Reject 0D/1D DataArray in to_geotiff with the clear "Expected 2D or 3D" ValueError

.claude/sweep-error-handling-state.csv

@@ -0,0 +1,2 @@
+module,last_inspected,issue,severity_max,categories_found,notes
+geotiff,2026-07-02,3604,MEDIUM,2;4,"to_geotiff 0D/1D DataArray raised opaque IndexError from _coords.py coords_to_transform (dims[-2]) instead of clean 'Expected 2D or 3D' ValueError; numpy path + 4D DataArray already clean. Fixed via early ndim guard before dispatch (eager/vrt/gpu) + 3 tests; PR #3604. Read-side param validation + typed-error hierarchy + allow_rotated/allow_invalid_nodata VRT+chunked opt-in threading verified clean (CUDA available, GPU paths run). gh issue create blocked by auto-mode; PR opened. Cat 2+4."

xrspatial/geotiff/_writers/eager.py

@@ -839,6 +839,19 @@ def _write_sidecars():
     _is_vrt_path = (
         isinstance(path, str) and path.lower().endswith('.vrt'))
 
+    # Reject arrays that are not 2D or 3D before any backend dispatch or
+    # georef resolution. ``.ndim`` is defined on DataArray, numpy, cupy,
+    # and dask inputs. Without this, a 0D/1D *DataArray* reaches
+    # ``coords_to_transform`` (which indexes ``dims[-2]``) and dies with an
+    # opaque ``IndexError: tuple index out of range`` pointing at
+    # ``_coords.py`` internals, while a 0D/1D numpy array or a 4D
+    # DataArray already gets the clear message below. Running the check
+    # here up front makes every backend (eager, VRT, GPU) reject the same
+    # bad shapes identically.
+    _ndim = getattr(data, 'ndim', None)
+    if _ndim is not None and _ndim not in (2, 3):
+        raise ValueError(f"Expected 2D or 3D array, got {_ndim}D")
+
     # Resolve GPU dispatch up front so the JPEG opt-in warning fires
     # exactly once. ``_write_geotiff_gpu`` emits its own warning on the
     # GPU path; emitting here as well would double-warn callers of

xrspatial/geotiff/tests/test_edge_cases.py

@@ -40,6 +40,26 @@ def test_0d_scalar(self, tmp_path):
         with pytest.raises(ValueError, match="Expected 2D"):
             to_geotiff(arr, str(tmp_path / 'bad.tif'))
 
+    def test_1d_dataarray(self, tmp_path):
+        # A 1D DataArray used to reach ``coords_to_transform`` (which
+        # indexes ``dims[-2]``) and raise an opaque ``IndexError: tuple
+        # index out of range`` instead of the clear message a 1D numpy
+        # array or a 4D DataArray already gets.
+        da = xr.DataArray(np.zeros(10, dtype=np.float32), dims=('x',))
+        with pytest.raises(ValueError, match="Expected 2D or 3D array, got 1D"):
+            to_geotiff(da, str(tmp_path / 'bad.tif'))
+
+    def test_0d_dataarray(self, tmp_path):
+        da = xr.DataArray(np.float32(42.0))
+        with pytest.raises(ValueError, match="Expected 2D or 3D array, got 0D"):
+            to_geotiff(da, str(tmp_path / 'bad.tif'))
+
+    def test_1d_dataarray_vrt(self, tmp_path):
+        # The ``.vrt`` write path shares the same pre-dispatch guard.
+        da = xr.DataArray(np.zeros(10, dtype=np.float32), dims=('x',))
+        with pytest.raises(ValueError, match="Expected 2D or 3D array, got 1D"):
+            to_geotiff(da, str(tmp_path / 'bad.vrt'))
+
     def test_unsupported_compression(self, tmp_path):
         arr = np.zeros((4, 4), dtype=np.float32)
         # ``to_geotiff`` validates ``compression`` up-front. The