Add more area slice caching tests

Author: djhoese

pyresample/future/geometry/_subset.py

@@ -2,11 +2,10 @@
 from __future__ import annotations
 
 import math
+from typing import TYPE_CHECKING, Any
 
 import numpy as np
 
-from pyresample import AreaDefinition
-
 # this caching module imports the geometries so this subset module
 # must be imported inside functions in the geometry modules if needed
 # to avoid circular dependencies
@@ -15,6 +14,9 @@
 from pyresample.geometry import get_geostationary_bounding_box_in_lonlats, logger
 from pyresample.utils import check_slice_orientation
 
+if TYPE_CHECKING:
+    from pyresample import AreaDefinition
+
 
 @cache_to_json_if("cache_geom_slices")
 def get_area_slices(
@@ -23,8 +25,10 @@ def get_area_slices(
         shape_divisible_by: int | None,
 ) -> tuple[slice, slice]:
     """Compute the slice to read based on an `area_to_cover`."""
-    if not isinstance(area_to_cover, AreaDefinition):
-        raise NotImplementedError('Only AreaDefinitions can be used')
+    if not _is_area_like(src_area):
+        raise NotImplementedError(f"Only AreaDefinitions are supported, not {type(src_area)}")
+    if not _is_area_like(area_to_cover):
+        raise NotImplementedError(f"Only AreaDefinitions are supported, not {type(area_to_cover)}")
 
     # Intersection only required for two different projections
     proj_def_to_cover = area_to_cover.crs
@@ -65,6 +69,10 @@ def get_area_slices(
             check_slice_orientation(y_slice))
 
 
+def _is_area_like(area_obj: Any) -> bool:
+    return hasattr(area_obj, "crs") and hasattr(area_obj, "area_extent")
+
+
 def _get_slice_starts_stops(src_area, area_to_cover):
     """Get x and y start and stop points for slicing."""
     llx, lly, urx, ury = area_to_cover.area_extent

pyresample/test/test_geometry/test_area.py

@@ -1823,7 +1823,8 @@ def test_area_to_cover_all_nan_bounds(self, geos_src_area, create_test_area):
         with pytest.raises(NotImplementedError):
             area_def.get_area_slices(area_to_cover)
 
-    def test_area_slices_caching(self, create_test_area, tmp_path):
+    @pytest.mark.parametrize("cache_slices", [False, True])
+    def test_area_slices_caching(self, create_test_area, tmp_path, cache_slices):
         """Check that area slices can be cached."""
         src_area = create_test_area(dict(proj="utm", zone=33),
                                     10980, 10980,
@@ -1832,21 +1833,49 @@ def test_area_slices_caching(self, create_test_area, tmp_path):
                                      100, 100,
                                      (15.9689, 58.5284, 16.4346, 58.6995))
         cache_glob = str(tmp_path / "geometry_slices_v1" / "*.json")
-        with pyresample.config.set(cache_dir=tmp_path, cache_geom_slices=False):
+        with pyresample.config.set(cache_dir=tmp_path, cache_geom_slices=cache_slices):
             assert len(glob(cache_glob)) == 0
             slice_x, slice_y = src_area.get_area_slices(crop_area)
-            assert len(glob(cache_glob)) == 0
-        with pyresample.config.set(cache_dir=tmp_path, cache_geom_slices=True):
-            assert len(glob(cache_glob)) == 0
-            slice_x, slice_y = src_area.get_area_slices(crop_area)
-            assert len(glob(cache_glob)) == 1
+            assert len(glob(cache_glob)) == int(cache_slices)
         assert slice_x == slice(5630, 8339)
         assert slice_y == slice(9261, 10980)
 
+        if cache_slices:
+            from pyresample.future.geometry._subset import get_area_slices
+            with pyresample.config.set(cache_dir=tmp_path):
+                get_area_slices.cache_clear()
+            assert len(glob(cache_glob)) == 0
+
+    def test_area_slices_caching_no_swaths(self, tmp_path, create_test_area, create_test_swath):
+        """Test that swath inputs produce a warning when tried to use in caching."""
+        from pyresample.future.geometry._subset import get_area_slices
+        from pyresample.test.utils import create_test_latitude, create_test_longitude
+        area = create_test_area(dict(proj="utm", zone=33),
+                                10980, 10980,
+                                (499980.0, 6490200.0, 609780.0, 6600000.0))
+        lons = create_test_longitude(-95.0, -75.0, shape=(1000, 500))
+        lats = create_test_latitude(25.0, 35.0, shape=(1000, 500))
+        swath = create_test_swath(lons, lats)
+
+        with pyresample.config.set(cache_dir=tmp_path, cache_geom_slices=True), pytest.raises(NotImplementedError):
+            with pytest.warns(UserWarning, match="unhashable"):
+                get_area_slices(swath, area, None)
+
+    @pytest.mark.parametrize("swath_as_src", [False, True])
+    def test_unsupported_slice_inputs(self, create_test_area, create_test_swath, swath_as_src):
+        """Test that swath inputs produce an error."""
         from pyresample.future.geometry._subset import get_area_slices
-        with pyresample.config.set(cache_dir=tmp_path):
-            get_area_slices.cache_clear()
-        assert len(glob(cache_glob)) == 0
+        from pyresample.test.utils import create_test_latitude, create_test_longitude
+        area = create_test_area(dict(proj="utm", zone=33),
+                                10980, 10980,
+                                (499980.0, 6490200.0, 609780.0, 6600000.0))
+        lons = create_test_longitude(-95.0, -75.0, shape=(1000, 500))
+        lats = create_test_latitude(25.0, 35.0, shape=(1000, 500))
+        swath = create_test_swath(lons, lats)
+
+        with pytest.raises(NotImplementedError):
+            args = (swath, area) if swath_as_src else (area, swath)
+            get_area_slices(*args, None)
 
 
 class TestBoundary: