fetch_parallel.js

    const getInvite = fetch(                                                                                           
      `${apiHost}/invite/?event=${event_id}&user=${userId}`                                                               
    );                                                                                                                    
    const getHost = fetch(`${apiHost}/user/${event.fields.host}/`);                                                       
    Promise.all([getInvite, getHost, delayPromise(1000)()])                                                               
      .then(values => {                                                                                                    
        values.pop(); // drop delayPromise's return value (undefined)                                                     
        return values.map(v => v.json());                                                                                 
      })                                                                                                                  
      .then(responses => {                                                                                    
        inviteResponse = responses[0];                                                                                  
        invite = inviteResponse[0];                                                                                     
        hostResponse = responses[1];                                                                                    
        host = hostResponse[0];                                                                                           
        this.setState({ fetching: false, host, invite });                                                                                
      })                                                                                                                  
      .catch(error => console.error(error));