added covarage

api/app/core/viewshed.py

@@ -16,8 +16,9 @@ from rasterio.warp import (
     reproject,
     transform,
 )
+from pyproj import Transformer
 from shapely.geometry import mapping, shape
-from shapely.ops import unary_union
+from shapely.ops import transform as shapely_transform, unary_union
 
 from app.core.dem import _dem_files, _sample_dataset
 from app.core.geo import GeoPoint
@@ -122,6 +123,16 @@ def _run_gdal_viewshed(
     subprocess.run(command, check=True, capture_output=True, text=True)
 
 
+def _to_wgs84(geom, src_crs: CRS | None):
+    if src_crs is None:
+        return geom
+    crs_text = src_crs.to_string()
+    if crs_text in {"EPSG:4326", "OGC:CRS84", "WGS84"}:
+        return geom
+    transformer = Transformer.from_crs(src_crs, "EPSG:4326", always_xy=True)
+    return shapely_transform(transformer.transform, geom)
+
+
 def _viewshed_geojson(viewshed_path: Path, observer: GeoPoint) -> dict[str, Any]:
     features: list[dict[str, Any]] = []
     with rasterio.open(viewshed_path) as dataset:
@@ -130,7 +141,7 @@ def _viewshed_geojson(viewshed_path: Path, observer: GeoPoint) -> dict[str, Any]
         for geom, value in shapes(mask, mask=mask.astype(bool), transform=dataset.transform):
             if int(value) != 1:
                 continue
-            polygon = shape(geom)
+            polygon = _to_wgs84(shape(geom), dataset.crs)
             if polygon.is_empty:
                 continue
             features.append(