Template for unit tests

tests/conftest.py

@@ -2,7 +2,9 @@
 import shutil
 from pathlib import Path
 
+import pandas as pd
 import pytest
+import xarray as xr
 
 notebooks = Path().cwd().parent / "docs" / "notebooks"
 
@@ -20,3 +22,29 @@ def remove_data_folder():
             shutil.rmtree(data)
 
     request.addfinalizer(remove_data_folder)
+
+
+@pytest.fixture
+def tas_series_1d():
+    """Create a temperature time series."""
+
+    def _tas_series(values, start="7/1/2000", units="K", freq="D", as_dataset=True):
+        coords = pd.date_range(start, periods=len(values), freq=freq)
+        da = xr.DataArray(
+            values,
+            coords=[coords],
+            dims="time",
+            name="tas",
+            attrs={
+                "standard_name": "air_temperature",
+                "cell_methods": "time: mean within days",
+                "units": units,
+            },
+        )
+        da.name = "tas"
+        if as_dataset:
+            return da.to_dataset()
+        else:
+            return da
+
+    return _tas_series

tests/test_aggregate.py

@@ -0,0 +1,13 @@
+import numpy as np
+
+from xscen import aggregate
+
+
+class TestClimatologicalMean:
+    def test_monthly_all_default(self, tas_series_1d):
+        ds = tas_series_1d(
+            np.tile(np.arange(1, 13), 3), start="2001-01-01", freq="MS", as_dataset=True
+        )
+        out = aggregate.climatological_mean(ds)
+        assert out.attrs["cat:processing_level"] == "climatology"
+        np.testing.assert_array_equal(out.tas, np.arange(1, 13))

xscen/aggregate.py

@@ -70,6 +70,11 @@ def climatological_mean(
         Returns a Dataset of the climatological mean
 
     """
+    if xr.infer_freq(ds.time) == "D":
+        raise NotImplementedError(
+            "xs.climatological_mean does not currently support daily data."
+        )
+
     # there is one less occurrence when a period crosses years
     freq_across_year = [
         f"{f}-{mon}"