add error testing and fix some shapely things

cf_xarray/geometry.py

@@ -98,11 +98,14 @@ def shapely_to_cf(geometries: Union[xr.DataArray, Sequence], grid_mapping: str =
        - Other variables are not implemented as only Points are currently understood.
     """
     # Get all types to call the appropriate translation function.
-    types = {geom.geom_type for geom in np.asarray(geometries)}
+    types = {
+        geom.item().geom_type if isinstance(geom, xr.DataArray) else geom.geom_type
+        for geom in geometries
+    }
     if types.issubset({"Point", "MultiPoint"}):
         ds = points_to_cf(geometries)
     elif types.issubset({"Polygon", "MultiPolygon"}) or types.issubset(
-        {"Line", "MultiLine"}
+        {"LineString", "MultiLineString"}
     ):
         raise NotImplementedError("Only point geometries conversion is implemented.")
     else:

cf_xarray/tests/test_geometry.py

@@ -51,6 +51,8 @@ def geometry_ds():
 
 @requires_shapely
 def test_shapely_to_cf(geometry_ds):
+    from shapely.geometry import Point
+
     expected, in_ds = geometry_ds
 
     out = xr.merge([in_ds.drop_vars("geometry"), cfxr.shapely_to_cf(in_ds.geometry)])
@@ -81,15 +83,55 @@ def test_shapely_to_cf(geometry_ds):
     assert "longitude" in out.cf
     assert "latitude" in out.cf
 
+    out = cfxr.shapely_to_cf([Point(2, 3)])
+    assert set(out.dims) == {"features", "node"}
+
+
+@requires_shapely
+def test_shapely_to_cf_errors():
+    from shapely.geometry import LineString, Point
+
+    geoms = [LineString([[1, 2], [2, 3]]), LineString([[2, 3, 4], [4, 3, 2]])]
+    with pytest.raises(NotImplementedError, match="Only point geometries conversion"):
+        cfxr.shapely_to_cf(geoms)
+
+    geoms.append(Point(1, 2))
+    with pytest.raises(ValueError, match="Mixed geometry types are not supported"):
+        cfxr.shapely_to_cf(geoms)
+
+    with pytest.raises(
+        NotImplementedError, match="Only grid mapping longitude_latitude"
+    ):
+        cfxr.shapely_to_cf([Point(4, 5)], grid_mapping="albers_conical_equal_area")
+
 
 @requires_shapely
 def test_cf_to_shapely(geometry_ds):
-    in_ds, expected = geometry_ds
+    in_ds, exp = geometry_ds
 
     xr.testing.assert_identical(
-        cfxr.cf_to_shapely(in_ds).drop_vars(["crd_x", "crd_y"]), expected.geometry
+        cfxr.cf_to_shapely(in_ds).drop_vars(["crd_x", "crd_y"]), exp.geometry
     )
 
+    in_ds = in_ds.isel(index=slice(1, None), node=slice(2, None)).drop_vars(
+        "node_count"
+    )
+    del in_ds.geometry_container.attrs["node_count"]
+    out = cfxr.cf_to_shapely(in_ds)
+    assert out.dims == ("index",)
+
+
+@requires_shapely
+def test_cf_to_shapely_errors(geometry_ds):
+    in_ds, expected = geometry_ds
+    in_ds.geometry_container.attrs["geometry_type"] = "line"
+    with pytest.raises(NotImplementedError, match="Only point geometries conversion"):
+        cfxr.cf_to_shapely(in_ds)
+
+    in_ds.geometry_container.attrs["geometry_type"] = "punkt"
+    with pytest.raises(ValueError, match="Valid CF geometry types are "):
+        cfxr.cf_to_shapely(in_ds)
+
 
 @requires_shapely
 def test_reshape_unique_geometries(geometry_ds):
@@ -109,3 +151,8 @@ def test_reshape_unique_geometries(geometry_ds):
     assert out.geometry.dims == ("features",)
     assert out.data.dims == ("features", "time")
     np.testing.assert_array_equal(out.time, [0, 1])
+
+    geoms = in_ds.geometry.expand_dims(n=[1, 2])
+    in_ds = in_ds.assign(geometry=geoms)
+    with pytest.raises(ValueError, match="The geometry variable must be 1D"):
+        cfxr.geometry.reshape_unique_geometries(in_ds)