From 879af5950049ef791388e2ec7d672e7dbe107387 Mon Sep 17 00:00:00 2001
From: Deepak Cherian <deepak@cherian.net>
Date: Thu, 14 Nov 2024 20:58:56 -0700
Subject: [PATCH] cftime tests

---
 xarray/groupers.py           |  4 ++--
 xarray/tests/test_groupby.py | 26 +++++++++++++++++++++-----
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/xarray/groupers.py b/xarray/groupers.py
index 3c657884634..3a1ea1aebea 100644
--- a/xarray/groupers.py
+++ b/xarray/groupers.py
@@ -876,8 +876,8 @@ def factorize(self, group: T_Group) -> EncodedGroups:
 
         # all years and seasons
         def get_label(year, season):
-            month = season_tuples[season][0]
-            return f"{year}-{month}-01"
+            month, *_ = season_tuples[season]
+            return f"{year}-{month:02d}-01"
 
         unique_codes = np.arange(len(unique_coord))
         valid_season_mask = season_label != ""
diff --git a/xarray/tests/test_groupby.py b/xarray/tests/test_groupby.py
index a8fb905100a..ca27b3643d6 100644
--- a/xarray/tests/test_groupby.py
+++ b/xarray/tests/test_groupby.py
@@ -3182,13 +3182,21 @@ def test_season_resampling_raises_unsorted_seasons(self, seasons):
         with pytest.raises(ValueError, match="sort"):
             da.resample(time=SeasonResampler(seasons))
 
-    # TODO: drop_incomplete
-    @requires_cftime
+    @pytest.mark.parametrize(
+        "use_cftime",
+        [
+            pytest.param(
+                True, marks=pytest.mark.skipif(not has_cftime, reason="no cftime")
+            ),
+            False,
+        ],
+    )
     @pytest.mark.parametrize("drop_incomplete", [True, False])
     @pytest.mark.parametrize(
         "seasons",
         [
             pytest.param(["DJF", "MAM", "JJA", "SON"], id="standard"),
+            pytest.param(["NDJ", "FMA", "MJJ", "ASO"], id="nov-first"),
             pytest.param(["MAM", "JJA", "SON", "DJF"], id="standard-diff-order"),
             pytest.param(["JFM", "AMJ", "JAS", "OND"], id="december-same-year"),
             pytest.param(["DJF", "MAM", "JJA", "ON"], id="skip-september"),
@@ -3196,9 +3204,17 @@ def test_season_resampling_raises_unsorted_seasons(self, seasons):
             pytest.param(["MAM", "JJA", "SON", "DJF"], id="different-order"),
         ],
     )
-    def test_season_resampler(self, seasons: list[str], drop_incomplete: bool) -> None:
+    def test_season_resampler(
+        self, seasons: list[str], drop_incomplete: bool, use_cftime: bool
+    ) -> None:
         calendar = "standard"
-        time = date_range("2001-01-01", "2002-12-30", freq="D", calendar=calendar)
+        time = date_range(
+            "2001-01-01",
+            "2002-12-30",
+            freq="D",
+            calendar=calendar,
+            use_cftime=use_cftime,
+        )
         da = DataArray(np.ones(time.size), dims="time", coords={"time": time})
         counts = da.resample(time="ME").count()
 
@@ -3239,7 +3255,7 @@ def test_season_resampler(self, seasons: list[str], drop_incomplete: bool) -> No
             # we construct expected in the standard calendar
             xr.DataArray(expected_vals, dims="time", coords={"time": expected_time})
             # and then convert to the expected calendar,
-            .convert_calendar(calendar, align_on="date")
+            .convert_calendar(calendar, align_on="date", use_cftime=use_cftime)
             # and finally sort since DJF will be out-of-order
             .sortby("time")
         )