From 86c00a402543428d44a6c7be5ddfbe7f53e10516 Mon Sep 17 00:00:00 2001
From: nishantharkut <nhnishantharkut@gmail.com>
Date: Tue, 17 Mar 2026 11:26:52 +0530
Subject: [PATCH 1/2] fix: correct warnings.warn arguments in deprecated
 assign_ugrid_topology wrapper

Swap the warning message and category arguments in the utils compatibility wrapper so DeprecationWarning is emitted correctly. Add stacklevel=2 so the warning points to user call sites, and add a regression test that checks warning category, message content, and caller filename.
---
 tests/test_utils.py         | 22 ++++++++++++++++++++++
 xarray_subset_grid/utils.py |  3 ++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/tests/test_utils.py b/tests/test_utils.py
index 6b64a2c..0612460 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -1,9 +1,11 @@
 import os
+import warnings
 
 import numpy as np
 import pytest
 
 from xarray_subset_grid.utils import (
+    assign_ugrid_topology,
     normalize_bbox_x_coords,
     normalize_polygon_x_coords,
     ray_tracing_numpy,
@@ -125,3 +127,23 @@ def test_ray_tracing_numpy():
     result = ray_tracing_numpy(points[:, 0], points[:, 1], poly)
 
     assert np.array_equal(result, [False, True, False])
+
+
+def test_assign_ugrid_topology_warns_with_deprecation_warning(monkeypatch):
+    def fake_assign_ugrid_topology(*args, **kwargs):
+        return "ok"
+
+    monkeypatch.setattr(
+        "xarray_subset_grid.grids.ugrid.assign_ugrid_topology",
+        fake_assign_ugrid_topology,
+    )
+
+    with warnings.catch_warnings(record=True) as caught:
+        warnings.simplefilter("always")
+        result = assign_ugrid_topology(None)
+
+    assert result == "ok"
+    assert len(caught) == 1
+    assert caught[0].category is DeprecationWarning
+    assert "assign_grid_topology" in str(caught[0].message)
+    assert os.path.basename(caught[0].filename) == "test_utils.py"
diff --git a/xarray_subset_grid/utils.py b/xarray_subset_grid/utils.py
index e004525..c1e6f06 100644
--- a/xarray_subset_grid/utils.py
+++ b/xarray_subset_grid/utils.py
@@ -97,10 +97,11 @@ def ray_tracing_numpy(x, y, poly):
 # this placeholder for backwards compatibility for a brief period
 def assign_ugrid_topology(*args, **kwargs):
     warnings.warn(
-        DeprecationWarning,
         "The function `assign_grid_topology` has been moved to the "
         "`grids.ugrid` module. It will not be able to be called from "
         "the utils `module` in the future.",
+        DeprecationWarning,
+        stacklevel=2,
     )
     from .grids.ugrid import assign_ugrid_topology
 

From da740510cedd252c34fc9d3071fc2ff62ab7c373 Mon Sep 17 00:00:00 2001
From: nishantharkut <nhnishantharkut@gmail.com>
Date: Tue, 17 Mar 2026 13:34:27 +0530
Subject: [PATCH 2/2] fix: address review feedback - correct function name in
 deprecation message

Apply Copilot review suggestions:
- Fix function name in warning message: change assign_grid_topology to assign_ugrid_topology (the correct function name in the repo)
- Remove backticks around second occurrence of 'module' (plain English word, not code reference)
- Use keyword argument category=DeprecationWarning instead of positional argument
- Update test assertion to match corrected message
---
 tests/test_utils.py         | 2 +-
 xarray_subset_grid/utils.py | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/test_utils.py b/tests/test_utils.py
index 0612460..115d9a2 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -145,5 +145,5 @@ def fake_assign_ugrid_topology(*args, **kwargs):
     assert result == "ok"
     assert len(caught) == 1
     assert caught[0].category is DeprecationWarning
-    assert "assign_grid_topology" in str(caught[0].message)
+    assert "assign_ugrid_topology" in str(caught[0].message)
     assert os.path.basename(caught[0].filename) == "test_utils.py"
diff --git a/xarray_subset_grid/utils.py b/xarray_subset_grid/utils.py
index c1e6f06..1c50ea3 100644
--- a/xarray_subset_grid/utils.py
+++ b/xarray_subset_grid/utils.py
@@ -97,10 +97,10 @@ def ray_tracing_numpy(x, y, poly):
 # this placeholder for backwards compatibility for a brief period
 def assign_ugrid_topology(*args, **kwargs):
     warnings.warn(
-        "The function `assign_grid_topology` has been moved to the "
+        "The function `assign_ugrid_topology` has been moved to the "
         "`grids.ugrid` module. It will not be able to be called from "
-        "the utils `module` in the future.",
-        DeprecationWarning,
+        "the utils module in the future.",
+        category=DeprecationWarning,
         stacklevel=2,
     )
     from .grids.ugrid import assign_ugrid_topology