pygmt.grdsample: Add check and test for exclusive parameters 'toggle' and 'registration'

pygmt/src/grdsample.py

@@ -106,6 +106,11 @@ def grdsample(
     )
     aliasdict.merge(kwargs)
 
+    # Enforce mutual exclusivity between -T (toggle) and -r (registration)
+    if toggle and aliasdict.get("r") is not None:
+        msg = "Parameters 'toggle' and 'registration' cannot be used together."
+        raise GMTInvalidInput(msg)
+
     with Session() as lib:
         with (
             lib.virtualfile_in(check_kind="raster", data=grid) as vingrd,

pygmt/tests/test_grdsample.py

@@ -8,6 +8,7 @@
 import xarray as xr
 from pygmt import grdsample
 from pygmt.enums import GridRegistration, GridType
+from pygmt.exceptions import GMTInvalidInput
 from pygmt.helpers import GMTTempFile
 from pygmt.helpers.testing import load_static_earth_relief
 
@@ -94,3 +95,11 @@ def test_grdsample_registration_changes(grid):
     assert translated_grid.gmt.registration is GridRegistration.GRIDLINE
     registration_grid = grdsample(grid=translated_grid, registration="p")
     assert registration_grid.gmt.registration is GridRegistration.PIXEL
+
+
+def test_grdsample_toggle_and_registration_mutually_exclusive(grid):
+    """
+    Raise an exception if toggle and registration are both set.
+    """
+    with pytest.raises(GMTInvalidInput):
+        grdsample(grid=grid, toggle=True, registration="p")