Change conditions for Domain validation

Domains can have `--` as long as they don't start or end with `-` in its
parts.

Author: henriquemoody

library/Rules/Domain.php

@@ -29,16 +29,12 @@ public function __construct($tldCheck = true)
             new Alnum('-'),
             new Not(new StartsWith('-')),
             new OneOf(
-                new Not(
-                    new Contains('--')
-                ),
-                new AllOf(
-                    new StartsWith('xn--'),
-                    new Callback(function ($str) {
-                        return substr_count($str, '--') == 1;
-                    })
-                )
-            )
+                new Not(new Contains('--')),
+                new Callback(function ($str) {
+                    return substr_count($str, '--') == 1;
+                })
+            ),
+            new Not(new EndsWith('-'))
         );
     }
 

tests/unit/Rules/DomainTest.php

@@ -67,6 +67,9 @@ public function providerForDomain()
             ['xn--bcher-kva.ch'],
             ['mail.xn--bcher-kva.ch'],
             ['example-hyphen.com'],
+            ['example--valid.com'],
+            ['std--a.com'],
+            ['r--w.com'],
         ];
     }
 
@@ -76,10 +79,10 @@ public function providerForNotDomain()
             [null],
             [''],
             ['2222222domain.local'],
-            ['example--invalid.com'],
             ['-example-invalid.com'],
             ['example.invalid.-com'],
             ['xn--bcher--kva.ch'],
+            ['example.invalid-.com'],
             ['1.2.3.256'],
             ['1.2.3.4'],
         ];