[JavaScript] A vanilla JS url parser.

url-parser.js

/**
 * @license
 * Copyright (c) 2017, Luca Bertolasi. All Rights Reserved.
 *
 * This source code is licensed under the terms of the MIT license,
 * a copy of which can be found at https://choosealicense.com/licenses/mit/
 */

function urlParser(url) {
  // fallback to location object if no arg has been provided
  url = url === undefined ? window.location.href : url

  // validate type
  if (typeof url !== `string`
  // validate pattern | source: https://gist.github.com/dperini/729294
  || url.match(/^(?:(?:https?|ftp):\/\/)( ?:\S+(?::\S*)?@)?(?:(?!(?:10|127)(?:\.\d{1,3}){3})(?!(?:169\.254|192\.168)(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[a-z\u00a1-\uffff]{2,}))\.?)(?::\d{2,5})?(?:[/?#]\S*)?$/i) === null) {
    throw new TypeError(`'${url}' is not a valid url`)
  }

  // parse url | source: https://news.ycombinator.com/item?id=12172180
  const A = document.createElement('a')
  A.href = url  // "https://www.domain.io:8080/path?pa=1&ram=2#fragment"

  // extract query params as map
  const queryParams = new Map()
  if (A.search.length > 0) {
    A.search.split('?')[1].split('&').map(queryParam => {
      [key, value] = queryParam.split('=')
      queryParams.set(key, value)
    })
  }
  // [alternative] extract query params as array
  // const queryParams = A.search.length > 0 ? A.search.split('?')[1].split('&').map(queryParam => [key, value] = queryParam.split('=')) : []

  return {
    url:          A.href,      // "https://www.domain.io:8080/path?pa=1&ram=2#fragment"
    origin:       A.origin,    // "https://www.domain.io:8080"
    protocol:     A.protocol,  // "https"
    host:         A.host,      // "www.domain.io:8080"
    hostname:     A.hostname,  // "www.domain.io"
    port:         A.port,      // "8080"
    pathname:     A.pathname,  // "/path"
    hash:         A.hash,      // "#fragment"
    query_params: queryParams  // {"pa" => "1", "ram" => "2"}  // to get the number of query params, use property 'size'
    // query_params: queryParams  // [["pa", "1"], ["ram", "2"]]  // to get the number of query params, use property 'length'
  }
}