trait HtmlOutputPrinterTrait

trait HtmlOutputPrinterTrait {
    
    /**
     * File to write html links to.
     *
     * @var string
     */
    protected $browserOutputFile;
    
    /**
     * {@inheritdoc}
     */
    public function __construct($out = NULL, $verbose = FALSE, $colors = self::COLOR_DEFAULT, $debug = FALSE, $numberOfColumns = 80, $reverse = FALSE) {
        parent::__construct($out, $verbose, $colors, $debug, $numberOfColumns, $reverse);
        $this->setUpHtmlOutput();
    }
    
    /**
     * Creates the file to list the HTML output created during the test.
     *
     * @see \Drupal\Tests\BrowserTestBase::initBrowserOutputFile()
     */
    protected function setUpHtmlOutput() {
        if ($html_output_directory = getenv('BROWSERTEST_OUTPUT_DIRECTORY')) {
            // Initialize html output debugging.
            $html_output_directory = rtrim($html_output_directory, '/');
            // Check if directory exists.
            if (!is_dir($html_output_directory) || !is_writable($html_output_directory)) {
                $this->writeWithColor('bg-red, fg-black', "HTML output directory {$html_output_directory} is not a writable directory.");
            }
            else {
                // Convert to a canonicalized absolute pathname just in case the current
                // working directory is changed.
                $html_output_directory = realpath($html_output_directory);
                $this->browserOutputFile = tempnam($html_output_directory, 'browser_output_');
                if ($this->browserOutputFile) {
                    touch($this->browserOutputFile);
                }
                else {
                    $this->writeWithColor('bg-red, fg-black', "Unable to create a temporary file in {$html_output_directory}.");
                }
            }
        }
        if ($this->browserOutputFile) {
            putenv('BROWSERTEST_OUTPUT_FILE=' . $this->browserOutputFile);
        }
        else {
            // Remove any environment variable.
            putenv('BROWSERTEST_OUTPUT_FILE');
        }
    }
    
    /**
     * Prints the list of HTML output generated during the test.
     */
    protected function printHtmlOutput() {
        if ($this->browserOutputFile) {
            $contents = file_get_contents($this->browserOutputFile);
            if ($contents) {
                $this->writeNewLine();
                $this->writeWithColor('bg-yellow, fg-black', 'HTML output was generated');
                $this->write($contents);
            }
            // No need to keep the file around any more.
            unlink($this->browserOutputFile);
        }
    }
    
    /**
     * Prints HTML output links for the Simpletest UI.
     */
    public function simpletestUiWrite($buffer) {
        $buffer = Html::escape($buffer);
        // Turn HTML output URLs into clickable link <a> tags.
        $url_pattern = '@https?://[^\\s]+@';
        $buffer = preg_replace($url_pattern, '<a href="$0" target="_blank" title="$0">$0</a>', $buffer);
        // Make the output readable in HTML by breaking up lines properly.
        $buffer = nl2br($buffer);
        print $buffer;
    }

}