Add validator type of file

Author: cdtweb

src/Validator.php

@@ -38,6 +38,7 @@
  * @method static bool isStream(mixed $value, array $rule = []) Checks if value is resource
  * @method static bool isDir(mixed $value, array $rule = []) Checks if value is directory
  * @method static bool isDirectory(mixed $value, array $rule = []) Checks if value is directory
+ * @method static bool isFile(mixed $value, array $rule = []) Checks if value is file
  */
 class Validator
 {
@@ -253,6 +254,10 @@ protected function registerBuiltInTypes()
             'alias' => 'directory',
             'validator' => [$this, 'validateDir']
         ]);
+
+        $this->addType('file', [
+            'validator' => [$this, 'validateFile']
+        ]);
     }
 
     /**
@@ -942,4 +947,30 @@ protected function validateDir($value, array $rule = []): bool
 
         return $valid;
     }
+
+    /**
+     * Validate the $value is a valid file.
+     *
+     * @param $value
+     * @param array $rule
+     * @return bool
+     */
+    protected function validateFile($value, array $rule = []): bool
+    {
+        $valid = is_file($value);
+
+        if ($valid && isset($rule['is_writable']) && $rule['is_writable'] == true) {
+            if (!is_writeable($value)) {
+                $this->setError($rule['name'], "File ($value) must be writable.");
+                return true;
+            }
+        } elseif ($valid && isset($rule['is_writable']) && $rule['is_writable'] == false) {
+            if (is_writeable($value)) {
+                $this->setError($rule['name'], "File ($value) must not be writable.");
+                return true;
+            }
+        }
+
+        return $valid;
+    }
 }