imperative-fetch.js

function fetchSomething(thingId) {
  return (dispatch) => {
    // update call metadata
    dispatch(startRequest(thingId))

    return fetch(`https://api.example.com/things/${thingId}`)
    .then((response) => response.json())
    
    // send the result of the call, probably updating the request metadata as well
    .then((json) => dispatch(receiveAThing(json)))
    
    // update the metadata to indicate a failure
    .catch((err) => dispatch(thingGettingFailed(err)))
  }
}