Verify that a few key modules, themes, and profiles are listed, so that
        // we can be certain our directory list is complete and we will be testing
        // all existing help topics. If these lines in the test fail in the future,
        // it is probably because something we chose to list here is being removed.
        // Substitute another item of the same type that still exists, so that this
        // test can continue.
        $this->assertArrayHasKey('system', $directories, 'System module is being scanned');
        $this->assertArrayHasKey('help', $directories, 'Help module is being scanned');
        $this->assertArrayHasKey('seven', $directories, 'Seven theme is being scanned');
        $this->assertArrayHasKey('standard', $directories, 'Standard profile is being scanned');
        $definitions = (new HelpTopicDiscovery($directories))->getDefinitions();
        $this->assertGreaterThan(0, count($definitions), 'At least 1 topic was found');
        // Test each topic for compliance with standards, or for failing in the
        // right way.
        foreach (array_keys($definitions) as $id) {
            if (strpos($id, 'bad_help_topics.') === 0) {
                $this->verifyBadTopic($id, $definitions);
            }
            else {
                $this->verifyTopic($id, $definitions);
            }
        }
    }
    
    /**
     * Verifies rendering and standards compliance of one help topic.
     *
     * @param string $id
     *   ID of the topic to verify.
     * @param array $definitions
     *   Array of all topic definitions, keyed by ID.
     * @param int $response
     *   Expected response from visiting the page for the topic.
     */
    protected function verifyTopic($id, $definitions, $response = 200) {
        $definition = $definitions[$id];
        // Visit the URL for the topic.
        $this->drupalGet('admin/help/topic/' . $id);
        // Verify the title and response.
        $session = $this->assertSession();
        $session->statusCodeEquals($response);
        if ($response == 200) {
            $session->titleEquals($definition['label'] . ' | Drupal');
        }
        // Verify that all the related topics exist. Also check to see if any of
        // them are top-level (we will need that in the next section).
        $has_top_level_related = FALSE;
        if (isset($definition['related'])) {
            foreach ($definition['related'] as $related_id) {
                $this->assertArrayHasKey($related_id, $definitions, 'Topic ' . $id . ' is only related to topics that exist (' . $related_id . ')');
                $has_top_level_related = $has_top_level_related || !empty($definitions[$related_id]['top_level']);
            }
        }
        // Verify this is either top-level or related to a top-level topic.
        $this->assertTrue(!empty($definition['top_level']) || $has_top_level_related, 'Topic ' . $id . ' is either top-level or related to at least one other top-level topic');
        // Verify that the label is not empty.
        $this->assertNotEmpty($definition['label'], 'Topic ' . $id . ' has a non-empty label');
        // Read in the file so we can run some tests on that.
        $body = file_get_contents($definition[HelpTopicDiscovery::FILE_KEY]);
        $this->assertNotEmpty($body, 'Topic ' . $id . ' has a non-empty Twig file');
        // Remove the front matter data (already tested above), and Twig set and
        // variable printouts from the file.
        $body = preg_replace('|---.*---|sU', '', $body);
        $body = preg_replace('|\\{\\{.*\\}\\}|sU', '', $body);
        $body = preg_replace('|\\{\\% set.*\\%\\}|sU', '', $body);
        $body = trim($body);
        $this->assertNotEmpty($body, 'Topic ' . $id . ' Twig file contains some text outside of front matter');
        // Verify that if we remove all the translated text, whitespace, and
        // HTML tags, there is nothing left (that is, all text is translated).
        $text = preg_replace('|\\{\\% trans \\%\\}.*\\{\\% endtrans \\%\\}|sU', '', $body);
        $text = strip_tags($text);
        $text = preg_replace('|\\s+|', '', $text);
        $this->assertEmpty($text, 'Topic ' . $id . ' Twig file has all of its text translated');
        // Load the topic body as HTML and verify that it parses.
        $doc = new \DOMDocument();
        $doc->strictErrorChecking = TRUE;
        $doc->validateOnParse = TRUE;
        libxml_use_internal_errors(TRUE);
        if (!$doc->loadHTML($body)) {
            foreach (libxml_get_errors() as $error) {
                $this->fail($error->message);
            }
            libxml_clear_errors();
        }
        // Check for headings hierarchy.
        $levels = [
            1,
            2,
            3,
            4,
            5,
            6,
        ];
        foreach ($levels as $level) {
            $num_headings[$level] = $doc->getElementsByTagName('h' . $level)->length;
            if ($level == 1) {
                $this->assertSame(0, $num_headings[1], 'Topic ' . $id . ' has no H1 tag');
                // Set num_headings to 1 for this level, so the rest of the hierarchy
                // can be tested using simpler code.
                $num_headings[1] = 1;
            }
            else {
                // We should either not have this heading, or if we do have one at this
                // level, we should also have the next-smaller level. That is, if we
                // have an h3, we should have also had an h2.
                $this->assertTrue($num_headings[$level - 1] > 0 || $num_headings[$level] == 0, 'Topic ' . $id . ' has the correct H2-H6 heading hierarchy');
            }
        }
    }
    
    /**
     * Verifies that a bad topic fails in the expected way.
     *
     * @param string $id
     *   ID of the topic to verify. It should start with "bad_help_topics.".
     * @param array $definitions
     *   Array of all topic definitions, keyed by ID.
     */
    protected function verifyBadTopic($id, $definitions) {
        $bad_topic_type = substr($id, 16);
        // Topics should fail verifyTopic() in specific ways.
        try {
            $this->verifyTopic($id, $definitions, 404);
        } catch (ExpectationFailedException $e) {
            $message = $e->getMessage();
            switch ($bad_topic_type) {
                case 'related':
                    $this->assertStringContainsString('only related to topics that exist', $message);
                    break;
                case 'bad_html':
                    $this->assertStringContainsString('Unexpected end tag', $message);
                    break;
                case 'top_level':
                    $this->assertStringContainsString('is either top-level or related to at least one other top-level topic', $message);
                    break;
                case 'empty':
                    $this->assertStringContainsString('contains some text outside of front matter', $message);
                    break;
                case 'translated':
                    $this->assertStringContainsString('Twig file has all of its text translated', $message);
                    break;
                case 'h1':
                    $this->assertStringContainsString('has no H1 tag', $message);
                    break;
                case 'hierarchy':
                    $this->assertStringContainsString('has the correct H2-H6 heading hierarchy', $message);
                    break;
                default:
                    // This was an unexpected error.
                    throw $e;
            }
        }
    }
    
    /**
     * Lists the extension help topic directories of a certain type.
     *
     * @param string $type
     *   The type of extension to list: module, theme, or profile.
     *
     * @return string[]
     *   An array of all of the help topic directories for this type of
     *   extension, keyed by extension short name.
     */
    protected function listDirectories($type) {
        $directories = [];
        // Find the extensions of this type, even if they are not installed, but
        // excluding test ones.
        $lister = \Drupal::service('extension.list.' . $type);
        foreach (array_keys($lister->getAllAvailableInfo()) as $name) {
            $path = $lister->getPath($name);
            // You can tell test modules because they are in package 'Testing', but
            // test themes are only known by being found in test directories. So...
            // exclude things in test directories.
            if (strpos($path, '/tests') === FALSE && strpos($path, '/testing') === FALSE) {
                $directories[$name] = $path . '/help_topics';
            }
        }
        return $directories;
    }

}