class InstallerTestBase

abstract class InstallerTestBase extends BrowserTestBase {
    use RequirementsPageTrait;
    
    /**
     * Custom settings.php values to write for a test run.
     *
     * @var array
     *   An array of settings to write out, in the format expected by
     *   SettingsEditor::rewrite().
     *
     * @see \Drupal\Core\Site\SettingsEditor::rewrite()
     */
    protected $settings = [];
    
    /**
     * The language code in which to install Drupal.
     *
     * @var string
     */
    protected $langcode = 'en';
    
    /**
     * The installation profile to install.
     *
     * @var string
     */
    protected $profile = 'testing';
    
    /**
     * Additional parameters to use for installer screens.
     *
     * @see FunctionalTestSetupTrait::installParameters()
     *
     * @var array
     */
    protected $parameters = [];
    
    /**
     * A string translation map used for translated installer screens.
     *
     * Keys are English strings, values are translated strings.
     *
     * @var array
     */
    protected $translations = [
        'Save and continue' => 'Save and continue',
    ];
    
    /**
     * Whether the installer has completed.
     *
     * @var bool
     */
    protected $isInstalled = FALSE;
    
    /**
     * {@inheritdoc}
     */
    protected function installParameters() {
        $params = parent::installParameters();
        // Set the checkbox values to FALSE so that
        // \Drupal\Tests\BrowserTestBase::translatePostValues() does not remove
        // them.
        $params['forms']['install_configure_form']['enable_update_status_module'] = FALSE;
        $params['forms']['install_configure_form']['enable_update_status_emails'] = FALSE;
        return $params;
    }
    
    /**
     * We are testing the installer, so set up a minimal environment for that.
     */
    public function installDrupal() {
        // Define information about the user 1 account.
        $this->rootUser = new UserSession([
            'uid' => 1,
            'name' => 'admin',
            'mail' => 'admin@example.com',
            'pass_raw' => $this->randomMachineName(),
        ]);
        // If any $settings are defined for this test, copy and prepare an actual
        // settings.php, so as to resemble a regular installation.
        if (!empty($this->settings)) {
            // Not using File API; a potential error must trigger a PHP warning.
            copy(DRUPAL_ROOT . '/sites/default/default.settings.php', DRUPAL_ROOT . '/' . $this->siteDirectory . '/settings.php');
            $this->writeSettings($this->settings);
        }
        // Note that FunctionalTestSetupTrait::installParameters() returns form
        // input values suitable for a programmed
        // \Drupal::formBuilder()->submitForm().
        // @see InstallerTestBase::translatePostValues()
        $this->parameters = $this->installParameters();
        // Set up a minimal container (required by BrowserTestBase). Set cookie and
        // server information so that XDebug works.
        // @see install_begin_request()
        $request = Request::create($GLOBALS['base_url'] . '/core/install.php', 'GET', [], $_COOKIE, [], $_SERVER);
        $request->setSession(new Session(new MockArraySessionStorage()));
        $this->container = new ContainerBuilder();
        $request_stack = new RequestStack();
        $request_stack->push($request);
        $this->container
            ->set('request_stack', $request_stack);
        $this->container
            ->setParameter('language.default_values', Language::$defaultValues);
        $this->container
            ->register('language.default', 'Drupal\\Core\\Language\\LanguageDefault')
            ->addArgument('%language.default_values%');
        $this->container
            ->register('string_translation', 'Drupal\\Core\\StringTranslation\\TranslationManager')
            ->addArgument(new Reference('language.default'));
        $this->container
            ->register('http_client', 'GuzzleHttp\\Client')
            ->setFactory('http_client_factory:fromOptions');
        $this->container
            ->register('http_client_factory', 'Drupal\\Core\\Http\\ClientFactory')
            ->setArguments([
            new Reference('http_handler_stack'),
        ]);
        $handler_stack = HandlerStack::create();
        $test_http_client_middleware = new TestHttpClientMiddleware();
        $handler_stack->push($test_http_client_middleware(), 'test.http_client.middleware');
        $this->container
            ->set('http_handler_stack', $handler_stack);
        $this->container
            ->setParameter('app.root', DRUPAL_ROOT);
        \Drupal::setContainer($this->container);
    }
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        $this->visitInstaller();
        // Select language.
        $this->setUpLanguage();
        // Select profile.
        $this->setUpProfile();
        // Address the requirements problem screen, if any.
        $this->setUpRequirementsProblem();
        // Configure settings.
        $this->setUpSettings();
        // @todo Allow test classes based on this class to act on further installer
        //   screens.
        // Configure site.
        $this->setUpSite();
        if ($this->isInstalled) {
            // Import new settings.php written by the installer.
            $request = Request::createFromGlobals();
            $class_loader = (require $this->container
                ->getParameter('app.root') . '/autoload.php');
            Settings::initialize($this->container
                ->getParameter('app.root'), DrupalKernel::findSitePath($request), $class_loader);
            // After writing settings.php, the installer removes write permissions
            // from the site directory. To allow drupal_generate_test_ua() to write
            // a file containing the private key for drupal_valid_test_ua(), the site
            // directory has to be writable.
            // BrowserTestBase::tearDown() will delete the entire test site directory.
            // Not using File API; a potential error must trigger a PHP warning.
            chmod($this->container
                ->getParameter('app.root') . '/' . $this->siteDirectory, 0777);
            $this->kernel = DrupalKernel::createFromRequest($request, $class_loader, 'prod', FALSE);
            $this->kernel
                ->boot();
            $this->kernel
                ->preHandle($request);
            $this->container = $this->kernel
                ->getContainer();
            // Manually configure the test mail collector implementation to prevent
            // tests from sending out emails and collect them in state instead.
            $this->container
                ->get('config.factory')
                ->getEditable('system.mail')
                ->set('interface.default', 'test_mail_collector')
                ->set('mailer_dsn', [
                'scheme' => 'null',
                'host' => 'null',
                'user' => NULL,
                'password' => NULL,
                'port' => NULL,
                'options' => [],
            ])
                ->save();
            $this->installDefaultThemeFromClassProperty($this->container);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    protected function initFrontPage() {
        // We don't want to visit the front page with the installer when
        // initializing Mink, so we do nothing here.
    }
    
    /**
     * Visits the interactive installer.
     */
    protected function visitInstaller() {
        $this->drupalGet($GLOBALS['base_url'] . '/core/install.php');
    }
    
    /**
     * Installer step: Select language.
     *
     * @see \Drupal\Core\Installer\Form\SelectLanguageForm
     */
    protected function setUpLanguage() {
        $edit = [
            'langcode' => $this->langcode,
        ];
        // The 'Select Language' step is always English.
        $this->submitForm($edit, 'Save and continue');
    }
    
    /**
     * Installer step: Select installation profile.
     */
    protected function setUpProfile() {
        $edit = [
            'profile' => $this->profile,
        ];
        $this->submitForm($edit, $this->translations['Save and continue']);
    }
    
    /**
     * Installer step: Configure settings.
     */
    protected function setUpSettings() {
        $parameters = $this->parameters['forms']['install_settings_form'];
        $driver = $parameters['driver'];
        unset($parameters[$driver]['dependencies']);
        $edit = $this->translatePostValues($parameters);
        $this->submitForm($edit, $this->translations['Save and continue']);
    }
    
    /**
     * Installer step: Requirements problem.
     *
     * Override this method to test specific requirements warnings or errors
     * during the installer.
     *
     * @see system_requirements()
     */
    protected function setUpRequirementsProblem() {
        if (version_compare(phpversion(), PhpRequirements::getMinimumSupportedPhp()) < 0) {
            $this->continueOnExpectedWarnings([
                'PHP',
            ]);
        }
    }
    
    /**
     * Final installer step: Configure site.
     */
    protected function setUpSite() {
        $edit = $this->translatePostValues($this->parameters['forms']['install_configure_form']);
        $this->submitForm($edit, $this->translations['Save and continue']);
        // If we've got to this point the site is installed using the regular
        // installation workflow.
        $this->isInstalled = TRUE;
    }
    
    /**
     * {@inheritdoc}
     *
     * FunctionalTestSetupTrait::refreshVariables() tries to operate on persistent
     * storage, which is only available after the installer completed.
     */
    protected function refreshVariables() {
        if ($this->isInstalled) {
            parent::refreshVariables();
        }
    }

}