Simple PHP Error-handler

ErrorHandler.php

/**
 * Simple error-handler mapping PHP errors to PHP's ErrorException, and registering
 * a global exception-handler that slightly improves Exception display.
 *
 * @see ErrorException
 */
class ErrorHandler
{
    /**
     * Register error-handler and Exception-handler.
     */
    public function __construct()
    {
        // Convert PHP errors to ErrorException:

        set_error_handler(function ($errno, $errstr, $errfile, $errline) {
            if (error_reporting() === 0) {
                return; // error-suppression operator was used - do not throw.
            }
            
            throw new ErrorException($errstr, 0, $errno, $errfile, $errline);
        });

        // Improve Exception display in HTML response:

        set_exception_handler(function (Exception $e) {
            $html = true;

            foreach (headers_list() as $header) {
                if ((stripos($header, 'content-type:') === 0) && (stripos($header, 'html') === false)) {
                    $html = false; // a non-html content-type has been set
                }
            }

            echo $html
                ? '<pre>' . htmlspecialchars($e->__toString()) . '</pre>'
                : $e->__toString();
        });
    }
}