Add the validation for empty texts.

gliner_inference_server/helpers.py

@@ -27,18 +27,45 @@ def validate_single_or_batch(text: Optional[str], texts: Optional[List[str]]):
             }
         )
 
+    if text == "" and texts is None:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail={
+                "error": {
+                    "code": "INVALID_INPUT",
+                    "message": "'text' cannot be empty or only whitespace",
+                    "details": {}
+                }
+            }
+        )
+
     if texts is not None and len(texts) == 0:
         raise HTTPException(
             status_code=status.HTTP_400_BAD_REQUEST,
             detail={
                 "error": {
                     "code": "INVALID_INPUT",
-                    "message": "texts list cannot be empty",
+                    "message": "Texts list cannot be empty",
                     "details": {}
                 }
             }
         )
 
+    if texts is not None and len(texts) != 0:
+        # Check for empty strings within the list
+        for i, t in enumerate(texts):
+            if not isinstance(t, str) or not t.strip():
+                raise HTTPException(
+                    status_code=status.HTTP_400_BAD_REQUEST,
+                    detail={
+                        "error": {
+                            "code": "INVALID_INPUT",
+                            "message": f"Text item at index {i} in 'texts' cannot be empty or only whitespace",
+                            "details": {}
+                        }
+                    }
+                )
+
     return text if text is not None else texts