It seems that there is a compatibility issue when moving the library from 2.1 to 3.0 with IE 11

It seems like that IE11 does not support the Arrow function used within this new version

https://github.com/sindresorhus/is-absolute-url/blob/master/test.js#L9

I'd think that it should be false.

Hi @sindresorhus, this might be a very little performance improvement, but it makes the code even clearer. Instead of inlining the regex for testing absolute urls inside the body of the function, it would be better to extract it outside and then referencing it:

const ABSOLUTE_URL_REGEX = /^[a-zA-Z][a-zA-Z\d+\-.]*?:/;

export default function isAbsoluteUrl(url) {
  ...
  return ABSOLUTE_URL_REGEX.test(url);
}

isAbsoluteUrl('javascript:throw%20document.cookie') // true

Although this might be technically correct (?), it seems like it's not what most people would think of as an absolute URL, and it could lead to a false sense of security that the input has been validated as a 'real' URL.

Possible solutions:

• Release a new major version that ensures the protocol is http or https
  • Maybe with an option like { allowNonHttp: true } for people who want the old behaviour.
• Or just add a warning in the readme that this will return true for any protocol, even javascript:.

I'd assume these should be absolute similar to file?

false positive on some windows dir

exemple: C:\Dev\test-broken

https://developer.mozilla.org/en-US/docs/Web/API/URL/canParse_static does basically the same thing

See here for more info.

jonkemp/gulp-useref#37 (comment)

Basically, the regex fails if the 'http' or 'https' is left out. Is it possible to make this work without that?