- Merged getValue override

src/Query/OrderBy.php

@@ -10,6 +10,8 @@ class OrderBy extends Fragment {
     const SQL_TOKEN = "ORDER BY";
     const SQL_COLLATE = "COLLATE";
 
+    # const 'NULLS LAST|FIRST' must be handlded
+
     public function set(array $order) : self
     {
         $this->orderBy = $order;
@@ -17,9 +19,9 @@ class OrderBy extends Fragment {
         return $this;
     }
 
-    public function add(string|\Stringable $field, ? string $direction = null) : self
+    public function add(string|\Stringable $field, string|\Stringable|null $direction = null) : self
     {
-        $this->validateFieldType($field);
+        $this->validateDirectionType($direction);
 
         $this->orderBy[] = [ $field, $direction ];
         
@@ -39,4 +41,10 @@ class OrderBy extends Fragment {
         ]);
     }
 
+    protected function validateDirectionType(mixed $direction) {
+        # Could be coming from user-input, we must whitelist
+        if (is_string($direction) && ! in_array(strtoupper($direction), [ 'ASC', 'DESC' ])) {
+            throw new \Ulmus\Exception\InvalidFieldType(sprintf("Validation of string `%s` failed from query `%s`", $direction, get_class($this)));
+        }
+    }
 }