From c2414bbf09a951515adc0248ecd420b884a7f83f Mon Sep 17 00:00:00 2001
From: thodson-usgs <thodson@usgs.gov>
Date: Fri, 17 Apr 2026 16:25:23 -0500
Subject: [PATCH] Fix three latent bugs in Grid construction and mode
 regridders

- utils.create_lat_lon_coords: check remainder against resolution_lon (not
  resolution_lat) for the longitude span, so non-square grids no longer
  overshoot `east`.
- Grid.__post_init__: the `south > north` branch now reports the correct
  bound in the error message, and the second check uses `elif` so the
  first failure isn't silently overwritten. Drops a stray `pass`.
- regrid.most_common / regrid.least_common: the Dataset-input error message
  was a tuple (trailing comma on the first string literal), so ValueError
  printed unreadably. Remove the comma so the message is a single string.
---
 src/xarray_regrid/regrid.py | 8 ++++----
 src/xarray_regrid/utils.py  | 7 +++----
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/xarray_regrid/regrid.py b/src/xarray_regrid/regrid.py
index b2ed389..d34eb72 100644
--- a/src/xarray_regrid/regrid.py
+++ b/src/xarray_regrid/regrid.py
@@ -164,10 +164,10 @@ def most_common(
 
         if isinstance(self._obj, xr.Dataset):
             msg = (
-                "The 'most common value' regridder is not implemented for\n",
+                "The 'most common value' regridder is not implemented for\n"
                 "xarray.Dataset, as it requires specifying the expected labels.\n"
                 "Please select only a single variable (as DataArray),\n"
-                " and regrid it separately.",
+                " and regrid it separately."
             )
             raise ValueError(msg)
 
@@ -216,10 +216,10 @@ def least_common(
 
         if isinstance(self._obj, xr.Dataset):
             msg = (
-                "The 'least common value' regridder is not implemented for\n",
+                "The 'least common value' regridder is not implemented for\n"
                 "xarray.Dataset, as it requires specifying the expected labels.\n"
                 "Please select only a single variable (as DataArray),\n"
-                " and regrid it separately.",
+                " and regrid it separately."
             )
             raise ValueError(msg)
 
diff --git a/src/xarray_regrid/utils.py b/src/xarray_regrid/utils.py
index 6979f84..0e4d2db 100644
--- a/src/xarray_regrid/utils.py
+++ b/src/xarray_regrid/utils.py
@@ -31,11 +31,10 @@ def __post_init__(self) -> None:
         msg = None
         if self.south > self.north:
             msg = (
-                "Value of north bound is greater than south bound."
+                "Value of south bound is greater than north bound."
                 "\nPlease check the bounds input."
             )
-            pass
-        if self.west > self.east:
+        elif self.west > self.east:
             msg = (
                 "Value of west bound is greater than east bound."
                 "\nPlease check the bounds input."
@@ -80,7 +79,7 @@ def create_lat_lon_coords(grid: Grid) -> tuple[np.ndarray, np.ndarray]:
             grid.south, grid.north + grid.resolution_lat, grid.resolution_lat
         )
 
-    if np.remainder((grid.east - grid.west), grid.resolution_lat) > 0:
+    if np.remainder((grid.east - grid.west), grid.resolution_lon) > 0:
         lon_coords = np.arange(grid.west, grid.east, grid.resolution_lon)
     else:
         lon_coords = np.arange(