repo_description: Promise based HTTP client for the browser and node.js
repo_topics: hacktoberfest http-client javascript nodejs promise
code: 'use strict';
  
  import utils from '../utils.js';
  import AxiosURLSearchParams from '../helpers/AxiosURLSearchParams.js';
  
  /**
   * It replaces URL-encoded forms of `:`, `$`, `,`, and spaces with
   * their plain counterparts (`:`, `$`, `,`, `+`).
   *
   * @param {string} val The value to be encoded.
   *
   * @returns {string} The encoded value.
   */
  function encode(val) {
    return encodeURIComponent(val)
      .replace(/%3A/gi, ':')
      .replace(/%24/g, '$')
      .replace(/%2C/gi, ',')
      .replace(/%20/g, '+');
  }
  
  /**
   * Build a URL by appending params to the end
   *
   * @param {string} url The base of the url (e.g., http://www.google.com)
   * @param {object} [params] The params to be appended
   * @param {?(object|Function)} options
   *
   * @returns {string} The formatted url
   */
  export default function buildURL(url, params, options) {
    if (!params) {
      return url;
    }
  
    const _encode = (options && options.encode) || encode;
  
    const _options = utils.isFunction(options)
      ? {
          serialize: options,
        }
      : options;
  
    const serializeFn = _options && _options.serialize;
  
    let serializedParams;
  
    if (serializeFn) {
      serializedParams = serializeFn(params, _options);
    } else {
      serializedParams = utils.isURLSearchParams(params)
        ? params.toString()
        : new AxiosURLSearchParams(params, _options).toString(_encode);
    }
  
    if (serializedParams) {
      const hashmarkIndex = url.indexOf('#');
  
      if (hashmarkIndex !== -1) {
        url = url.slice(0, hashmarkIndex);
      }
      url += (url.indexOf('?') === -1 ? '?' : '&') + serializedParams;
    }
  
    return url;
  }
  