compose.js

const then = Function.call.bind(Promise.prototype.then);

export default (...λs) => (value) => λs.reduce(then, Promise.resolve(value));

usage.js

import compose from './compose';

const request = compose(
  (route) => window.fetch('https://api.service.io' + route),
  (response) => response.json()
);

const getUserNames = compose(
  () => request('/users'),
  (users) => users.filter(user => user.active),
  (users) => users.map(user => user.name)
);

(async () => {
  const users = await getUserNames()
  console.log(users);
})();