dynamic import

external-files.js

export class ExternalFiles{
    constructor() {
        this.getChat();
        this.getCalendar();
    }
    async getChat(){
        if(!customElements.get('foo-chat')){
            await import('chat/chat.js');
        }
    }
    async getCalendar(){
        if(!customElements.get('foo-calendar')){
            await import('calendar/calendar.js');
        }
    }
}
new ExternalFiles();