seq(1)(fn1)(fn2)(fn3).value

seq.js

const _ = require('lodash')

function isPromise(result) {
  return result && (typeof result.then === 'function')
}

function seq(init) {
  let result = typeof init === 'function' ? init() : init
  let properties = {value: {get() { return result }}}
  _.forEach(['then', 'catch', 'finally'], x => { properties[x] = {get() { return (...args) => result[x](...args) }} })

  function chain() {
    function tick(fn, ...args) {
      let partial = _.partial(fn, ...args)
      if (isPromise(result)) result = result.then(r => partial(r))
      else result = partial(result)
      return chain()
    }

    Object.defineProperties(tick, properties)
    return tick
  }

  return chain()
}

module.exports = module.exports.default = seq