fix: report partition_names in validation errors instead of the internal key

pymilvus/client/async_grpc_handler.py

@@ -1037,7 +1037,7 @@ async def search(
             limit=limit,
             round_decimal=round_decimal,
             anns_field=anns_field,
-            partition_name_array=partition_names,
+            partition_names=partition_names,
             output_fields=output_fields,
             guarantee_timestamp=kwargs.get("guarantee_timestamp"),
             timeout=timeout,
@@ -1103,7 +1103,7 @@ async def hybrid_search(
         check_pass_param(
             limit=limit,
             round_decimal=round_decimal,
-            partition_name_array=partition_names,
+            partition_names=partition_names,
             output_fields=output_fields,
             guarantee_timestamp=kwargs.get("guarantee_timestamp"),
             timeout=timeout,
@@ -1390,7 +1390,7 @@ async def release_partitions(
         **kwargs,
     ):
         check_pass_param(
-            collection_name=collection_name, partition_name_array=partition_names, timeout=timeout
+            collection_name=collection_name, partition_names=partition_names, timeout=timeout
         )
         request = Prepare.release_partitions("", collection_name, partition_names)
         response = await self._async_stub.ReleasePartitions(

pymilvus/client/check.py

@@ -353,6 +353,8 @@ def __init__(self) -> None:
             "nlist": is_legal_nlist,
             "cmd": is_legal_cmd,
             "partition_name": is_legal_partition_name,
+            "partition_names": is_legal_partition_name_array,
+            # Kept so callers still passing the internal name keep validating.
             "partition_name_array": is_legal_partition_name_array,
             "limit": is_legal_limit,
             "anns_field": is_legal_anns_field,

pymilvus/client/grpc_handler.py

@@ -1420,7 +1420,7 @@ def search(
             limit=limit,
             round_decimal=round_decimal,
             anns_field=anns_field,
-            partition_name_array=partition_names,
+            partition_names=partition_names,
             output_fields=output_fields,
             guarantee_timestamp=kwargs.get("guarantee_timestamp"),
             timeout=timeout,
@@ -1481,7 +1481,7 @@ def hybrid_search(
         check_pass_param(
             limit=limit,
             round_decimal=round_decimal,
-            partition_name_array=partition_names,
+            partition_names=partition_names,
             output_fields=output_fields,
             guarantee_timestamp=kwargs.get("guarantee_timestamp"),
             timeout=timeout,
@@ -2177,7 +2177,7 @@ def release_partitions(
         **kwargs,
     ):
         check_pass_param(
-            collection_name=collection_name, partition_name_array=partition_names, timeout=timeout
+            collection_name=collection_name, partition_names=partition_names, timeout=timeout
         )
         request = Prepare.release_partitions("", collection_name, partition_names)
         response = self._stub.ReleasePartitions(

pymilvus/client/prepare.py

@@ -618,7 +618,7 @@ def show_partitions_request(
         partition_names: Optional[List[str]] = None,
         type_in_memory: bool = False,
     ):
-        check_pass_param(collection_name=collection_name, partition_name_array=partition_names)
+        check_pass_param(collection_name=collection_name, partition_names=partition_names)
         req = milvus_types.ShowPartitionsRequest(collection_name=collection_name)
         if partition_names:
             if not isinstance(partition_names, (list,)):
@@ -637,15 +637,15 @@ def show_partitions_request(
     def get_loading_progress(
         cls, collection_name: str, partition_names: Optional[List[str]] = None
     ):
-        check_pass_param(collection_name=collection_name, partition_name_array=partition_names)
+        check_pass_param(collection_name=collection_name, partition_names=partition_names)
         req = milvus_types.GetLoadingProgressRequest(collection_name=collection_name)
         if partition_names:
             req.partition_names.extend(partition_names)
         return req
 
     @classmethod
     def get_load_state(cls, collection_name: str, partition_names: Optional[List[str]] = None):
-        check_pass_param(collection_name=collection_name, partition_name_array=partition_names)
+        check_pass_param(collection_name=collection_name, partition_names=partition_names)
         req = milvus_types.GetLoadStateRequest(collection_name=collection_name)
         if partition_names:
             req.partition_names.extend(partition_names)
@@ -2250,7 +2250,7 @@ def load_partitions(
         )
 
         if partition_names:
-            check_pass_param(partition_name_array=partition_names)
+            check_pass_param(partition_names=partition_names)
             req.partition_names.extend(partition_names)
 
         if replica_number:

tests/unit/prepare/test_collection.py

@@ -555,3 +555,21 @@ def test_error_on_empty_drop_identifier(self, kwargs):
     def test_error_on_multiple_drop_identifiers(self, kwargs):
         with pytest.raises(ParamError, match="exactly one valid Drop identifier"):
             Prepare.alter_collection_schema_request(collection_name="coll", **kwargs)
+
+
+class TestLoadPartitionsRequest:
+    """Tests for load_partitions."""
+
+    def test_rejects_invalid_partition_names_by_their_public_name(self):
+        """The error must name `partition_names`, the argument the caller actually passed.
+
+        The validator was registered under the internal key `partition_name_array`, and the
+        message is built from that registry key, so callers were told a parameter name that
+        appears nowhere in the public API (#2589).
+        """
+        with pytest.raises(ParamError, match=r"`partition_names` value \['p1', 1\] is illegal"):
+            Prepare.load_partitions("coll", ["p1", 1])
+
+    def test_accepts_valid_partition_names(self):
+        req = Prepare.load_partitions("coll", ["p1", "p2"])
+        assert list(req.partition_names) == ["p1", "p2"]

tests/unit/test_client_validators.py

@@ -261,6 +261,26 @@ def test_not_list(self):
         assert is_legal_partition_name_array("p1") is False
 
 
+class TestPartitionNamesErrorMessage:
+    def test_reports_the_public_parameter_name(self):
+        """The message must name `partition_names`, the argument callers actually pass.
+
+        The checker was registered under the internal key `partition_name_array`, and
+        `_raise_param_error` formats the registry key straight into the message, so an
+        invalid value reported a name that appears nowhere in the public API (#2589).
+        """
+        with pytest.raises(ParamError, match=r"`partition_names` value 1 is illegal"):
+            check_pass_param(partition_names=1)
+
+    def test_valid_value_passes(self):
+        check_pass_param(partition_names=["p1", "p2"])
+
+    def test_internal_key_still_validates(self):
+        """Back-compat: anything still passing the old key keeps being checked."""
+        with pytest.raises(ParamError, match=r"`partition_name_array` value 1 is illegal"):
+            check_pass_param(partition_name_array=1)
+
+
 class TestIsLegalDropRatio:
     def test_valid(self):
         assert is_legal_drop_ratio(0.5) is True