From 151bd531a5b94eb644624402844879d243312951 Mon Sep 17 00:00:00 2001
From: Madeesh Kannan <shadeMe@users.noreply.github.com>
Date: Thu, 19 Sep 2024 15:03:04 +0200
Subject: [PATCH] feat: Add utility function to check metadata filter syntax
 (#8386)

---
 haystack/utils/filters.py | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/haystack/utils/filters.py b/haystack/utils/filters.py
index 8cdf294ffb..a24affaf1b 100644
--- a/haystack/utils/filters.py
+++ b/haystack/utils/filters.py
@@ -4,7 +4,7 @@
 
 from dataclasses import fields
 from datetime import datetime
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Optional
 
 import pandas as pd
 
@@ -12,6 +12,15 @@
 from haystack.errors import FilterError
 
 
+def raise_on_invalid_filter_syntax(filters: Optional[Dict[str, Any]] = None):
+    """
+    Raise an error if the filter syntax is invalid.
+    """
+    if filters and "operator" not in filters and "conditions" not in filters:
+        msg = "Invalid filter syntax. See https://docs.haystack.deepset.ai/docs/metadata-filtering for details."
+        raise ValueError(msg)
+
+
 def document_matches_filter(filters: Dict[str, Any], document: Document) -> bool:
     """
     Return whether `filters` match the Document.