The evolution of a moderately-complicated fetch request

evolution-of-a-fetch.js

// Assume `fetch` and `notify` are defined elsewhere.

// ## 1. CPS With Nodebacks

function fetchAppState() {
  return function(dispatch) {
    fetch(function(err, data) {
      if (err) {
        console.error('Poop', err);
        return;
      }
      
      dispatch(data);
    });
  }
}

// ## 2. ES6ification

const fetchAppState = () => (dispatch) => 
  fetch((err, data) => {
    if (err) {
      console.error('Poop', err);
      return;
    }

    dispatch(data);
  });

// ## 3. Promisified fetch

const fetchAppState = () => (dispatch) => 
  fetch()
    then(dispatch)
    catch((err) => {
      console.error('Poop', err);
    });

// ## 4. Flatten code further with async/await

const fetchAppState = () => (dispatch) => {
  try {
    dispatch(await fetch());
  } catch (poop) {
    console.error('Poop', poop);
  }
}