webrtc checking audioinput videoinput

let checking=["audioinput","videoinput"];
let onlyHas={device:[]};
navigator.mediaDevices.enumerateDevices()
.then((devices)=> {
  let haveAllDevices=true;
  devices.forEach((device)=>{
      console.log(device.kind);
      if( device.kind=="audioinput" ){
        onlyHas.audioinput=true;
        }
         if( device.kind=="videoinput" ){
        onlyHas.videoinput=true;
        }
        onlyHas.device.push(device);
    if(!(device.kind==checking[0] || device.kind==checking[1])){
    haveAllDevices=false;
    }
   });
   //do something about ...
})
.catch(function(err) {
  console.log(err.name + ": " + err.message);
});
if(onlyHas.videoinput===false){
    alert('no cam!');
}
if(onlyHas.audioinput===false){
    alert('no microphone!');
}