URL fun

package.json

{
  "version": "0.3.0",
  "name": "url-fun",
  "description": "URL fun",
  "main": "url-fun.js",
  "author": "pinkhominid <pinkhominid@birdbomb.com>",
  "license": "MIT",
  "homepage": "https://gist.github.com/pinkhominid/742ff38688f7638d4eb795048b620e8e"
}

url-fun.js

export function toAbsUrl(rel, base) {
  return (new URL(rel, base)).toString()
}

export function toRelUrl(abs) {
  const url = new URL(abs);
  return url.toString().substring(url.origin.length);
};

export function isLocalUrl(url) {
  const { hostname } = new URL(url);
  return /^(localhost|127\.0\.0\.1|0\.0\.0\.0)$/.test(hostname);
}

export function getSecondAndTopLevelDomain(url) {
  const { hostname } = new URL(url);
  // TODO: if (isIP(hostname)) return undefined;
  return hostname.replace(/^.*(\b[^.]+\.[^.]+)$/, '$1');
}

export function areUrlOriginsEqual(url1, url2) {
  const u1 = new URL(url1);
  const u2 = new URL(url2);
  return u1.origin === u2.origin;
}

const trailingSlashesPathReplacePtn = /\/+$/;
// trailing slash path insensitive equality
export function areUrlsEqualish(url1, url2) {
  const u1 = new URL(url1);
  const u2 = new URL(url2);
  u1.pathname = u1.pathname.replace(trailingSlashesPathReplacePtn, '');
  u2.pathname = u2.pathname.replace(trailingSlashesPathReplacePtn, '');
  return u1.toString() === u2.toString();
}

export function mergeURLSearchParams(...paramCollections) {
  let paramsObj;
  for (const collection of paramCollections) {
    paramsObj = { ...paramsObj, ...Object.fromEntries(new URLSearchParams(collection)) };
  }
  return new URLSearchParams(paramsObj).toString();
}

npm i gist:742ff38688f7638d4eb795048b620e8e