add tests

esmf_regrid/esmf_regridder.py

@@ -19,6 +19,8 @@
 def _get_regrid_weights_dict(src_field, tgt_field, regrid_method, esmf_args=None):
     if esmf_args is None:
         esmf_args = {}
+    else:
+        esmf_args = esmf_args.copy()
     # Provide default values
     if "ignore_degenerate" not in esmf_args:
         esmf_args["ignore_degenerate"] = True

esmf_regrid/schemes.py

@@ -299,7 +299,6 @@ def _regrid_along_dims(data, regridder, dims, num_out_dims, mdtol):
 
 
 def _check_esmf_args(kwargs):
-    # TODO: raise proper warning messages
     if kwargs is not None:
         if not isinstance(kwargs, dict):
             raise TypeError(f"Expected `esmf_args` to be a dict, got a {type(kwargs)}.")
@@ -328,10 +327,10 @@ def _check_esmf_args(kwargs):
         ]
         for kwarg in kwargs.keys():
             if kwarg in invalid_kwargs:
-                msg = f"{kwarg} is not an argument which can be controlled by `esmf_args`."
+                msg = f"`esmpy.Regrid` argument `{kwarg}` cannot be controlled by `esmf_args`."
                 raise ValueError(msg)
             if kwarg not in valid_kwargs:
-                msg = f"{kwarg} is not a valid argument for `esmpy.Regrid`."
+                msg = f"`{kwarg}` is not a valid argument for `esmpy.Regrid`."
                 raise ValueError(msg)
 
 
@@ -1438,7 +1437,7 @@ def __init__(
         use_src_mask=False,
         use_tgt_mask=False,
         tgt_location=None,
-        esmf_args=None,
+        esmf_args={},
         **kwargs,
     ):
         """
@@ -1620,7 +1619,7 @@ def __init__(
         use_src_mask=False,
         use_tgt_mask=False,
         tgt_location="face",
-        esmf_args=None,
+        esmf_args={},
     ):
         """
         Create regridder for conversions between ``src`` and ``tgt``.
@@ -1707,7 +1706,7 @@ def __init__(
         use_tgt_mask=False,
         tgt_location=None,
         extrapolate_gaps=False,
-        esmf_args=None,
+        esmf_args={},
     ):
         """
         Create regridder for conversions between ``src`` and ``tgt``.
@@ -1776,7 +1775,7 @@ def __init__(
         use_src_mask=False,
         use_tgt_mask=False,
         tgt_location=None,
-        esmf_args=None,
+        esmf_args={},
     ):
         """
         Create regridder for conversions between ``src`` and ``tgt``.

esmf_regrid/tests/unit/schemes/__init__.py

@@ -12,6 +12,7 @@
     _gridlike_mesh,
     _gridlike_mesh_cube,
 )
+from esmf_regrid import esmpy
 
 
 def _test_cube_regrid(scheme, src_type, tgt_type):
@@ -252,3 +253,54 @@ def _test_dtype_handling(scheme, src_type, tgt_type, in_dtype):
 
     assert result.lazy_data().dtype == expected_dtype
     assert result.data.dtype == expected_dtype
+
+def _test_esmf_args(scheme):
+    """Test regridding scheme handles esmf_args as expected."""
+    n_lons_src = 6
+    n_lons_tgt = 3
+    n_lats_src = 4
+    n_lats_tgt = 2
+    lon_bounds = (-180, 180)
+    lat_bounds = (-90, 90)
+
+    src = _grid_cube(n_lons_src, n_lats_src, lon_bounds, lat_bounds, circular=True)
+    tgt = _grid_cube(n_lons_tgt, n_lats_tgt, lon_bounds, lat_bounds, circular=True)
+
+    valid_esmf_args = {
+        "unmapped_action": esmpy.UnmappedAction.ERROR,
+        "ignore_degenerate": False,
+        "line_type": esmpy.LineType.CART,
+        "large_file": True,
+    }
+
+    rg_1 = scheme(esmf_args=valid_esmf_args).regridder(src, tgt)
+    rg_2 = scheme().regridder(src, tgt, esmf_args=valid_esmf_args)
+
+    assert rg_1.esmf_args == valid_esmf_args
+    assert rg_2.esmf_args == valid_esmf_args
+
+    invalid_esmf_args_duplicate = {
+        "regrid_method": None
+    }
+    invalid_esmf_args_incorrect = {
+        "invalid_arg": None
+    }
+    invalid_esmf_args_type = "invalid_arg"
+
+    match_duplicate = "cannot be controlled by `esmf_args`"
+    with pytest.raises(ValueError, match=match_duplicate):
+        rg = scheme(esmf_args=invalid_esmf_args_duplicate)
+    with pytest.raises(ValueError, match=match_duplicate):
+        rg = scheme().regridder(src, tgt, esmf_args=invalid_esmf_args_duplicate)
+
+    match_incorrect = "is not a valid argument for"
+    with pytest.raises(ValueError, match=match_incorrect):
+        rg = scheme(esmf_args=invalid_esmf_args_incorrect)
+    with pytest.raises(ValueError, match=match_incorrect):
+        rg = scheme().regridder(src, tgt, esmf_args=invalid_esmf_args_incorrect)
+
+    match_type = "Expected `esmf_args` to be a dict, got a "
+    with pytest.raises(TypeError, match=match_type):
+        rg = scheme(esmf_args=invalid_esmf_args_type)
+    with pytest.raises(TypeError, match=match_type):
+        rg = scheme().regridder(src, tgt, esmf_args=invalid_esmf_args_type)

esmf_regrid/tests/unit/schemes/test_ESMFAreaWeighted.py

@@ -6,6 +6,7 @@
 from esmf_regrid.tests.unit.schemes.__init__ import (
     _test_cube_regrid,
     _test_dtype_handling,
+    _test_esmf_args,
     _test_invalid_mdtol,
     _test_mask_from_init,
     _test_mask_from_regridder,
@@ -81,3 +82,8 @@ def test_dtype_handling(src_tgt_types, in_dtype):
     """Test regridding scheme handles dtype as expected."""
     src_type, tgt_type = src_tgt_types
     _test_dtype_handling(ESMFAreaWeighted, src_type, tgt_type, in_dtype)
+
+
+def test_esmf_args():
+    """Test regridding scheme handles esmf_args as expected."""
+    _test_esmf_args(ESMFAreaWeighted)

esmf_regrid/tests/unit/schemes/test_ESMFBilinear.py

@@ -6,6 +6,7 @@
 from esmf_regrid.tests.unit.schemes.__init__ import (
     _test_cube_regrid,
     _test_dtype_handling,
+    _test_esmf_args,
     _test_invalid_mdtol,
     _test_mask_from_init,
     _test_mask_from_regridder,
@@ -70,3 +71,7 @@ def test_dtype_handling(src_tgt_types, in_dtype):
     """Test regridding scheme handles dtype as expected."""
     src_type, tgt_type = src_tgt_types
     _test_dtype_handling(ESMFBilinear, src_type, tgt_type, in_dtype)
+
+def test_esmf_args():
+    """Test regridding scheme handles esmf_args as expected."""
+    _test_esmf_args(ESMFBilinear)

esmf_regrid/tests/unit/schemes/test_ESMFBilinearRegridder.py

@@ -9,6 +9,7 @@
     _curvilinear_cube,
     _grid_cube,
 )
+from esmf_regrid import esmpy
 
 
 def test_dim_switching():
@@ -329,3 +330,36 @@ def test_regrid_data():
     )
     result = rg(src)
     np.testing.assert_allclose(expected_data, result.data)
+
+def test_extrapolate_gaps():
+    n_lons = 6
+    n_lats = 5
+    src_lon_bounds = (-140, 180)
+    tgt_lon_bounds = (-180, 180)
+    src_lat_bounds = (-80, 90)
+    tgt_lat_bounds = (-90, 90)
+    src = _grid_cube(n_lons, n_lats, src_lon_bounds, src_lat_bounds, circular=False)
+    src.data = np.arange(n_lons * n_lats).reshape(n_lats, n_lons)
+    tgt = _grid_cube(n_lons, n_lats, tgt_lon_bounds, tgt_lat_bounds, circular=True)
+
+    extrapolate_regridder = ESMFBilinearRegridder(
+        src, tgt, extrapolate_gaps=True
+    )
+    normal_regridder = ESMFBilinearRegridder(
+        src, tgt, extrapolate_gaps=False
+    )
+
+    extrapolate_result = extrapolate_regridder(src)
+    normal_result = normal_regridder(src)
+
+    assert not np.ma.is_masked(extrapolate_result.data)
+    assert np.ma.is_masked(normal_result.data)
+
+    expected_args = {
+    "extrap_method": esmpy.ExtrapMethod.NEAREST_IDAVG,
+    "extrap_num_src_pnts": 2,
+    "extrap_dist_exponent": 1,
+}
+    assert extrapolate_regridder.esmf_args == expected_args
+    assert normal_regridder.esmf_args == {}
+

esmf_regrid/tests/unit/schemes/test_ESMFNearest.py

@@ -7,6 +7,7 @@
 from esmf_regrid.schemes import ESMFNearest
 from esmf_regrid.tests.unit.schemes.__init__ import (
     _test_dtype_handling,
+    _test_esmf_args,
     _test_mask_from_init,
     _test_mask_from_regridder,
     _test_non_degree_crs,
@@ -113,3 +114,8 @@ def test_dtype_handling(src_tgt_types, in_dtype):
     """Test regridding scheme handles dtype as expected."""
     src_type, tgt_type = src_tgt_types
     _test_dtype_handling(ESMFNearest, src_type, tgt_type, in_dtype)
+
+
+def test_esmf_args():
+    """Test regridding scheme handles esmf_args as expected."""
+    _test_esmf_args(ESMFNearest)