Oinktube/node_modules/inputmask/lib/inputmaskElement.js

import window from "./global/window";
import Inputmask from "./inputmask";
import canUseDOM from "./canUseDOM";

const document = window.document;

// add check if it is supported by the browser
// integrate shadowroot into maskcope
if (canUseDOM && document && document.head && document.head.attachShadow && window.customElements && window.customElements.get("input-mask") === undefined) {
	class InputmaskElement extends HTMLElement {
		constructor() {
			super();
			var attributeNames = this.getAttributeNames(),
				shadow = this.attachShadow({mode: "closed"}),
				input = document.createElement("input");
			input.type = "text";
			shadow.appendChild(input);

			for (var attr in attributeNames) {
				if (Object.prototype.hasOwnProperty.call(attributeNames, attr)) {
					input.setAttribute(attributeNames[attr], this.getAttribute(attributeNames[attr]));
				}
			}

			var im = new Inputmask();
			im.dataAttribute = "";
			im.mask(input);
			input.inputmask.shadowRoot = shadow; //make the shadowRoot available
		}
	}

	window.customElements.define("input-mask", InputmaskElement);
}