Scraper based on Horseman, written in functional way with Ramda/Folktale.Task

scraper.js

/* global $ document */

const Horseman = require('node-horseman');
const cheerio = require('cheerio');
const R = require('ramda');
const phantomjs = require('phantomjs-prebuilt');

const { Task, mapf } = require('../utils/f.js');

// fetch :: string -> Task Error HTML
const fetch = (url, commands = {}) => {
  return new Task((reject, result) => {
    const horseman = new Horseman({ phantomPath: phantomjs.path });

    horseman
      .viewport(1366, 768)
      .userAgent('Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.94 Safari/537.36') // eslint-disable-line
      .open(url)
      .evaluate((selector) => {
        if (selector) {
          $(selector).click();
        }
      }, commands.click)
      .waitFor((selector) => {
        if (!selector) {
          return true;
        }

        return $(selector).length ? $(selector).is(':hidden') : true;
      }, commands.click, true)
      .evaluate(() => document.documentElement.outerHTML)
      .catch(error => reject(error))
      .then(body => result(body))
      .close();
  });
};

// window :: HTML -> Task Error $
const window = HTML => cheerio.load(HTML);

// dom :: string -> Task Error $
const dom = R.compose(mapf(window), fetch);

// sel :: string -> $ -> [DOMNode]
const sel = R.curry((selector, $) => $(selector));

// absolutize :: string -> string -> string
const absolutize = R.curry((root, href) => {
  return href.startsWith('http') ? href : `${root}${href}`;
});

// toArray :: {} -> []
const toArray = obj => obj.toArray();

// text :: $ -> DOMNode -> string
const text = $ => node => $(node).text();

// attr :: string -> $ -> DOMNode -> string
const attr = attrubute => $ => node => $(node).attr(attrubute);

// selattr -> string -> string -> ($ -> string)
const selattr = (selector, attribute) => R.converge(R.call, [
  attr(attribute),
  sel(selector),
]);

// selarrattr -> string -> string -> ($ -> [string])
const selarrattr = (selector, attribute) => R.converge(R.call, [
  R.compose(R.map, attr(attribute)),
  R.compose(toArray, sel(selector)),
]);

// seltext -> string -> ($ -> string)
const seltext = selector => R.converge(R.call, [
  text,
  sel(selector),
]);

// selarrtext -> string -> ($ -> [string])
const selarrtext = selector => R.converge(R.call, [
  R.compose(R.map, text),
  R.compose(toArray, sel(selector)),
]);

module.exports = {
  fetch,
  window,
  dom,

  selattr,
  selarrattr,
  seltext,
  selarrtext,

  absolutize,
};