add defaults to add_missing_bounds

test add_missing_bounds default

fix default bounds test

tests/test_bounds.py

@@ -78,6 +78,13 @@ def test_adds_x_y_and_z_bounds_to_the_dataset_using_midpoints(self):
         result = ds_no_bnds.bounds.add_missing_bounds(axes=["X", "Y", "Z"])
         assert result.identical(ds)
 
+    def test_adds_default_bounds_to_the_dataset_using_time_frequency(self):
+        ds = generate_dataset_by_frequency(freq="month")
+        ds_no_bnds = ds.drop_vars(["time_bnds", "lat_bnds", "lon_bnds"])
+
+        result = ds_no_bnds.bounds.add_missing_bounds()
+        assert result.identical(ds)
+
     def test_adds_t_bounds_to_the_dataset_using_time_frequency(self):
         ds = generate_dataset_by_frequency(freq="month")
         ds_no_bnds = ds.drop_vars(["time_bnds"])

xcdat/bounds.py

@@ -123,7 +123,9 @@ def keys(self) -> List[str]:
             )
         )
 
-    def add_missing_bounds(self, axes: List[CFAxisKey]) -> xr.Dataset:  # noqa: C901
+    def add_missing_bounds(  # noqa: C901
+        self, axes: List[CFAxisKey] = ["X", "Y", "T"]  # noqa: C901
+    ) -> xr.Dataset:  # noqa: C901
         """Adds missing coordinate bounds for supported axes in the Dataset.
 
         This function loops through the Dataset's axes and attempts to adds