Merge branch 'main' into test-unification

Author: max-sixty

xarray/tests/test_rolling.py

@@ -510,6 +510,29 @@ def test_rolling_exp_keep_attrs(self, da, func) -> None:
         ):
             da.rolling_exp(time=10, keep_attrs=True)
 
+    @pytest.mark.parametrize("func", ["mean", "sum"])
+    @pytest.mark.parametrize("min_periods", [1, 20])
+    def test_cumulative(self, da, func, min_periods) -> None:
+        # One dim
+        result = getattr(da.cumulative("time", min_periods=min_periods), func)()
+        expected = getattr(
+            da.rolling(time=da.time.size, min_periods=min_periods), func
+        )()
+        assert_identical(result, expected)
+
+        # Multiple dim
+        result = getattr(da.cumulative(["time", "a"], min_periods=min_periods), func)()
+        expected = getattr(
+            da.rolling(time=da.time.size, a=da.a.size, min_periods=min_periods),
+            func,
+        )()
+        assert_identical(result, expected)
+
+    def test_cumulative_vs_cum(self, da) -> None:
+        result = da.cumulative("time").sum()
+        expected = da.cumsum("time")
+        assert_identical(result, expected)
+
 
 class TestDatasetRolling:
     @pytest.mark.parametrize(
@@ -834,6 +857,25 @@ def test_raise_no_warning_dask_rolling_assert_close(self, ds, name) -> None:
         expected = getattr(getattr(ds.rolling(time=4), name)().rolling(x=3), name)()
         assert_allclose(actual, expected)
 
+    @pytest.mark.parametrize("func", ["mean", "sum"])
+    @pytest.mark.parametrize("ds", (2,), indirect=True)
+    @pytest.mark.parametrize("min_periods", [1, 10])
+    def test_cumulative(self, ds, func, min_periods) -> None:
+        # One dim
+        result = getattr(ds.cumulative("time", min_periods=min_periods), func)()
+        expected = getattr(
+            ds.rolling(time=ds.time.size, min_periods=min_periods), func
+        )()
+        assert_identical(result, expected)
+
+        # Multiple dim
+        result = getattr(ds.cumulative(["time", "x"], min_periods=min_periods), func)()
+        expected = getattr(
+            ds.rolling(time=ds.time.size, x=ds.x.size, min_periods=min_periods),
+            func,
+        )()
+        assert_identical(result, expected)
+
 
 @requires_numbagg
 class TestDatasetRollingExp: