fix: reject zero query limits

test/collection/test_queries.py

@@ -3,8 +3,10 @@
 import pytest
 
 from weaviate.collections.query import _QueryCollectionAsync
+from weaviate.collections.grpc.query import _QueryGRPC
 from weaviate.connect import ConnectionV4
 from weaviate.exceptions import WeaviateInvalidInputError
+from weaviate.util import _ServerVersion
 
 # TODO: re-enable tests once string syntax is re-enabled in the API
 
@@ -88,6 +90,35 @@ async def _test_query(query: Awaitable) -> None:
         await query()
 
 
+def _grpc_query(validate_arguments: bool = True) -> _QueryGRPC:
+    return _QueryGRPC(
+        weaviate_version=_ServerVersion.from_string("1.38.13"),
+        name="Dummy",
+        tenant=None,
+        consistency_level=None,
+        validate_arguments=validate_arguments,
+        uses_125_api=True,
+        uses_127_api=True,
+    )
+
+
+def test_query_limit_zero_is_rejected() -> None:
+    with pytest.raises(WeaviateInvalidInputError, match="limit must be greater than zero"):
+        _grpc_query().get(limit=0)
+
+
+@pytest.mark.parametrize("limit", [None, 1])
+def test_query_limit_boundary_is_accepted(limit: int | None) -> None:
+    request = _grpc_query().get(limit=limit)
+    assert request.limit == (limit or 0)
+
+
+def test_query_limit_zero_keeps_legacy_behavior_without_validation() -> None:
+    zero = _grpc_query(validate_arguments=False).get(limit=0)
+    omitted = _grpc_query(validate_arguments=False).get()
+    assert zero.SerializeToString() == omitted.SerializeToString()
+
+
 @pytest.mark.asyncio
 async def test_bad_query_inputs(connection: ConnectionV4) -> None:
     query = _QueryCollectionAsync(connection, "dummy", None, None, None, None, True)

weaviate/collections/grpc/query.py

@@ -45,6 +45,7 @@
 )
 from weaviate.collections.filters import _FilterToGRPC
 from weaviate.collections.grpc.shared import _BaseGRPC
+from weaviate.exceptions import WeaviateInvalidInputError
 from weaviate.proto.v1 import base_search_pb2, search_get_pb2
 from weaviate.types import NUMBER, UUID
 from weaviate.util import _ServerVersion
@@ -470,6 +471,8 @@ def __create_request(
                     ),
                 ]
             )
+            if limit == 0:
+                raise WeaviateInvalidInputError("Query limit must be greater than zero")
             if isinstance(return_properties, Sequence):
                 for prop in return_properties:
                     _validate_input(