Allow port rule to be optional

app/Rules/Port.php

@@ -8,26 +8,30 @@ use Illuminate\Contracts\Validation\ValidationRule;
 
 class Port implements ValidationRule
 {
-    /**
-     * Run the validation rule.
-     *
-     * @param  \Closure(string): \Illuminate\Translation\PotentiallyTranslatedString  $fail
-     */
     public function validate(string $attribute, mixed $value, Closure $fail): void
     {
+        // Allow port to be optional
+        if (empty($value)) {
+            return;
+        }
+
+        // Require port to be a number
         if (!is_numeric($value)) {
             $fail('The :attribute must be numeric.');
         }
 
+        // Require port to be an integer
         $value = intval($value);
         if (floatval($value) !== (float) $value) {
             $fail('The :attribute must be an integer.');
         }
 
+        // Require minimum valid port
         if ($value <= Endpoint::PORT_FLOOR) {
             $fail('The :attribute must be greater than 1024.');
         }
 
+        // Require maximum valid port
         if ($value > Endpoint::PORT_CEIL) {
             $fail('The :attribute must be less than 65535.');
         }