Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * Testing util classes

 *

 * @package    core

 * @category   test

 * @copyright  2012 Petr Skoda {@link http://skodak.org}

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

abstract class testing_util {

    /**

     * @var string dataroot (likely to be $CFG->dataroot).

     */

    private static $dataroot = null;

    /**

     * @var testing_data_generator

     */

    protected static $generator = null;

    /**

     * @var string current version hash from php files

     */

    protected static $versionhash = null;

    /**

     * @var array original content of all database tables

     */

    protected static $tabledata = null;

    /**

     * @var array original structure of all database tables

     */

    protected static $tablestructure = null;

    /**

     * @var array keep list of sequenceid used in a table.

     */

    private static $tablesequences = [];

    /**

     * @var array list of updated tables.

     */

    public static $tableupdated = [];

    /**

     * @var array original structure of all database tables

     */

    protected static $sequencenames = null;

    /**

     * @var string name of the json file where we store the list of dataroot files to not reset during reset_dataroot.

     */

    private static $originaldatafilesjson = 'originaldatafiles.json';

    /**

     * @var boolean set to true once $originaldatafilesjson file is created.

     */

    private static $originaldatafilesjsonadded = false;

    /**

     * @var int next sequence value for a single test cycle.

     */

    protected static $sequencenextstartingid = null;

    /**

     * Return the name of the JSON file containing the init filenames.

     *

     * @static

     * @return string

     */

    public static function get_originaldatafilesjson() {

        return self::$originaldatafilesjson;

    }

    /**

     * Return the dataroot. It's useful when mocking the dataroot when unit testing this class itself.

     *

     * @static

     * @return string the dataroot.

     */

    public static function get_dataroot() {

        global $CFG;

        // By default it's the test framework dataroot.

        if (empty(self::$dataroot)) {

            self::$dataroot = $CFG->dataroot;

        }

        return self::$dataroot;

    }

    /**

     * Set the dataroot. It's useful when mocking the dataroot when unit testing this class itself.

     *

     * @param string $dataroot the dataroot of the test framework.

     * @static

     */

    public static function set_dataroot($dataroot) {

        self::$dataroot = $dataroot;

    }

    /**

     * Returns the testing framework name

     * @static

     * @return string

     */

    final protected static function get_framework() {

        $classname = get_called_class();

        return substr($classname, 0, strpos($classname, '_'));

    }

    /**

     * Get data generator

     * @static

     * @return testing_data_generator

     */

    public static function get_data_generator() {

        if (is_null(self::$generator)) {

            require_once(__DIR__ . '/../generator/lib.php');

            self::$generator = new testing_data_generator();

        }

        return self::$generator;

    }

    /**

     * Does this site (db and dataroot) appear to be used for production?

     * We try very hard to prevent accidental damage done to production servers!!

     *

     * @static

     * @return bool

     */

    public static function is_test_site() {

        global $DB, $CFG;

        $framework = self::get_framework();

        if (!file_exists(self::get_dataroot() . '/' . $framework . 'testdir.txt')) {

            // This is already tested in bootstrap script,

            // But anyway presence of this file means the dataroot is for testing.

            return false;

        }

        $tables = $DB->get_tables(false);

        if ($tables) {

            if (!$DB->get_manager()->table_exists('config')) {

                return false;

            }

            if (!get_config('core', $framework . 'test')) {

                return false;

            }

        }

        return true;

    }

    /**

     * Returns whether test database and dataroot were created using the current version codebase

     *

     * @return bool

     */

    public static function is_test_data_updated() {

        global $DB;

        $framework = self::get_framework();

        $datarootpath = self::get_dataroot() . '/' . $framework;

        if (!file_exists($datarootpath . '/tabledata.ser') || !file_exists($datarootpath . '/tablestructure.ser')) {

            return false;

        }

        if (!file_exists($datarootpath . '/versionshash.txt')) {

            return false;

        }

        $hash = core_component::get_all_versions_hash();

        $oldhash = file_get_contents($datarootpath . '/versionshash.txt');

        if ($hash !== $oldhash) {

            return false;

        }

        // A direct database request must be used to avoid any possible caching of an older value.

        $dbhash = $DB->get_field('config', 'value', ['name' => $framework . 'test']);

        if ($hash !== $dbhash) {

            return false;

        }

        return true;

    }

    /**

     * Stores the status of the database

     *

     * Serializes the contents and the structure and

     * stores it in the test framework space in dataroot

     */

    protected static function store_database_state() {

        global $DB, $CFG;

        $framework = self::get_framework();

        // Store data for all tables.

        $data = [];

        $structure = [];

        $tables = $DB->get_tables();

        foreach ($tables as $table) {

            $columns = $DB->get_columns($table);

            $structure[$table] = $columns;

            if (isset($columns['id']) && $columns['id']->auto_increment) {

                $data[$table] = $DB->get_records($table, [], 'id ASC');

            } else {

                // There should not be many of these.

                $data[$table] = $DB->get_records($table, []);

            }

        }

        $data = serialize($data);

        $datafile = self::get_dataroot() . '/' . $framework . '/tabledata.ser';

        file_put_contents($datafile, $data);

        testing_fix_file_permissions($datafile);

        $structure = serialize($structure);

        $structurefile = self::get_dataroot() . '/' . $framework . '/tablestructure.ser';

        file_put_contents($structurefile, $structure);

        testing_fix_file_permissions($structurefile);

    }

    /**

     * Stores the version hash in both database and dataroot

     */

    protected static function store_versions_hash() {

        global $CFG;

        $framework = self::get_framework();

        $hash = core_component::get_all_versions_hash();

        // Add test db flag.

        set_config($framework . 'test', $hash);

        // Hash all plugin versions - helps with very fast detection of db structure changes.

        $hashfile = self::get_dataroot() . '/' . $framework . '/versionshash.txt';

        file_put_contents($hashfile, $hash);

        testing_fix_file_permissions($hashfile);

    }

    /**

     * Returns contents of all tables right after installation.

     * @static

     * @return array  $table=>$records

     */

    protected static function get_tabledata() {

        if (!isset(self::$tabledata)) {

            $framework = self::get_framework();

            $datafile = self::get_dataroot() . '/' . $framework . '/tabledata.ser';

            if (!file_exists($datafile)) {

                // Not initialised yet.

                return [];

            }

            $data = file_get_contents($datafile);

            self::$tabledata = unserialize($data);

        }

        if (!is_array(self::$tabledata)) {

            testing_error(

                1,

                'Can not read dataroot/' . $framework . '/tabledata.ser or invalid format, reinitialize test database.',

            );

        }

        return self::$tabledata;

    }

    /**

     * Returns structure of all tables right after installation.

     * @static

     * @return array $table=>$records

     */

    public static function get_tablestructure() {

        if (!isset(self::$tablestructure)) {

            $framework = self::get_framework();

            $structurefile = self::get_dataroot() . '/' . $framework . '/tablestructure.ser';

            if (!file_exists($structurefile)) {

                // Not initialised yet.

                return [];

            }

            $data = file_get_contents($structurefile);

            self::$tablestructure = unserialize($data);

        }

        if (!is_array(self::$tablestructure)) {

            testing_error(

                1,

                "Can not read dataroot/{$framework}/tablestructure.ser or invalid format, reinitialize test database.",

            );

        }

        return self::$tablestructure;

    }

    /**

     * Returns the names of sequences for each autoincrementing id field in all standard tables.

     * @static

     * @return array $table=>$sequencename

     */

    public static function get_sequencenames() {

        global $DB;

        if (isset(self::$sequencenames)) {

            return self::$sequencenames;

        }

        if (!$structure = self::get_tablestructure()) {

            return [];

        }

        self::$sequencenames = [];

        foreach ($structure as $table => $ignored) {

            $name = $DB->get_manager()->generator->getSequenceFromDB(new xmldb_table($table));

            if ($name !== false) {

                self::$sequencenames[$table] = $name;

            }

        }

        return self::$sequencenames;

    }

    /**

     * Returns list of tables that are unmodified and empty.

     *

     * @static

     * @return array of table names, empty if unknown

     */

    protected static function guess_unmodified_empty_tables() {

        global $DB;

        $dbfamily = $DB->get_dbfamily();

        if ($dbfamily === 'mysql') {

            $empties = [];

            $prefix = $DB->get_prefix();

            $rs = $DB->get_recordset_sql("SHOW TABLE STATUS LIKE ?", [$prefix . '%']);

            foreach ($rs as $info) {

                $table = strtolower($info->name);

                if (strpos($table, $prefix) !== 0) {

                    // Incorrect table match caused by _.

                    continue;

                }

                if (!is_null($info->auto_increment) && $info->rows == 0 && ($info->auto_increment == 1)) {

                    $table = preg_replace('/^' . preg_quote($prefix, '/') . '/', '', $table);

                    $empties[$table] = $table;

                }

            }

            $rs->close();

            return $empties;

        } else if ($dbfamily === 'mssql') {

            $empties = [];

            $prefix = $DB->get_prefix();

            $sql = "SELECT t.name

                      FROM sys.identity_columns i

                      JOIN sys.tables t ON t.object_id = i.object_id

                     WHERE t.name LIKE ?

                       AND i.name = 'id'

                       AND i.last_value IS NULL";

            $rs = $DB->get_recordset_sql($sql, [$prefix . '%']);

            foreach ($rs as $info) {

                $table = strtolower($info->name);

                if (strpos($table, $prefix) !== 0) {

                    // Incorrect table match caused by _.

                    continue;

                }

                $table = preg_replace('/^' . preg_quote($prefix, '/') . '/', '', $table);

                $empties[$table] = $table;

            }

            $rs->close();

            return $empties;

        } else {

            return [];

        }

    }

    /**

     * Determine the next unique starting id sequences.

     *

     * @static

     * @param array $records The records to use to determine the starting value for the table.

     * @param string $table table name.

     * @return int The value the sequence should be set to.

     */

    private static function get_next_sequence_starting_value($records, $table) {

        if (isset(self::$tablesequences[$table])) {

            return self::$tablesequences[$table];

        }

        $id = self::$sequencenextstartingid;

        // If there are records, calculate the minimum id we can use.

        // It must be bigger than the last record's id.

        if (!empty($records)) {

            $lastrecord = end($records);

            $id = max($id, $lastrecord->id + 1);

        }

        self::$sequencenextstartingid = $id + 1000;

        self::$tablesequences[$table] = $id;

        return $id;

    }

    /**

     * Reset all database sequences to initial values.

     *

     * @static

     * @param array $empties tables that are known to be unmodified and empty

     * @return void

     */

    public static function reset_all_database_sequences(?array $empties = null) {

        global $DB;

        if (!$data = self::get_tabledata()) {

            // Not initialised yet.

            return;

        }

        if (!$structure = self::get_tablestructure()) {

            // Not initialised yet.

            return;

        }

        $updatedtables = self::$tableupdated;

        // If all starting Id's are the same, it's difficult to detect coding and testing

        // errors that use the incorrect id in tests.  The classic case is cmid vs instance id.

        // To reduce the chance of the coding error, we start sequences at different values where possible.

        // In a attempt to avoid tables with existing id's we start at a high number.

        // Reset the value each time all database sequences are reset.

        if (defined('PHPUNIT_SEQUENCE_START') && PHPUNIT_SEQUENCE_START) {

            self::$sequencenextstartingid = PHPUNIT_SEQUENCE_START;

        } else {

            self::$sequencenextstartingid = 100000;

        }

        $dbfamily = $DB->get_dbfamily();

        if ($dbfamily === 'postgres') {

            $queries = [];

            $prefix = $DB->get_prefix();

            foreach ($data as $table => $records) {

                // If table is not modified then no need to do anything.

                if (!isset($updatedtables[$table])) {

                    continue;

                }

                if (isset($structure[$table]['id']) && $structure[$table]['id']->auto_increment) {

                    $nextid = self::get_next_sequence_starting_value($records, $table);

                    $queries[] = "ALTER SEQUENCE {$prefix}{$table}_id_seq RESTART WITH $nextid";

                }

            }

            if ($queries) {

                $DB->change_database_structure(implode(';', $queries));

            }

        } else if ($dbfamily === 'mysql') {

            $queries = [];

            $sequences = [];

            $prefix = $DB->get_prefix();

            $rs = $DB->get_recordset_sql("SHOW TABLE STATUS LIKE ?", [$prefix . '%']);

            foreach ($rs as $info) {

                $table = strtolower($info->name);

                if (strpos($table, $prefix) !== 0) {

                    // Incorrect table match caused by _.

                    continue;

                }

                if (!is_null($info->auto_increment)) {

                    $table = preg_replace('/^' . preg_quote($prefix, '/') . '/', '', $table);

                    $sequences[$table] = $info->auto_increment;

                }

            }

            $rs->close();

            $prefix = $DB->get_prefix();

            foreach ($data as $table => $records) {

                // If table is not modified then no need to do anything.

                if (!isset($updatedtables[$table])) {

                    continue;

                }

                if (isset($structure[$table]['id']) && $structure[$table]['id']->auto_increment) {

                    if (isset($sequences[$table])) {

                        $nextid = self::get_next_sequence_starting_value($records, $table);

                        if ($sequences[$table] != $nextid) {

                            $queries[] = "ALTER TABLE {$prefix}{$table} AUTO_INCREMENT = $nextid";

                        }

                    } else {

                        // Some problem exists, fallback to standard code.

                        $DB->get_manager()->reset_sequence($table);

                    }

                }

            }

            if ($queries) {

                $DB->change_database_structure(implode(';', $queries));

            }

        } else {

            // Note: does mssql support any kind of faster reset?

            // This also implies mssql will not use unique sequence values.

            if (is_null($empties) && (empty($updatedtables))) {

                $empties = self::guess_unmodified_empty_tables();

            }

            foreach ($data as $table => $records) {

                // If table is not modified then no need to do anything.

                if (isset($empties[$table]) || (!isset($updatedtables[$table]))) {

                    continue;

                }

                if (isset($structure[$table]['id']) && $structure[$table]['id']->auto_increment) {

                    $DB->get_manager()->reset_sequence($table);

                }

            }

        }

    }

    /**

     * Reset all database tables to default values.

     * @static

     * @return bool true if reset done, false if skipped

     */

    public static function reset_database() {

        global $DB;

        $tables = $DB->get_tables(false);

        if (!$tables || empty($tables['config'])) {

            // Not installed yet.

            return false;

        }

        if (!$data = self::get_tabledata()) {

            // Not initialised yet.

            return false;

        }

        if (!$structure = self::get_tablestructure()) {

            // Not initialised yet.

            return false;

        }

        $empties = [];

        // Use local copy of self::$tableupdated, as list gets updated in for loop.

        $updatedtables = self::$tableupdated;

        // If empty tablesequences list then it's the very first run.

        if (empty(self::$tablesequences) && (($DB->get_dbfamily() != 'mysql') && ($DB->get_dbfamily() != 'postgres'))) {

            // Only Mysql and Postgres support random sequence, so don't guess, just reset everything on very first run.

            $empties = self::guess_unmodified_empty_tables();

        }

        // Check if any table has been modified by behat selenium process.

        if (defined('BEHAT_SITE_RUNNING')) {

            // Crazy way to reset :(.

            $tablesupdatedfile = self::get_tables_updated_by_scenario_list_path();

            if ($tablesupdated = @json_decode(file_get_contents($tablesupdatedfile), true)) {

                self::$tableupdated = array_merge(self::$tableupdated, $tablesupdated);

                unlink($tablesupdatedfile);

            }

            $updatedtables = self::$tableupdated;

        }

        foreach ($data as $table => $records) {

            // If table is not modified then no need to do anything.

            // $updatedtables tables is set after the first run, so check before checking for specific table update.

            if (!empty($updatedtables) && !isset($updatedtables[$table])) {

                continue;

            }

            if (empty($records)) {

                if (!isset($empties[$table])) {

                    // Table has been modified and is not empty.

                    $DB->delete_records($table, []);

                }

                continue;

            }

            if (isset($structure[$table]['id']) && $structure[$table]['id']->auto_increment) {

                $currentrecords = $DB->get_records($table, [], 'id ASC');

                $changed = false;

                foreach ($records as $id => $record) {

                    if (!isset($currentrecords[$id])) {

                        $changed = true;

                        break;

                    }

                    if ((array)$record != (array)$currentrecords[$id]) {

                        $changed = true;

                        break;

                    }

                    unset($currentrecords[$id]);

                }

                if (!$changed) {

                    if ($currentrecords) {

                        $lastrecord = end($records);

                        $DB->delete_records_select($table, "id > ?", [$lastrecord->id]);

                        continue;

                    } else {

                        continue;

                    }

                }

            }

            $DB->delete_records($table, []);

            foreach ($records as $record) {

                $DB->import_record($table, $record, false, true);

            }

        }

        // Reset all next record ids - aka sequences.

        self::reset_all_database_sequences($empties);

        // Remove extra tables.

        foreach ($tables as $table) {

            if (!isset($data[$table])) {

                $DB->get_manager()->drop_table(new xmldb_table($table));

            }

        }

        self::reset_updated_table_list();

        return true;

    }

    /**

     * Purge dataroot directory

     * @static

     * @return void

     */

    public static function reset_dataroot() {

        global $CFG;

        $childclassname = self::get_framework() . '_util';

        // Do not delete automatically installed files.

        self::skip_original_data_files($childclassname);

        // Clear file status cache, before checking file_exists.

        clearstatcache();

        // Clean up the dataroot folder.

        $handle = opendir(self::get_dataroot());

        while (false !== ($item = readdir($handle))) {

            if (in_array($item, $childclassname::$datarootskiponreset)) {

                continue;

            }

            if (is_dir(self::get_dataroot() . "/$item")) {

                remove_dir(self::get_dataroot() . "/$item", false);

            } else {

                unlink(self::get_dataroot() . "/$item");

            }

        }

        closedir($handle);

        // Clean up the dataroot/filedir folder.

        if (file_exists(self::get_dataroot() . '/filedir')) {

            $handle = opendir(self::get_dataroot() . '/filedir');

            while (false !== ($item = readdir($handle))) {

                if (in_array('filedir' . DIRECTORY_SEPARATOR . $item, $childclassname::$datarootskiponreset)) {

                    continue;

                }

                if (is_dir(self::get_dataroot() . "/filedir/$item")) {

                    remove_dir(self::get_dataroot() . "/filedir/$item", false);

                } else {

                    unlink(self::get_dataroot() . "/filedir/$item");

                }

            }

            closedir($handle);

        }

        make_temp_directory('');

        make_backup_temp_directory('');

        make_cache_directory('');

        make_localcache_directory('');

        // Purge all data from the caches. This is required for consistency between tests.

        // Any file caches that happened to be within the data root will have already been clearer (because we just deleted cache)

        // and now we will purge any other caches as well.  This must be done before the cache_factory::reset() as that

        // removes all definitions of caches and purge does not have valid caches to operate on.

        cache_helper::purge_all();

        // Reset the cache API so that it recreates it's required directories as well.

        cache_factory::reset();

    }

    /**

     * Gets a text-based site version description.

     *

     * @return string The site info

     */

    public static function get_site_info() {

        global $CFG;

        $output = '';

        // All developers have to understand English, do not localise!

        $env = self::get_environment();

        $output .= "Moodle " . $env['moodleversion'];

        if ($hash = self::get_git_hash()) {

            $output .= ", $hash";

        }

        $output .= "\n";

        // Add php version.

        require_once($CFG->libdir . '/environmentlib.php');

        $output .= "Php: " . normalize_version($env['phpversion']);

        // Add database type and version.

        $output .= ", " . $env['dbtype'] . ": " . $env['dbversion'];

        // OS details.

        $output .= ", OS: " . $env['os'] . "\n";

        return $output;

    }

    /**

     * Try to get current git hash of the Moodle in $CFG->dirroot.

     * @return string null if unknown, sha1 hash if known

     */

    public static function get_git_hash() {

        global $CFG;

        // This is a bit naive, but it should mostly work for all platforms.

        if (!file_exists("$CFG->dirroot/.git/HEAD")) {

            return null;

        }

        $headcontent = file_get_contents("$CFG->dirroot/.git/HEAD");

        if ($headcontent === false) {

            return null;

        }

        $headcontent = trim($headcontent);

        // If it is pointing to a hash we return it directly.

        if (strlen($headcontent) === 40) {

            return $headcontent;

        }

        if (strpos($headcontent, 'ref: ') !== 0) {

            return null;

        }

        $ref = substr($headcontent, 5);

        if (!file_exists("$CFG->dirroot/.git/$ref")) {

            return null;

        }

        $hash = file_get_contents("$CFG->dirroot/.git/$ref");

        if ($hash === false) {

            return null;

        }

        $hash = trim($hash);

        if (strlen($hash) != 40) {

            return null;

        }

        return $hash;

    }

    /**

     * Set state of modified tables.

     *

     * @param string $sql sql which is updating the table.

     */

    public static function set_table_modified_by_sql($sql) {

        global $DB;

        $prefix = $DB->get_prefix();

        preg_match('/( ' . $prefix . '\w*)(.*)/', $sql, $matches);

        // Ignore random sql for testing like "XXUPDATE SET XSSD".

        if (!empty($matches[1])) {

            $table = trim($matches[1]);

            $table = preg_replace('/^' . preg_quote($prefix, '/') . '/', '', $table);

            self::$tableupdated[$table] = true;

            if (defined('BEHAT_SITE_RUNNING')) {

                $tablesupdatedfile = self::get_tables_updated_by_scenario_list_path();

                $tablesupdated = @json_decode(file_get_contents($tablesupdatedfile), true);

                if (!isset($tablesupdated[$table])) {

                    $tablesupdated[$table] = true;

                    @file_put_contents($tablesupdatedfile, json_encode($tablesupdated, JSON_PRETTY_PRINT));

                }

            }

        }

    }

    /**

     * Reset updated table list. This should be done after every reset.

     */

    public static function reset_updated_table_list() {

        self::$tableupdated = [];

    }

    /**

     * Delete tablesupdatedbyscenario file. This should be called before suite,

     * to ensure full db reset.

     */

    public static function clean_tables_updated_by_scenario_list() {

        $tablesupdatedfile = self::get_tables_updated_by_scenario_list_path();

        if (file_exists($tablesupdatedfile)) {

            unlink($tablesupdatedfile);

        }

        // Reset static cache of cli process.

        self::reset_updated_table_list();

    }

    /**

     * Returns the path to the file which holds list of tables updated in scenario.

     * @return string

     */

    final protected static function get_tables_updated_by_scenario_list_path() {

        return self::get_dataroot() . '/tablesupdatedbyscenario.json';

    }

    /**

     * Drop the whole test database

     * @static

     * @param bool $displayprogress

     */

    protected static function drop_database($displayprogress = false) {

        global $DB;

        $tables = $DB->get_tables(false);

        if (isset($tables['config'])) {

            // Config always last to prevent problems with interrupted drops!

            unset($tables['config']);

            $tables['config'] = 'config';

        }

        if ($displayprogress) {

            echo "Dropping tables:\n";

        }

        $dotsonline = 0;

        foreach ($tables as $tablename) {

            $table = new xmldb_table($tablename);

            $DB->get_manager()->drop_table($table);

            if ($dotsonline == 60) {

                if ($displayprogress) {

                    echo "\n";

                }

                $dotsonline = 0;

            }

            if ($displayprogress) {

                echo '.';

            }

            $dotsonline += 1;

        }

        if ($displayprogress) {

            echo "\n";

        }

    }

    /**

     * Drops the test framework dataroot

     * @static

     */

    protected static function drop_dataroot() {

        global $CFG;

        $framework = self::get_framework();

        $childclassname = $framework . '_util';

        $files = scandir(self::get_dataroot() . '/'  . $framework);

        foreach ($files as $file) {

            if (in_array($file, $childclassname::$datarootskipondrop)) {

                continue;

            }

            $path = self::get_dataroot() . '/' . $framework . '/' . $file;

            if (is_dir($path)) {

                remove_dir($path, false);

            } else {

                unlink($path);

            }

        }

        $jsonfilepath = self::get_dataroot() . '/' . self::$originaldatafilesjson;

        if (file_exists($jsonfilepath)) {

            // Delete the json file.

            unlink($jsonfilepath);

            // Delete the dataroot filedir.

            remove_dir(self::get_dataroot() . '/filedir', false);

        }

    }

    /**

     * Skip the original dataroot files to not been reset.

     *

     * @static

     * @param string $utilclassname the util class name..

     */

    protected static function skip_original_data_files($utilclassname) {

        $jsonfilepath = self::get_dataroot() . '/' . self::$originaldatafilesjson;

        if (file_exists($jsonfilepath)) {

            $listfiles = file_get_contents($jsonfilepath);

            // Mark each files as to not be reset.

            if (!empty($listfiles) && !self::$originaldatafilesjsonadded) {

                $originaldatarootfiles = json_decode($listfiles);

                // Keep the json file. Only drop_dataroot() should delete it.

                $originaldatarootfiles[] = self::$originaldatafilesjson;

                $utilclassname::$datarootskiponreset = array_merge(

                    $utilclassname::$datarootskiponreset,

                    $originaldatarootfiles

                );

                self::$originaldatafilesjsonadded = true;

            }

        }

    }

    /**

     * Save the list of the original dataroot files into a json file.

     */

    protected static function save_original_data_files() {

        global $CFG;

        $jsonfilepath = self::get_dataroot() . '/' . self::$originaldatafilesjson;

        // Save the original dataroot files if not done (only executed the first time).

        if (!file_exists($jsonfilepath)) {

            $listfiles = [];

            $currentdir = 'filedir' . DIRECTORY_SEPARATOR . '.';

            $parentdir = 'filedir' . DIRECTORY_SEPARATOR . '..';

            $listfiles[$currentdir] = $currentdir;

            $listfiles[$parentdir] = $parentdir;

            $filedir = self::get_dataroot() . '/filedir';

            if (file_exists($filedir)) {

                $directory = new RecursiveDirectoryIterator($filedir);

                foreach (new RecursiveIteratorIterator($directory) as $file) {

                    if ($file->isDir()) {

                        $key = substr($file->getPath(), strlen(self::get_dataroot() . '/'));

                    } else {

                        $key = substr($file->getPathName(), strlen(self::get_dataroot() . '/'));

                    }

                    $listfiles[$key] = $key;

                }

            }

            // Save the file list in a JSON file.

            $fp = fopen($jsonfilepath, 'w');

            fwrite($fp, json_encode(array_values($listfiles)));

            fclose($fp);

        }

    }

    /**

     * Return list of environment versions on which tests will run.

     * Environment includes:

     * - moodleversion

     * - phpversion

     * - dbtype

     * - dbversion

     * - os

     *

     * @return array

     */

    public static function get_environment() {

        global $CFG, $DB;

        $env = [];

        // Add moodle version.

        $release = null;

        require("$CFG->dirroot/version.php");

        $env['moodleversion'] = $release;

        // Add php version.

        $phpversion = phpversion();

        $env['phpversion'] = $phpversion;

        // Add database type and version.

        $dbtype = $CFG->dbtype;

        $dbinfo = $DB->get_server_info();

        $dbversion = $dbinfo['version'];

        $env['dbtype'] = $dbtype;

        $env['dbversion'] = $dbversion;

        // OS details.

        $osdetails = php_uname('s') . " " . php_uname('r') . " " . php_uname('m');

        $env['os'] = $osdetails;