Konami code using rx

konamiRx.js

Rx.Observable.fromEvent(document.body, 'keyup')
.map((event) => event.keyCode)
.bufferCount(7)
.subscribe((buffer) => {
  const keymap = [ 77,73,82,65,78,68,65 ];
  const cond = buffer.every((v,i)=> v === keymap[i])

  if(cond){
    const dialog = this.shadowRoot.querySelector('#debug');
    dialog.open();
  }    
});