Rocket.Chat/app/ui/client/components/icon.js

import { FlowRouter } from 'meteor/kadira:flow-router';
import { Template } from 'meteor/templating';

import { baseURI } from '../../../../client/lib/baseURI';

import './icon.html';

const baseUrlFix = () => `${baseURI}${FlowRouter.current().path.substring(1)}`;

const isMozillaFirefoxBelowVersion = (upperVersion) => {
	const [, version] = navigator.userAgent.match(/Firefox\/(\d+)\.\d/) || [];
	return parseInt(version, 10) < upperVersion;
};

const isGoogleChromeBelowVersion = (upperVersion) => {
	const [, version] = navigator.userAgent.match(/Chrome\/(\d+)\.\d/) || [];
	return parseInt(version, 10) < upperVersion;
};

const isBaseUrlFixNeeded = () => isMozillaFirefoxBelowVersion(55) || isGoogleChromeBelowVersion(55);

Template.icon.helpers({
	baseUrl: isBaseUrlFixNeeded() ? baseUrlFix : undefined,
});