Use ArrayLength in select() and filter your query by the length with where().

Author: TCB13

src/QueryBuilder.php

@@ -23,6 +23,7 @@ class QueryBuilder
     private $result;
 
     private $fields = [];
+    private $addFields = [];
     private $limit = 0;
     private $skip = 0;
     private $count = [];
@@ -114,6 +115,10 @@ public function findAll(): self
             $pipeline[] = $this->unwind;
         }
 
+        if (!empty($this->addFields)) {
+            $pipeline[] = ["\$addFields" => $this->addFields];
+        }
+
         if (empty(!$this->filters)) {
             $pipeline[] = [
                 "\$match" => $this->getNormalizedFilters()
@@ -164,7 +169,9 @@ public function select($fields): self
             }
             // ArrayLength Function or COUNT feature
             if ($field instanceof ArrayLength /*|| $field instanceof Count*/) {
-                return $field->asArray();
+                $arrayLen = $field->asArray();
+                $this->addFields[] = $arrayLen;
+                return [key($arrayLen) => 1];
             }
             return $field;
         }, $fields);
@@ -182,6 +189,10 @@ public function select($fields): self
             $this->fields = call_user_func_array("array_merge", $this->fields);
         }
 
+        if (count($this->addFields)) {
+            $this->addFields = call_user_func_array("array_merge", $this->addFields);
+        }
+
         // Exclude built in _id if not set in fields - MongoDB always returns this by default
         if (!in_array("_id", $fields)) {
             $this->fields["_id"] = 0;