fetchPoll.js

function *pollForWeatherInfo(){
  while (true) {
    yield fetch('/api/currentWeather', {
      method: 'get'
    }).then(res => res.json())
  }
}

function runPolling(generator){
  if (!generator) {
    generator = pollForWeatherInfo()
  }

  const p = generator.next()

  p.value.then(d => {
    if (!d.temperature) {
      runPolling(generator)
    } else {
      console.log(d)
    }
  })
}