More URL checks

[hemanth]

My editor has formatted the code, I hope you are ok with it.

The actual change is this.

//cc @tj

[radiovisual]

Unless TJ is wanting to keep this module dependency-free, may I suggest that you use the module url-regex for checking url patterns? The RegExp you supplied is pretty good, and catches all the most typical patterns, but it fails on protocol-less urls, such as 'www.google.com/foo':

/^(?:\w+:)?\/\/([^\s\.]+\.\S{2}|localhost[\:?\d]*)\S*$/.test('www.google.com/foo');
//=> false

But more importantly, your supplied RegExp lets some invalid url patterns through. Consider the following code:

var urlRegExp = /^(?:\w+:)?\/\/([^\s\.]+\.\S{2}|localhost[\:?\d]*)\S*$/;

var invalidUrls = [
     'http://-error-.invalid/',
     'http://-a.b.co',
     'http://a.b-.co',
     'http://123.123.123',
     'http://go/ogle.com',
     'http://google\.com',
     'http://www(google.com',
     'http://www.example.xn--overly-long-punycode-test-string-test-tests-123-test-test123/',
     'http://www=google.com',
     '///www.foo.bar./'
];

invalidUrls.forEach(function(url) {
    // these should all be `false`
    var isUrl = urlRegExp.test(url);
    console.log(isUrl);
});

Which results in the following output (these should all read false):

true
true
true
true
true
true
true
true
true
true

The url-regex module is pretty good at keeping up-to-date, and is pretty complete by most standards.

Full disclosure: To arrive at this conclusion, I ran your UrlRegExp against all the urls in the url-regex test file for comparison purposes, this is how I was able to catch some of the invalid patterns, and see that it was failing on protocol-less urls.