ty: detect unresolved references

src/ifcopenshell-python/ifcopenshell/api/alignment/_add_segment_to_curve.py

@@ -159,8 +159,10 @@ def _add_segment_to_curve(
     else:
         assert False
 
+    end_point = ...
     for mapped_segment in mapped_segments:
         if mapped_segment:
             end_point = _add_curve_segment_to_composite_curve(file, layout_segment, mapped_segment, curve)
 
+    assert end_point is not ...
     return end_point

src/ifcopenshell-python/ifcopenshell/api/alignment/_get_segment_start_point_label.py

@@ -308,5 +308,7 @@ def _get_segment_start_point_label(prev_segment: entity_instance, segment: entit
             label = _cant_callback(prev_segment, segment)
         else:
             label = _cant_label(prev_segment, segment)
+    else:
+        assert False, s.DesignParameters
 
     return label

src/ifcopenshell-python/ifcopenshell/api/alignment/create_as_polyline.py

@@ -46,6 +46,7 @@ def _create_layout(file: ifcopenshell.file, alignment: entity_instance, points:
     ifcopenshell.api.nest.assign_object(file, related_objects=alignment_layouts, relating_object=alignment)
 
     start_dist_along = 0.0
+    gradient = None
     for p1, p2 in zip(points, points[1:]):
         x1, y1, z1 = p1.Coordinates
         x2, y2, z2 = p2.Coordinates
@@ -100,6 +101,7 @@ def _create_layout(file: ifcopenshell.file, alignment: entity_instance, points:
     ifcopenshell.api.nest.assign_object(file, related_objects=[hsegment], relating_object=alignment_layouts[0])
 
     if include_vertical:
+        assert gradient is not None
         vsegment = file.createIfcAlignmentSegment(
             ifcopenshell.guid.new(),
             DesignParameters=file.createIfcAlignmentVerticalSegment(

src/ifcopenshell-python/ifcopenshell/api/alignment/create_from_csv.py

@@ -57,6 +57,7 @@ def create_from_csv(file: ifcopenshell.file, filepath: str) -> entity_instance:
     :param filepath: path the to CSV file
     :return: IfcAlignment
     """
+    alignment = None
     with open(filepath, newline="") as csvfile:
         reader = csv.reader(csvfile)
         row_count = 0
@@ -89,9 +90,14 @@ def create_from_csv(file: ifcopenshell.file, filepath: str) -> entity_instance:
                 )
             else:
                 # add all subsequent vertical alignments
+                assert alignment is not None
                 vertical_layout = ifcopenshell.api.alignment.add_vertical_layout(file, alignment)
                 ifcopenshell.api.alignment.layout_vertical_alignment_by_pi_method(
                     file, vertical_layout, coordinates, radii
                 )
 
+    if row_count == 0:
+        raise ValueError(f"CSV file '{filepath}' is empty; expected at least one row for the horizontal alignment.")
+
+    assert alignment is not None
     return alignment