Test test_missing.py without cftime installed (#5556)

* Test missing without cftime

* Update test_missing.py

* Update test_missing.py

* try importing cftime

* Update test_missing.py

* Update test_missing.py

* Update test_missing.py

* move calender list to init, import from there

* Update test_cftime_offsets.py

* undo test_missing changes for now

* Revert "undo test_missing changes for now"

This reverts commit 6b13cd4.

Author: Illviljan

xarray/tests/__init__.py

@@ -229,3 +229,15 @@ def create_test_data(seed=None, add_attrs=True):
     obj.encoding = {"foo": "bar"}
     assert all(obj.data.flags.writeable for obj in obj.variables.values())
     return obj
+
+
+_CFTIME_CALENDARS = [
+    "365_day",
+    "360_day",
+    "julian",
+    "all_leap",
+    "366_day",
+    "gregorian",
+    "proleptic_gregorian",
+    "standard",
+]

xarray/tests/test_cftime_offsets.py

@@ -26,22 +26,11 @@
     to_cftime_datetime,
     to_offset,
 )
+from xarray.tests import _CFTIME_CALENDARS
 
 cftime = pytest.importorskip("cftime")
 
 
-_CFTIME_CALENDARS = [
-    "365_day",
-    "360_day",
-    "julian",
-    "all_leap",
-    "366_day",
-    "gregorian",
-    "proleptic_gregorian",
-    "standard",
-]
-
-
 def _id_func(param):
     """Called on each parameter passed to pytest.mark.parametrize"""
     return str(param)

xarray/tests/test_missing.py

@@ -14,6 +14,7 @@
 )
 from xarray.core.pycompat import dask_array_type
 from xarray.tests import (
+    _CFTIME_CALENDARS,
     assert_allclose,
     assert_array_equal,
     assert_equal,
@@ -23,7 +24,6 @@
     requires_dask,
     requires_scipy,
 )
-from xarray.tests.test_cftime_offsets import _CFTIME_CALENDARS
 
 
 @pytest.fixture
@@ -542,6 +542,7 @@ def test_get_clean_interp_index_dt(cf_da, calendar, freq):
     np.testing.assert_array_equal(gi, si)
 
 
+@requires_cftime
 def test_get_clean_interp_index_potential_overflow():
     da = xr.DataArray(
         [0, 1, 2],
@@ -592,7 +593,10 @@ def test_interpolate_na_max_gap_errors(da_time):
 
 
 @requires_bottleneck
-@pytest.mark.parametrize("time_range_func", [pd.date_range, xr.cftime_range])
+@pytest.mark.parametrize(
+    "time_range_func",
+    [pd.date_range, pytest.param(xr.cftime_range, marks=requires_cftime)],
+)
 @pytest.mark.parametrize("transform", [lambda x: x, lambda x: x.to_dataset(name="a")])
 @pytest.mark.parametrize(
     "max_gap", ["3H", np.timedelta64(3, "h"), pd.to_timedelta("3H")]