Added clouser custom rules support

Author: azeemhassni

src/Envalid.php

@@ -106,7 +106,17 @@ public function validate( $data, $rules )
                 }
 
                 $ruleClass = @$this->rules[ $ruleName ];
-                $valid     = $ruleClass->validate($field, $value, $parsed[ 'args' ]);
+                if (is_callable($ruleClass)) {
+                    $ruleMessage = call_user_func_array($ruleClass, [
+                        $field,
+                        $value,
+                        $parsed[ 'args' ]
+                    ]);
+
+                    $valid = $ruleMessage === true;
+                } else {
+                    $valid = $ruleClass->validate($field, $value, $parsed[ 'args' ]);
+                }
 
                 if (!$ruleMessage) {
                     $ruleMessage = str_replace(['{field}'], $this->labelize($field), $ruleClass->message());
@@ -197,11 +207,16 @@ public function getFields()
      * Register a new Rule to validator
      *
      * @param $id
-     * @param RuleInterface $rule
+     * @param callable|RuleInterface $rule
      * @return $this
+     * @throws \Exception
      */
-    public function addRule( $id, RuleInterface $rule )
+    public function addRule( $id, $rule )
     {
+        if (!is_callable($rule) && !$rule instanceof RuleInterface) {
+            throw new \Exception("Rule must be callable or an instance of " . RuleInterface::class);
+        }
+
         $this->rules[ $id ] = $rule;
         return $this;
     }

tests/ValidatorTest.php

@@ -1,5 +1,7 @@
 <?php namespace azi\Tests;
 
+use azi\Arguments;
+
 /**
  * Tests for azi\Validator
  * Class ValidatorTest
@@ -39,6 +41,23 @@ public function testItSendsMultipleErrorMessagesAtTheSameTime()
         $this->assertEquals('Email must be a valid email address', $errors->get('email')->last());
     }
 
+    public function testItAllowsCallableCustomRules()
+    {
+        $this->validator->addRule('one_to_ten', function ( $field, $value, Arguments $args ) {
+            if ($value >= 1 && $value <= 10) {
+                return true;
+            }
+
+            return "{field} must be between 1-10";
+        });
+
+        $this->validator->validate(['kid_age' => '5'], [
+            'kid_age' => 'one_to_ten'
+        ]);
+
+        $this->assertTrue($this->validator->passed());
+    }
+
     public function testItValidatesRequiredFields()
     {
         $this->validator->validate(['name' => 'Azeem Hassni'], [
@@ -58,6 +77,4 @@ public function testItValidatesEmailFields()
     }
 
 
-
-
 }