copy.js

import { crocks, R } from './deps.js';

const { Async } = crocks;
const { compose, prop, last } = R;
const FINISHED = '__FINISHED__';
const lastId = compose(prop('id'), last);
const isOk = (result) => result.ok ? Async.of(result) : Async.Rejected('Error Copying Data');
const checkFinished = (limit) => (xs) => xs.length === limit ? lastId(xs) : FINISHED;
/**
 * @param {Async} list
 * @param {Async} bulk
 */
export default function (list, bulk) {
  /**
   * @param {Number} limit
   * @param {string} startkey
   */
  return function (limit, startkey) {
    return Async.of({ limit, startkey })
      .chain(list)
      .map(prop('docs'))
      .chain(bulk)
      .chain(isOk)
      .map(prop('results'))
      .map(checkFinished(limit));
  };
}