root-8.x-1.x-dev/assets/js/messages.js

/**
 * @file
 *   Main JavaScript file for Dismiss module
 */

/* eslint-disable func-names, no-mutable-exports, comma-dangle, strict */

((Drupal, once) => {
  Drupal.behaviors.rootMessages = {
    attach: (context) => {
      Drupal.rootMessages.dismissMessages(context);
    },
  };

  Drupal.rootMessages = {
    dismissMessages: (context = document) => {
      once(
        "root-messages-dismiss",
        ".messages .button--dismiss",
        context
      ).forEach((dismissButton) => {
        dismissButton.addEventListener("click", (e) => {
          e.preventDefault();
          const message = e.currentTarget.closest(".messages-list__item");
          Drupal.rootMessages.hideMessage(message);
        });
      });
    },

    hideMessage: (message) => {
      message.style.opacity = 0;
      message.classList.add("visually-hidden");
    },
  };
})(Drupal, once);