Parse undefined / null => isValid:true ?

[lqzhgood]

tldjs.parse(undefined)
isValid:true

tldjs.parse(null)
isValid:true

[remusao]

Hi @lqzhgood, thanks for taking the time to open an issue. Unfortunately this is "expected" behavior. For backward compatibility reasons any value passed to tld.js which is not a string, will be converted to a string. That happens there: https://github.com/oncletom/tld.js/blob/master/lib/clean-host.js#L76

If the values you are manipulated are already hostnames, you can override this step completely using a custom extractHostname function:

const tldjs = require('tldjs');

tldjs.parse(undefined);
// { hostname: 'undefined',
//   isValid: true,
//   isIp: false,
//   tldExists: false,
//   publicSuffix: null,
//   domain: null,
//   subdomain: null }

const custom = tldjs.fromUserSettings({ extractHostname: (hostname) => hostname });
custom.parse(undefined)
// { hostname: undefined,
//   isValid: false,
//   isIp: false,
//   tldExists: false,
//   publicSuffix: null,
//   domain: null,
//   subdomain: null }

Note that you could also use this customization to implement your own URL parsing (e.g.: using the URL API from Node.js):

const URL = require('url').URL;
const tldjs = require('tldjs').fromUserSettings({ extractHostname: (url) => new URL(url).hostname });

tldjs.parse(undefined);
// Thrown:
// { TypeError [ERR_INVALID_URL]: Invalid URL: undefined
//     at onParseError (internal/url.js:241:17)
//     at new URL (internal/url.js:319:5)
//     at extractHostname (repl:1:60)
//     at Object.parse (/home/remi/dev/repositories/public/tld.js/index.js:52:17) input: 'undefined' }

tldjs.parse('https://foo.com/bar')
// { hostname: 'foo.com',
//   isValid: true,
//   isIp: false,
//   tldExists: true,
//   publicSuffix: 'com',
//   domain: 'foo.com',
//   subdomain: '' }

I hope this helps!

[lqzhgood]

in https://github.com/oncletom/tld.js/blob/master/lib/clean-host.js#L68

extractHostname Why not first check if the url is correct? like this

module.exports = function extractHostname(value) {
  if (!isNaN(value)) {
    return null;
  }
  if (typeof value !== 'string') {
    return null;
  }

  // First check if `value` is already a valid hostname.
  if (isValid(value)) {
    return trimTrailingDots(value);
  }

  var url = value;

  var needsTrimming = checkTrimmingNeeded(url);
......

tld.parse(null)
tld.parse(undefined)
tld.parse(() => {})
{
    "hostname": null,
    "isValid": false,
    "isIp": false,
    "tldExists": false,
    "publicSuffix": null,
    "domain": null,
    "subdomain": null
}

That looks fine. And there's nothing wrong with that run npm run test

And I have one more question that I'm not sure about。
1234 Are pure Numbers is domain names in RFC?
if not . https://github.com/oncletom/tld.js/blob/master/lib/is-valid.js#L40 add judge.

module.exports = function isValid(hostname) {
  if (!isNaN(hostname)) {
    return false;
  }
  if (typeof hostname !== 'string') {
    return false;
  }
...

[remusao]

@lqzhgood All good suggestions. Feel free to make a PR to the repository with improvements, but there was not much activity around lately. I currently maintain my own fork of this project.