TestBase.php

<?php

/**
 * @file
 * Definition of \Drupal\simpletest\TestBase.
 */

namespace Drupal\simpletest;

use Drupal\Component\Utility\Random;
use Drupal\Core\Database\Database;
use Drupal\Component\Utility\Settings;
use Drupal\Component\Utility\String;
use Drupal\Core\Config\ConfigImporter;
use Drupal\Core\Config\StorageComparer;
use Drupal\Core\DependencyInjection\ContainerBuilder;
use Drupal\Core\Database\ConnectionNotDefinedException;
use Drupal\Core\Config\StorageInterface;
use Drupal\Core\DrupalKernel;
use Drupal\Core\Language\Language;
use Drupal\Core\StreamWrapper\PublicStream;
use Drupal\Core\Utility\Error;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\DependencyInjection\Reference;

/**
 * Base class for Drupal tests.
 *
 * Do not extend this class directly; use either
 * \Drupal\simpletest\WebTestBase or \Drupal\simpletest\UnitTestBase.
 */
abstract class TestBase {
  /**
   * The test run ID.
   *
   * @var string
   */
  protected $testId;

  /**
   * The site directory of this test run.
   *
   * @var string
   */
  protected $siteDirectory = NULL;

  /**
   * The database prefix of this test run.
   *
   * @var string
   */
  protected $databasePrefix = NULL;

  /**
   * The original file directory, before it was changed for testing purposes.
   *
   * @var string
   */
  protected $originalFileDirectory = NULL;

  /**
   * Time limit for the test.
   */
  protected $timeLimit = 500;

  /**
   * Current results of this test case.
   *
   * @var Array
   */
  public $results = array(
    '#pass' => 0,
    '#fail' => 0,
    '#exception' => 0,
    '#debug' => 0,
  );

  /**
   * Assertions thrown in that test case.
   *
   * @var Array
   */
  protected $assertions = array();

  /**
   * This class is skipped when looking for the source of an assertion.
   *
   * When displaying which function an assert comes from, it's not too useful
   * to see "WebTestBase->drupalLogin()', we would like to see the test
   * that called it. So we need to skip the classes defining these helper
   * methods.
   */
  protected $skipClasses = array(__CLASS__ => TRUE);

  /**
   * TRUE if verbose debugging is enabled.
   *
   * @var boolean
   */
  public $verbose;

  /**
   * Incrementing identifier for verbose output filenames.
   *
   * @var integer
   */
  protected $verboseId = 0;

  /**
   * Safe class name for use in verbose output filenames.
   *
   * Namespaces separator (\) replaced with _.
   *
   * @var string
   */
  protected $verboseClassName;

  /**
   * Directory where verbose output files are put.
   *
   * @var string
   */
  protected $verboseDirectory;

  /**
   * The original database prefix when running inside Simpletest.
   *
   * @var string
   */
  protected $originalPrefix;

  /**
   * URL to the verbose output file directory.
   *
   * @var string
   */
  protected $verboseDirectoryUrl;

  /**
   * The settings array.
   */
  protected $originalSettings;

  /**
   * The public file directory for the test environment.
   *
   * This is set in TestBase::prepareEnvironment().
   *
   * @var string
   */
  protected $public_files_directory;

  /**
   * Whether to die in case any test assertion fails.
   *
   * @var boolean
   *
   * @see run-tests.sh
   */
  public $dieOnFail = FALSE;

  /**
   * The DrupalKernel instance used in the test.
   *
   * @var \Drupal\Core\DrupalKernel
   */
  protected $kernel;

  /**
   * The dependency injection container used in the test.
   *
   * @var \Symfony\Component\DependencyInjection\ContainerInterface
   */
  protected $container;

  /**
   * The config importer that can used in a test.
   *
   * @var \Drupal\Core\Config\ConfigImporter
   */
  protected $configImporter;

  /**
   * The random generator.
   *
   * @var \Drupal\Component\Utility\Random
   */
  protected $randomGenerator;

  /**
   * Constructor for Test.
   *
   * @param $test_id
   *   Tests with the same id are reported together.
   */
  public function __construct($test_id = NULL) {
    $this->testId = $test_id;
  }

  /**
   * Provides meta information about this test case, such as test name.
   *
   * @return array
   *   An array of untranslated strings with the following keys:
   *   - name: An overview of what is tested by the class; for example, "User
   *     access rules".
   *   - description: One sentence describing the test, starting with a verb.
   *   - group: The human-readable name of the module ("Node", "Statistics"), or
   *     the human-readable name of the Drupal facility tested (e.g. "Form API"
   *     or "XML-RPC").
   */
  public static function getInfo() {
    // PHP does not allow us to declare this method as abstract public static,
    // so we simply throw an exception here if this has not been implemented by
    // a child class.
    throw new \RuntimeException(String::format('@class must implement \Drupal\simpletest\TestBase::getInfo().', array(
      '@class' => get_called_class(),
    )));
  }

  /**
   * Performs setup tasks before each individual test method is run.
   */
  abstract protected function setUp();

  /**
   * Checks the matching requirements for Test.
   *
   * @return
   *   Array of errors containing a list of unmet requirements.
   */
  protected function checkRequirements() {
    return array();
  }

  /**
   * Internal helper: stores the assert.
   *
   * @param $status
   *   Can be 'pass', 'fail', 'exception', 'debug'.
   *   TRUE is a synonym for 'pass', FALSE for 'fail'.
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   * @param $caller
   *   By default, the assert comes from a function whose name starts with
   *   'test'. Instead, you can specify where this assert originates from
   *   by passing in an associative array as $caller. Key 'file' is
   *   the name of the source file, 'line' is the line number and 'function'
   *   is the caller function itself.
   */
  protected function assert($status, $message = '', $group = 'Other', array $caller = NULL) {
    // Convert boolean status to string status.
    if (is_bool($status)) {
      $status = $status ? 'pass' : 'fail';
    }

    // Increment summary result counter.
    $this->results['#' . $status]++;

    // Get the function information about the call to the assertion method.
    if (!$caller) {
      $caller = $this->getAssertionCall();
    }

    // Creation assertion array that can be displayed while tests are running.
    $this->assertions[] = $assertion = array(
      'test_id' => $this->testId,
      'test_class' => get_class($this),
      'status' => $status,
      'message' => $message,
      'message_group' => $group,
      'function' => $caller['function'],
      'line' => $caller['line'],
      'file' => $caller['file'],
    );

    // Store assertion for display after the test has completed.
    self::getDatabaseConnection()
      ->insert('simpletest')
      ->fields($assertion)
      ->execute();

    // We do not use a ternary operator here to allow a breakpoint on
    // test failure.
    if ($status == 'pass') {
      return TRUE;
    }
    else {
      if ($this->dieOnFail && ($status == 'fail' || $status == 'exception')) {
        exit(1);
      }
      return FALSE;
    }
  }

  /**
   * Store an assertion from outside the testing context.
   *
   * This is useful for inserting assertions that can only be recorded after
   * the test case has been destroyed, such as PHP fatal errors. The caller
   * information is not automatically gathered since the caller is most likely
   * inserting the assertion on behalf of other code. In all other respects
   * the method behaves just like \Drupal\simpletest\TestBase::assert() in terms
   * of storing the assertion.
   *
   * @return
   *   Message ID of the stored assertion.
   *
   * @see \Drupal\simpletest\TestBase::assert()
   * @see \Drupal\simpletest\TestBase::deleteAssert()
   */
  public static function insertAssert($test_id, $test_class, $status, $message = '', $group = 'Other', array $caller = array()) {
    // Convert boolean status to string status.
    if (is_bool($status)) {
      $status = $status ? 'pass' : 'fail';
    }

    $caller += array(
      'function' => 'Unknown',
      'line' => 0,
      'file' => 'Unknown',
    );

    $assertion = array(
      'test_id' => $test_id,
      'test_class' => $test_class,
      'status' => $status,
      'message' => $message,
      'message_group' => $group,
      'function' => $caller['function'],
      'line' => $caller['line'],
      'file' => $caller['file'],
    );

    return self::getDatabaseConnection()
      ->insert('simpletest')
      ->fields($assertion)
      ->execute();
  }

  /**
   * Delete an assertion record by message ID.
   *
   * @param $message_id
   *   Message ID of the assertion to delete.
   *
   * @return
   *   TRUE if the assertion was deleted, FALSE otherwise.
   *
   * @see \Drupal\simpletest\TestBase::insertAssert()
   */
  public static function deleteAssert($message_id) {
    return (bool) self::getDatabaseConnection()
      ->delete('simpletest')
      ->condition('message_id', $message_id)
      ->execute();
  }

  /**
   * Returns the database connection to the site running Simpletest.
   *
   * @return \Drupal\Core\Database\Connection
   *   The database connection to use for inserting assertions.
   */
  public static function getDatabaseConnection() {
    try {
      $connection = Database::getConnection('default', 'simpletest_original_default');
    }
    catch (ConnectionNotDefinedException $e) {
      // If the test was not set up, the simpletest_original_default
      // connection does not exist.
      $connection = Database::getConnection('default', 'default');
    }
    return $connection;
  }

  /**
   * Cycles through backtrace until the first non-assertion method is found.
   *
   * @return
   *   Array representing the true caller.
   */
  protected function getAssertionCall() {
    $backtrace = debug_backtrace();

    // The first element is the call. The second element is the caller.
    // We skip calls that occurred in one of the methods of our base classes
    // or in an assertion function.
   while (($caller = $backtrace[1]) &&
         ((isset($caller['class']) && isset($this->skipClasses[$caller['class']])) ||
           substr($caller['function'], 0, 6) == 'assert')) {
      // We remove that call.
      array_shift($backtrace);
    }

    return Error::getLastCaller($backtrace);
  }

  /**
   * Check to see if a value is not false.
   *
   * False values are: empty string, 0, NULL, and FALSE.
   *
   * @param $value
   *   The value on which the assertion is to be done.
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   *
   * @return
   *   TRUE if the assertion succeeded, FALSE otherwise.
   */
  protected function assertTrue($value, $message = '', $group = 'Other') {
    return $this->assert((bool) $value, $message ? $message : String::format('Value @value is TRUE.', array('@value' => var_export($value, TRUE))), $group);
  }

  /**
   * Check to see if a value is false.
   *
   * False values are: empty string, 0, NULL, and FALSE.
   *
   * @param $value
   *   The value on which the assertion is to be done.
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   *
   * @return
   *   TRUE if the assertion succeeded, FALSE otherwise.
   */
  protected function assertFalse($value, $message = '', $group = 'Other') {
    return $this->assert(!$value, $message ? $message : String::format('Value @value is FALSE.', array('@value' => var_export($value, TRUE))), $group);
  }

  /**
   * Check to see if a value is NULL.
   *
   * @param $value
   *   The value on which the assertion is to be done.
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   *
   * @return
   *   TRUE if the assertion succeeded, FALSE otherwise.
   */
  protected function assertNull($value, $message = '', $group = 'Other') {
    return $this->assert(!isset($value), $message ? $message : String::format('Value @value is NULL.', array('@value' => var_export($value, TRUE))), $group);
  }

  /**
   * Check to see if a value is not NULL.
   *
   * @param $value
   *   The value on which the assertion is to be done.
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   *
   * @return
   *   TRUE if the assertion succeeded, FALSE otherwise.
   */
  protected function assertNotNull($value, $message = '', $group = 'Other') {
    return $this->assert(isset($value), $message ? $message : String::format('Value @value is not NULL.', array('@value' => var_export($value, TRUE))), $group);
  }

  /**
   * Check to see if two values are equal.
   *
   * @param $first
   *   The first value to check.
   * @param $second
   *   The second value to check.
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   *
   * @return
   *   TRUE if the assertion succeeded, FALSE otherwise.
   */
  protected function assertEqual($first, $second, $message = '', $group = 'Other') {
    return $this->assert($first == $second, $message ? $message : String::format('Value @first is equal to value @second.', array('@first' => var_export($first, TRUE), '@second' => var_export($second, TRUE))), $group);
  }

  /**
   * Check to see if two values are not equal.
   *
   * @param $first
   *   The first value to check.
   * @param $second
   *   The second value to check.
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   *
   * @return
   *   TRUE if the assertion succeeded, FALSE otherwise.
   */
  protected function assertNotEqual($first, $second, $message = '', $group = 'Other') {
    return $this->assert($first != $second, $message ? $message : String::format('Value @first is not equal to value @second.', array('@first' => var_export($first, TRUE), '@second' => var_export($second, TRUE))), $group);
  }

  /**
   * Check to see if two values are identical.
   *
   * @param $first
   *   The first value to check.
   * @param $second
   *   The second value to check.
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   *
   * @return
   *   TRUE if the assertion succeeded, FALSE otherwise.
   */
  protected function assertIdentical($first, $second, $message = '', $group = 'Other') {
    return $this->assert($first === $second, $message ? $message : String::format('Value @first is identical to value @second.', array('@first' => var_export($first, TRUE), '@second' => var_export($second, TRUE))), $group);
  }

  /**
   * Check to see if two values are not identical.
   *
   * @param $first
   *   The first value to check.
   * @param $second
   *   The second value to check.
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   *
   * @return
   *   TRUE if the assertion succeeded, FALSE otherwise.
   */
  protected function assertNotIdentical($first, $second, $message = '', $group = 'Other') {
    return $this->assert($first !== $second, $message ? $message : String::format('Value @first is not identical to value @second.', array('@first' => var_export($first, TRUE), '@second' => var_export($second, TRUE))), $group);
  }

  /**
   * Checks to see if two objects are identical.
   *
   * @param object $object1
   *   The first object to check.
   * @param object $object2
   *   The second object to check.
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   *
   * @return
   *   TRUE if the assertion succeeded, FALSE otherwise.
   */
  protected function assertIdenticalObject($object1, $object2, $message = '', $group = 'Other') {
    $message = $message ?: String::format('!object1 is identical to !object2', array(
      '!object1' => var_export($object1, TRUE),
      '!object2' => var_export($object2, TRUE),
    ));
    $identical = TRUE;
    foreach ($object1 as $key => $value) {
      $identical = $identical && isset($object2->$key) && $object2->$key === $value;
    }
    return $this->assertTrue($identical, $message, $group);
  }

  /**
   * Asserts that no errors have been logged to the PHP error.log thus far.
   *
   * @return bool
   *   TRUE if the assertion succeeded, FALSE otherwise.
   *
   * @see TestBase::prepareEnvironment()
   * @see _drupal_bootstrap_configuration()
   */
  protected function assertNoErrorsLogged() {
    // Since PHP only creates the error.log file when an actual error is
    // triggered, it is sufficient to check whether the file exists.
    return $this->assertFalse(file_exists(DRUPAL_ROOT . '/' . $this->siteDirectory . '/error.log'), 'PHP error.log is empty.');
  }

  /**
   * Fire an assertion that is always positive.
   *
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   *
   * @return
   *   TRUE.
   */
  protected function pass($message = NULL, $group = 'Other') {
    return $this->assert(TRUE, $message, $group);
  }

  /**
   * Fire an assertion that is always negative.
   *
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   *
   * @return
   *   FALSE.
   */
  protected function fail($message = NULL, $group = 'Other') {
    return $this->assert(FALSE, $message, $group);
  }

  /**
   * Fire an error assertion.
   *
   * @param $message
   *   (optional) A message to display with the assertion. Do not translate
   *   messages: use \Drupal\Component\Utility\String::format() to embed
   *   variables in the message text, not t(). If left blank, a default message
   *   will be displayed.
   * @param $group
   *   (optional) The group this message is in, which is displayed in a column
   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
   *   translate this string. Defaults to 'Other'; most tests do not override
   *   this default.
   * @param $caller
   *   The caller of the error.
   *
   * @return
   *   FALSE.
   */
  protected function error($message = '', $group = 'Other', array $caller = NULL) {
    if ($group == 'User notice') {
      // Since 'User notice' is set by trigger_error() which is used for debug
      // set the message to a status of 'debug'.
      return $this->assert('debug', $message, 'Debug', $caller);
    }

    return $this->assert('exception', $message, $group, $caller);
  }

  /**
   * Logs verbose message in a text file.
   *
   * The a link to the vebose message will be placed in the test results via
   * as a passing assertion with the text '[verbose message]'.
   *
   * @param $message
   *   The verbose message to be stored.
   *
   * @see simpletest_verbose()
   */
  protected function verbose($message) {
    // Do nothing if verbose debugging is disabled.
    if (!$this->verbose) {
      return;
    }

    $message = '<hr />ID #' . $this->verboseId . ' (<a href="' . $this->verboseClassName . '-' . ($this->verboseId - 1) . '.html">Previous</a> | <a href="' . $this->verboseClassName . '-' . ($this->verboseId + 1) . '.html">Next</a>)<hr />' . $message;
    $verbose_filename = $this->verboseDirectory . '/' . $this->verboseClassName . '-' . $this->verboseId . '.html';
    if (file_put_contents($verbose_filename, $message, FILE_APPEND)) {
      $url = $this->verboseDirectoryUrl . '/' . $this->verboseClassName . '-' . $this->verboseId . '.html';
      // Not using l() to avoid invoking the theme system, so that unit tests
      // can use verbose() as well.
      $url = '<a href="' . $url . '" target="_blank">Verbose message</a>';
      $this->error($url, 'User notice');
    }
    $this->verboseId++;
  }

  /**
   * Run all tests in this class.
   *
   * Regardless of whether $methods are passed or not, only method names
   * starting with "test" are executed.
   *
   * @param $methods
   *   (optional) A list of method names in the test case class to run; e.g.,
   *   array('testFoo', 'testBar'). By default, all methods of the class are
   *   taken into account, but it can be useful to only run a few selected test
   *   methods during debugging.
   */
  public function run(array $methods = array()) {
    TestServiceProvider::$currentTest = $this;
    $simpletest_config = \Drupal::config('simpletest.settings');

    $class = get_class($this);
    // Unless preset from run-tests.sh, retrieve the current verbose setting.
    if (!isset($this->verbose)) {
      $this->verbose = $simpletest_config->get('verbose');
    }
    if ($this->verbose) {
      // Initialize verbose debugging.
      $this->verbose = TRUE;
      $this->verboseDirectory = PublicStream::basePath() . '/simpletest/verbose';
      $this->verboseDirectoryUrl = file_create_url($this->verboseDirectory);
      if (file_prepare_directory($this->verboseDirectory, FILE_CREATE_DIRECTORY) && !file_exists($this->verboseDirectory . '/.htaccess')) {
        file_put_contents($this->verboseDirectory . '/.htaccess', "<IfModule mod_expires.c>\nExpiresActive Off\n</IfModule>\n");
      }
      $this->verboseClassName = str_replace("\\", "_", $class);
    }
    // HTTP auth settings (<username>:<password>) for the simpletest browser
    // when sending requests to the test site.
    $this->httpauth_method = (int) $simpletest_config->get('httpauth.method');
    $username = $simpletest_config->get('httpauth.username');
    $password = $simpletest_config->get('httpauth.password');
    if (!empty($username) && !empty($password)) {
      $this->httpauth_credentials = $username . ':' . $password;
    }

    set_error_handler(array($this, 'errorHandler'));
    // Iterate through all the methods in this class, unless a specific list of
    // methods to run was passed.
    $class_methods = get_class_methods($class);
    if ($methods) {
      $class_methods = array_intersect($class_methods, $methods);
    }
    $missing_requirements = $this->checkRequirements();
    if (!empty($missing_requirements)) {
      $missing_requirements_object = new \ReflectionObject($this);
      $caller = array(
        'file' => $missing_requirements_object->getFileName(),
      );
      foreach ($missing_requirements as $missing_requirement) {
        TestBase::insertAssert($this->testId, $class, FALSE, $missing_requirement, 'Requirements check.', $caller);
      }
    }
    else {
      if (defined("$class::SORT_METHODS")) {
        sort($class_methods);
      }
      foreach ($class_methods as $method) {
        // If the current method starts with "test", run it - it's a test.
        if (strtolower(substr($method, 0, 4)) == 'test') {
          // Insert a fail record. This will be deleted on completion to ensure
          // that testing completed.
          $method_info = new \ReflectionMethod($class, $method);
          $caller = array(
            'file' => $method_info->getFileName(),
            'line' => $method_info->getStartLine(),
            'function' => $class . '->' . $method . '()',
          );
          $completion_check_id = TestBase::insertAssert($this->testId, $class, FALSE, 'The test did not complete due to a fatal error.', 'Completion check', $caller);
          try {
            $this->prepareEnvironment();
          }
          catch (\Exception $e) {
            $this->exceptionHandler($e);
            // The prepareEnvironment() method isolates the test from the parent
            // Drupal site by creating a random database prefix and test site
            // directory. If this fails, a test would possibly operate in the
            // parent site. Therefore, the entire test run for this test class
            // has to be aborted.
            // restoreEnvironment() cannot be called, because we do not know
            // where exactly the environment setup failed.
            break;
          }
          try {
            $this->setUp();
          }
          catch (\Exception $e) {
            $this->exceptionHandler($e);
            // Abort if setUp() fails, since all test methods will fail.
            // But ensure to clean up and restore the environment, since
            // prepareEnvironment() succeeded.
            $this->restoreEnvironment();
            break;
          }
          try {
            $this->$method();
          }
          catch (\Exception $e) {
            $this->exceptionHandler($e);
          }
          try {
            $this->tearDown();
          }
          catch (\Exception $e) {
            $this->exceptionHandler($e);
            // If a test fails to tear down, abort the entire test class, since
            // it is likely that all tests will fail in the same way and a
            // failure here only results in additional test artifacts that have
            // to be manually deleted.
            $this->restoreEnvironment();
            break;
          }
          $this->restoreEnvironment();
          // Remove the completion check record.
          TestBase::deleteAssert($completion_check_id);
        }
      }
    }
    TestServiceProvider::$currentTest = NULL;
    // Clear out the error messages and restore error handler.
    drupal_get_messages();
    restore_error_handler();
  }

  /**
   * Generates a database prefix for running tests.
   *
   * The database prefix is used by prepareEnvironment() to setup a public files
   * directory for the test to be run, which also contains the PHP error log,
   * which is written to in case of a fatal error. Since that directory is based
   * on the database prefix, all tests (even unit tests) need to have one, in
   * order to access and read the error log.
   *
   * @see TestBase::prepareEnvironment()
   *
   * The generated database table prefix is used for the Drupal installation
   * being performed for the test. It is also used as user agent HTTP header
   * value by the cURL-based browser of DrupalWebTestCase, which is sent to the
   * Drupal installation of the test. During early Drupal bootstrap, the user
   * agent HTTP header is parsed, and if it matches, all database queries use
   * the database table prefix that has been generated here.
   *
   * @see WebTestBase::curlInitialize()
   * @see drupal_valid_test_ua()
   */
  private function prepareDatabasePrefix() {
    // Ensure that the generated test site directory does not exist already,
    // which may happen with a large amount of concurrent threads and
    // long-running tests.
    do {
      $suffix = mt_rand(100000, 999999);
      $this->siteDirectory = 'sites/simpletest/' . $suffix;
      $this->databasePrefix = 'simpletest' . $suffix;
    } while (is_dir(DRUPAL_ROOT . '/' . $this->siteDirectory));

    // As soon as the database prefix is set, the test might start to execute.
    // All assertions as well as the SimpleTest batch operations are associated
    // with the testId, so the database prefix has to be associated with it.
    $affected_rows = db_update('simpletest_test_id')
      ->fields(array('last_prefix' => $this->databasePrefix))
      ->condition('test_id', $this->testId)
      ->execute();
    if (!$affected_rows) {
      throw new \RuntimeException('Failed to set up database prefix.');
    }
  }

  /**
   * Changes the database connection to the prefixed one.
   *
   * @see TestBase::prepareEnvironment()
   */
  private function changeDatabasePrefix() {
    if (empty($this->databasePrefix)) {
      $this->prepareDatabasePrefix();
    }

    // Clone the current connection and replace the current prefix.
    $connection_info = Database::getConnectionInfo('default');
    Database::renameConnection('default', 'simpletest_original_default');
    foreach ($connection_info as $target => $value) {
      $connection_info[$target]['prefix'] = $value['prefix']['default'] . $this->databasePrefix;
    }
    Database::addConnectionInfo('default', 'default', $connection_info['default']);
  }

  /**
   * Act on global state information before the environment is altered for a test.
   *
   * Allows e.g. DrupalUnitTestBase to prime system/extension info from the
   * parent site (and inject it into the test environment so as to improve
   * performance).
   */
  protected function beforePrepareEnvironment() {
  }

  /**
   * Prepares the current environment for running the test.
   *
   * Backups various current environment variables and resets them, so they do
   * not interfere with the Drupal site installation in which tests are executed
   * and can be restored in TestBase::restoreEnvironment().
   *
   * Also sets up new resources for the testing environment, such as the public
   * filesystem and configuration directories.
   *
   * This method is private as it must only be called once by TestBase::run()
   * (multiple invocations for the same test would have unpredictable
   * consequences) and it must not be callable or overridable by test classes.
   *
   * @see TestBase::beforePrepareEnvironment()
   */
  private function prepareEnvironment() {
    global $user;

    // Allow (base) test classes to backup global state information.
    $this->beforePrepareEnvironment();

    // Create the database prefix for this test.
    $this->prepareDatabasePrefix();

    $language_interface = language(Language::TYPE_INTERFACE);

    // When running the test runner within a test, back up the original database
    // prefix.
    if (DRUPAL_TEST_IN_CHILD_SITE) {
      $this->originalPrefix = drupal_valid_test_ua();
    }

    // Backup current in-memory configuration.
    $this->originalSite = conf_path();
    $this->originalSettings = settings()->getAll();
    $this->originalConfig = $GLOBALS['config'];

    // Backup statics and globals.
    $this->originalContainer = clone \Drupal::getContainer();
    $this->originalLanguage = $language_interface;
    $this->originalConfigDirectories = $GLOBALS['config_directories'];
    if (isset($GLOBALS['theme_key'])) {
      $this->originalThemeKey = $GLOBALS['theme_key'];
    }
    $this->originalTheme = isset($GLOBALS['theme']) ? $GLOBALS['theme'] : NULL;

    // Save further contextual information.
    // Use the original files directory to avoid nesting it within an existing
    // simpletest directory if a test is executed within a test.