Add an option to allow no host, this closes #563

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 - Added support for IPv6 in `isURL()`
   ([#564](https://github.com/chriso/validator.js/issues/564))
+- Added support for urls without a host (e.g. `file:///foo.txt`) in `isURL()`
+  ([#563](https://github.com/chriso/validator.js/issues/563))
 - Added support for MasterCard 2-Series BIN
   ([#576](https://github.com/chriso/validator.js/pull/576))
 - New locales

README.md

@@ -92,7 +92,7 @@ Passing anything other than a string is an error.
 - **isNull(str)** - check if the string is null (has a length of zero).
 - **isNumeric(str)** - check if the string contains only numbers.
 - **isSurrogatePair(str)** - check if the string contains any surrogate pairs chars.
-- **isURL(str [, options])** - check if the string is an URL. `options` is an object which defaults to `{ protocols: ['http','https','ftp'], require_tld: true, require_protocol: false, require_valid_protocol: true, allow_underscores: false, host_whitelist: false, host_blacklist: false, allow_trailing_dot: false, allow_protocol_relative_urls: false }`.
+- **isURL(str [, options])** - check if the string is an URL. `options` is an object which defaults to `{ protocols: ['http','https','ftp'], require_tld: true, require_protocol: false, require_host: true, require_valid_protocol: true, allow_underscores: false, host_whitelist: false, host_blacklist: false, allow_trailing_dot: false, allow_protocol_relative_urls: false }`.
 - **isUUID(str [, version])** - check if the string is a UUID (version 3, 4 or 5).
 - **isUppercase(str)** - check if the string is uppercase.
 - **isVariableWidth(str)** - check if the string contains a mixture of full and half-width chars.

lib/isURL.js

@@ -27,6 +27,7 @@ var default_url_options = {
   protocols: ['http', 'https', 'ftp'],
   require_tld: true,
   require_protocol: false,
+  require_host: true,
   require_valid_protocol: true,
   allow_underscores: false,
   allow_trailing_dot: false,
@@ -74,6 +75,11 @@ function isURL(url, options) {
 
   split = url.split('/');
   url = split.shift();
+
+  if (url === '' && !options.require_host) {
+    return true;
+  }
+
   split = url.split('@');
   if (split.length > 1) {
     auth = split.shift();

src/lib/isURL.js

@@ -8,6 +8,7 @@ const default_url_options = {
   protocols: ['http', 'https', 'ftp'],
   require_tld: true,
   require_protocol: false,
+  require_host: true,
   require_valid_protocol: true,
   allow_underscores: false,
   allow_trailing_dot: false,
@@ -48,6 +49,11 @@ export default function isURL(url, options) {
 
   split = url.split('/');
   url = split.shift();
+
+  if (url === '' && !options.require_host) {
+    return true;
+  }
+
   split = url.split('@');
   if (split.length > 1) {
     auth = split.shift();

test/validators.js

@@ -248,6 +248,24 @@ describe('Validators', function () {
     });
   });
 
+  it('should validate file URLs without a host', function () {
+    test({
+      validator: 'isURL',
+      args: [{
+        protocols: ['file'],
+        require_host: false,
+      }],
+      valid: [
+        'file://localhost/foo.txt',
+        'file:///foo.txt',
+        'file:///',
+      ],
+      invalid: [
+        'http://foobar.com',
+      ],
+    });
+  });
+
   it('should validate URLs with any protocol', function () {
     test({
       validator: 'isURL',

validator.js

@@ -295,6 +295,7 @@
         protocols: ['http', 'https', 'ftp'],
         require_tld: true,
         require_protocol: false,
+        require_host: true,
         require_valid_protocol: true,
         allow_underscores: false,
         allow_trailing_dot: false,
@@ -342,6 +343,11 @@
 
         split = url.split('/');
         url = split.shift();
+
+        if (url === '' && !options.require_host) {
+          return true;
+        }
+
         split = url.split('@');
         if (split.length > 1) {
           auth = split.shift();