@openactive/rpde-validator/src/helpers/url-helper.js

A library to walk and validate an RPDE feed

const fetch = require('node-fetch');
const { URL } = require('url');

const TimeoutError = require('../errors/timeout-error');

class UrlHelper {
  static deriveUrl(url, base) {
    if (typeof url !== 'string') {
      return '';
    }
    let urlRaw = url;
    if (!urlRaw.match(/^http/)) {
      if (urlRaw.match(/^\//)) {
        const currentUrl = new URL(base);
        urlRaw = `${currentUrl.origin}${urlRaw}`;
      }
    }
    return urlRaw;
  }

  static getParam(param, url, base) {
    const derivedUrl = this.deriveUrl(url, base);
    let urlObj;
    try {
      urlObj = new URL(derivedUrl);
    } catch (e) {
      return null;
    }
    return urlObj.searchParams.get(param);
  }

  static findParamInWrongCase(param, url, base) {
    const derivedUrl = this.deriveUrl(url, base);
    let urlObj;
    try {
      urlObj = new URL(derivedUrl);
    } catch (e) {
      return null;
    }
    for (const i of urlObj.searchParams.keys()) {
      if (i !== param && i.toLowerCase() === param.toLowerCase()) {
        return i;
      }
    }
    return null;
  }

  static fetch(url, options = {}, timeout = 10000) {
    let timeoutId;
    return Promise.race([
      fetch(url, options).then(
        (res) => {
          clearTimeout(timeoutId);
          return res;
        },
      ),
      new Promise((_, reject) => {
        timeoutId = setTimeout(
          () => reject(new TimeoutError(`Request to ${url} timed out after ${timeout}ms`)),
          timeout,
        );
      }),
    ]);
  }

  static isUrl(url) {
    if (typeof url !== 'string') {
      return false;
    }
    return UrlHelper.URL_REGEX.test(url);
  }
}

// Source: adapted from https://gist.github.com/dperini/729294
UrlHelper.URL_REGEX = new RegExp('^'
    // protocol identifier (mandatory)
    // short syntax // not permitted
    + '(?:(?:https?):\\/\\/)'
    + '(?:'
      // IP address dotted notation octets
      // excludes loopback network 0.0.0.0
      // excludes reserved space >= 224.0.0.0
      // excludes network & broadcast addresses
      // (first & last IP address of each class)
      + '(?:[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]))'
    + '|'
      // Include localhost
      + 'localhost'
    + '|'
      // host & domain names, may end with dot
      // can be replaced by a shortest alternative
      // (?![-_])(?:[-\\w\\u00a1-\\uffff]{0,63}[^-_]\\.)+
      + '(?:'
        + '(?:'
          + '[a-z0-9\\u00a1-\\uffff]'
          + '[a-z0-9\\u00a1-\\uffff_-]{0,62}'
        + ')?'
        + '[a-z0-9\\u00a1-\\uffff]\\.'
      + ')+'
      // TLD identifier name, may end with dot
      + '(?:[a-z\\u00a1-\\uffff]{2,}\\.?)'
    + ')'
    // port number (optional)
    + '(?::\\d{2,5})?'
    // resource path (optional)
    + '(?:[/?#]\\S*)?'
  + '$', 'i');

module.exports = UrlHelper;