Allow Polygon geometry for Basin / Area. (#1875)

Fixes #1850

python/ribasim/ribasim/geometry/area.py

@@ -2,7 +2,7 @@
 from pandera.dtypes import Int32
 from pandera.typing import Index, Series
 from pandera.typing.geopandas import GeoSeries
-from shapely.geometry import MultiPolygon
+from shapely.geometry import MultiPolygon, Polygon
 
 from .base import _GeoBaseSchema
 
@@ -11,3 +11,9 @@ class BasinAreaSchema(_GeoBaseSchema):
     fid: Index[Int32] = pa.Field(default=0, check_name=True)
     node_id: Series[Int32] = pa.Field(nullable=False, default=0)
     geometry: GeoSeries[MultiPolygon] = pa.Field(default=None, nullable=True)
+
+    @pa.parser("geometry")
+    def convert_to_multi(cls, series):
+        return series.apply(
+            lambda geom: MultiPolygon([geom]) if isinstance(geom, Polygon) else geom
+        )

python/ribasim/tests/test_validation.py

@@ -11,7 +11,7 @@
     pid_control,
     pump,
 )
-from shapely import Point
+from shapely import MultiPolygon, Point, Polygon
 
 
 def test_duplicate_edge(basic):
@@ -171,3 +171,18 @@ def test_minimum_control_neighbor():
             ],
         )
         model.write("test.toml")
+
+
+def test_geometry_validation():
+    point = Point(0.0, 0.0)
+    poly = point.buffer(1.0)
+
+    assert isinstance(poly, Polygon)
+    basinarea = basin.Area(geometry=[poly])
+    assert isinstance(basinarea.df.geometry[0], MultiPolygon)
+
+    basinarea = basin.Area(geometry=[basinarea.df.geometry[0]])
+    assert isinstance(basinarea.df.geometry[0], MultiPolygon)
+
+    with pytest.raises(ValueError):
+        basin.Area(geometry=[point])