Add test for diagonal coverage with cover_scale (#679)

* Add test for diagonal coverage

* Use round to have better control on decimals

* Use finer cover_scale

* lint

---------

Co-authored-by: vincentsarago <vincent.sarago@gmail.com>

tests/test_models.py

@@ -460,6 +460,7 @@ def test_imagedata_coverage():
     coverage = im.get_coverage_array({"type": "Feature", "geometry": poly})
     assert numpy.unique(coverage).tolist() == [0.25]
 
+    # non-default CRS
     poly = {
         "type": "Polygon",
         "coordinates": [
@@ -480,3 +481,17 @@ def test_imagedata_coverage():
         {"type": "Feature", "geometry": poly}, shape_crs="epsg:3857"
     )
     assert numpy.unique(coverage).tolist() == [0.25]
+
+    # polygon with diagonal cut - requires higher cover_scale
+    im = ImageData(
+        numpy.ma.array((1, 2, 3, 4)).reshape((1, 2, 2)),
+        crs="epsg:4326",
+        bounds=(-180, -90, 180, 90),
+    )
+    poly = {
+        "type": "Polygon",
+        "coordinates": [[[-90.0, -45.0], [90.0, -45.0], [-90.0, 45.0], [-90.0, -45.0]]],
+    }
+
+    coverage = im.get_coverage_array(poly, cover_scale=1000)
+    assert numpy.round(numpy.unique(coverage), decimals=3).tolist() == [0, 0.125, 0.25]