From 181bd92e9553d2fa94ec23bb7f8bfeee193d22bd Mon Sep 17 00:00:00 2001
From: Kkkakania <200867803+Kkkakania@users.noreply.github.com>
Date: Sun, 9 Aug 2026 18:04:09 +0800
Subject: [PATCH] Test lazy execution across deterministic metrics

---
 xskillscore/tests/test_skipna_functionality.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/xskillscore/tests/test_skipna_functionality.py b/xskillscore/tests/test_skipna_functionality.py
index ad7b83bc..a30d6d87 100644
--- a/xskillscore/tests/test_skipna_functionality.py
+++ b/xskillscore/tests/test_skipna_functionality.py
@@ -3,6 +3,7 @@
 
 import numpy as np
 import pytest
+from dask import is_dask_collection
 from xarray.testing import assert_allclose
 
 from xskillscore.core.deterministic import (
@@ -73,6 +74,15 @@ def raise_if_dask_computes(max_computes=0):
 NON_WEIGHTED_METRICS: List[Callable] = [median_absolute_error]
 
 
+@pytest.mark.parametrize("metric", WEIGHTED_METRICS + NON_WEIGHTED_METRICS)
+def test_deterministic_metrics_do_not_compute_chunked_inputs(a_dask, b_dask, metric):
+    """All deterministic metrics preserve lazy execution for chunked inputs."""
+    with raise_if_dask_computes():
+        result = metric(a_dask, b_dask, dim="time", skipna=True)
+
+    assert is_dask_collection(result.data)
+
+
 def drop_nans(a, b, weights=None, dim="time"):
     """
     Masks a and b where they have pairwise nans.