Various HTTP related utilities in node js, specifically in Typescript

HttpUtils.ts

import { Request } from 'express';

function isTrue(value) {
  return ['1', 1, 'yes', 'true', 'on'].indexOf(value) > -1;
}

function booleanValue(value) {
  if (value) {
    return ['1', 1, 'yes', 'true', 'on'].indexOf(value) > -1;
  }
  return undefined;
}

function getBaseUrl(req: Request) {
  let proto = req.headers['x-forwarded-proto'] || req.protocol;
  if (proto && Array.isArray(proto)) {
    proto = proto[0];
  }

  let host = req.headers['x-forwarded-host'] || req.get('host');
  if (host && Array.isArray(host)) {
    host = host[0];
  }

  let url = proto + '://' + host;
  let port = req.get('port');
  if (port) {
    url += ':' + port;
  }
  return url;
}

function getRemoteHost(req: Request) {
  return req.headers['x-forwarded-for'] || req.connection.remoteAddress;
}

export { 
  isTrue,
  booleanValue,
  isRefererSameSite,
  getBaseUrl,
  getRemoteHost
};