class ErrorHandlerTest

class ErrorHandlerTest extends BrowserTestBase {
    
    /**
     * Modules to enable.
     *
     * @var array
     */
    protected static $modules = [
        'error_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * Tests the error handler.
     */
    public function testErrorHandler() : void {
        $config = $this->config('system.logging');
        $error_notice = [
            '%type' => 'Notice',
            '@message' => 'Object of class stdClass could not be converted to int',
            '%function' => 'Drupal\\error_test\\Controller\\ErrorTestController->generateWarnings()',
            '%file' => $this->getModulePath('error_test') . '/error_test.module',
        ];
        $error_warning = [
            '%type' => 'Warning',
            '@message' => 'var_export does not handle circular references',
            '%function' => 'Drupal\\error_test\\Controller\\ErrorTestController->generateWarnings()',
            '%file' => $this->getModulePath('error_test') . '/error_test.module',
        ];
        $error_user_notice = [
            '%type' => 'User warning',
            '@message' => 'Drupal & awesome',
            '%function' => 'Drupal\\error_test\\Controller\\ErrorTestController->generateWarnings()',
            '%file' => $this->getModulePath('error_test') . '/error_test.module',
        ];
        // Set error reporting to display verbose notices.
        $this->config('system.logging')
            ->set('error_level', ERROR_REPORTING_DISPLAY_VERBOSE)
            ->save();
        $this->drupalGet('error-test/generate-warnings');
        $this->assertSession()
            ->statusCodeEquals(200);
        $this->assertErrorMessage($error_notice);
        $this->assertErrorMessage($error_warning);
        $this->assertErrorMessage($error_user_notice);
        $this->assertSession()
            ->responseContains('<pre class="backtrace">');
        // Ensure we are escaping but not double escaping.
        $this->assertSession()
            ->responseContains('&amp;');
        $this->assertSession()
            ->responseNotContains('&amp;amp;');
        // Set error reporting to display verbose notices.
        $this->config('system.logging')
            ->set('error_level', ERROR_REPORTING_DISPLAY_VERBOSE)
            ->save();
        // Set error reporting to collect notices.
        $config->set('error_level', ERROR_REPORTING_DISPLAY_ALL)
            ->save();
        $this->drupalGet('error-test/generate-warnings');
        $this->assertSession()
            ->statusCodeEquals(200);
        $this->assertErrorMessage($error_notice);
        $this->assertErrorMessage($error_warning);
        $this->assertErrorMessage($error_user_notice);
        $this->assertSession()
            ->responseNotContains('<pre class="backtrace">');
        // Set error reporting to not collect notices.
        $config->set('error_level', ERROR_REPORTING_DISPLAY_SOME)
            ->save();
        $this->drupalGet('error-test/generate-warnings');
        $this->assertSession()
            ->statusCodeEquals(200);
        $this->assertNoErrorMessage($error_notice);
        $this->assertErrorMessage($error_warning);
        $this->assertErrorMessage($error_user_notice);
        $this->assertSession()
            ->responseNotContains('<pre class="backtrace">');
        // Set error reporting to not show any errors.
        $config->set('error_level', ERROR_REPORTING_HIDE)
            ->save();
        $this->drupalGet('error-test/generate-warnings');
        $this->assertSession()
            ->statusCodeEquals(200);
        $this->assertNoErrorMessage($error_notice);
        $this->assertNoErrorMessage($error_warning);
        $this->assertNoErrorMessage($error_user_notice);
        $this->assertNoMessages();
        $this->assertSession()
            ->responseNotContains('<pre class="backtrace">');
    }
    
    /**
     * Tests a custom error handler set in settings.php.
     */
    public function testCustomErrorHandler() : void {
        $settings_filename = $this->siteDirectory . '/settings.php';
        chmod($settings_filename, 0777);
        $settings_php = file_get_contents($settings_filename);
        $settings_php .= "\n";
        $settings_php .= "set_error_handler(function() {\n";
        $settings_php .= "  header('HTTP/1.1 418 I\\'m a teapot');\n";
        $settings_php .= "  print('Oh oh, flying teapots from a custom error handler');\n";
        $settings_php .= "  exit();\n";
        $settings_php .= "});\n";
        file_put_contents($settings_filename, $settings_php);
        // For most types of errors, PHP throws an \Error object that Drupal
        // catches, so the error handler is not invoked. To test the error handler,
        // generate warnings, which are not thrown/caught.
        $this->drupalGet('error-test/generate-warnings');
        $this->assertSession()
            ->statusCodeEquals(418);
        $this->assertSession()
            ->responseContains('Oh oh, flying teapots from a custom error handler');
    }
    
    /**
     * Tests the exception handler.
     */
    public function testExceptionHandler() : void {
        $error_exception = [
            '%type' => 'Exception',
            '@message' => 'Drupal & awesome',
            '%function' => 'Drupal\\error_test\\Controller\\ErrorTestController->triggerException()',
            '%line' => 56,
            '%file' => $this->getModulePath('error_test') . '/error_test.module',
        ];
        $error_pdo_exception = [
            '%type' => 'DatabaseExceptionWrapper',
            '@message' => 'SELECT "b".* FROM {bananas_are_awesome} "b"',
            '%function' => 'Drupal\\error_test\\Controller\\ErrorTestController->triggerPDOException()',
            '%line' => 64,
            '%file' => $this->getModulePath('error_test') . '/error_test.module',
        ];
        $error_renderer_exception = [
            '%type' => 'Exception',
            '@message' => 'This is an exception that occurs during rendering',
            '%function' => 'Drupal\\error_test\\Controller\\ErrorTestController->Drupal\\error_test\\Controller\\{closure}()',
            '%line' => 82,
            '%file' => $this->getModulePath('error_test') . '/error_test.module',
        ];
        $this->drupalGet('error-test/trigger-exception');
        $this->assertSession()
            ->statusCodeEquals(500);
        $this->assertErrorMessage($error_exception);
        $this->drupalGet('error-test/trigger-pdo-exception');
        $this->assertSession()
            ->statusCodeEquals(500);
        // We cannot use assertErrorMessage() since the exact error reported
        // varies from database to database. Check that the SQL string is displayed.
        $this->assertSession()
            ->pageTextContains($error_pdo_exception['%type']);
        // Assert statement improved since static queries adds table alias in the
        // error message.
        $this->assertSession()
            ->pageTextContains($error_pdo_exception['@message']);
        $error_details = new FormattableMarkup('in %function (line ', $error_pdo_exception);
        $this->assertSession()
            ->responseContains($error_details);
        $this->drupalGet('error-test/trigger-renderer-exception');
        $this->assertSession()
            ->statusCodeEquals(500);
        $this->assertErrorMessage($error_renderer_exception);
        // Disable error reporting, ensure that 5xx responses are not cached.
        $this->config('system.logging')
            ->set('error_level', ERROR_REPORTING_HIDE)
            ->save();
        $this->drupalGet('error-test/trigger-exception');
        $this->assertSession()
            ->responseHeaderDoesNotExist('X-Drupal-Cache');
        $this->assertSession()
            ->responseHeaderNotContains('Cache-Control', 'public');
        $this->assertSession()
            ->statusCodeEquals(500);
        $this->assertNoErrorMessage($error_exception);
    }
    
    /**
     * Helper function: assert that the error message is found.
     *
     * @internal
     */
    public function assertErrorMessage(array $error) : void {
        $message = new FormattableMarkup('%type: @message in %function (line ', $error);
        $this->assertSession()
            ->responseContains($message);
    }
    
    /**
     * Helper function: assert that the error message is not found.
     *
     * @internal
     */
    public function assertNoErrorMessage(array $error) : void {
        $message = new FormattableMarkup('%type: @message in %function (line ', $error);
        $this->assertSession()
            ->responseNotContains($message);
    }
    
    /**
     * Asserts that no messages are printed onto the page.
     *
     * Ensures that no messages div exists, which proves that no messages were
     * generated by the error handler, not even an empty one.
     *
     * @internal
     */
    protected function assertNoMessages() : void {
        $this->assertSession()
            ->elementNotExists('xpath', '//div[contains(@class, "messages")]');
    }

}