Run the functions in the tasks collection in series, each one running once the previous function has completed

series.js

/**
 * series :: array -> Promise
 *
 * Run the functions in the tasks collection in series,
 * each one running once the previous function has completed.
 */
const series = tasks =>
  tasks.reduce(
    (prevPromise, nextPromise) => prevPromise.then(nextPromise),
    Promise.resolve()
  );

module.exports = {
  series,
};