coerce: floatify mixed int/float lists in attribute dicts

JSON parses whole numbers as int, but ifcopenshell's C++ binding
requires Python floats for AGGREGATE OF DOUBLE attributes such as
DirectionRatios and Coordinates. Convert list elements to float when
the list already contains at least one float, leaving pure-integer
lists (face indices etc.) unchanged.

Generated with the assistance of an AI coding tool.

src/ifcedit/ifcedit/coerce.py

@@ -92,7 +92,7 @@ def coerce_value(
 
     # dict types
     if origin is dict:
-        return json.loads(value_str)
+        return _floatify_numeric_lists(json.loads(value_str))
 
     # Simple types
     if type_hint is str:
@@ -148,6 +148,22 @@ def _coerce_entity_list(value_str: str, lookup_file: ifcopenshell.file | None) -
     return [_coerce_entity(item.strip(), lookup_file) for item in items]
 
 
+def _floatify_numeric_lists(obj):
+    """Recursively convert lists of numbers to lists of floats.
+
+    IFC C++ bindings require Python floats (not ints) for AGGREGATE OF DOUBLE
+    attributes (e.g. DirectionRatios, Coordinates). JSON parsing produces ints
+    for whole numbers like 0, which causes a TypeError at the binding level.
+    """
+    if isinstance(obj, dict):
+        return {k: _floatify_numeric_lists(v) for k, v in obj.items()}
+    if isinstance(obj, list) and obj and all(isinstance(v, (int, float)) for v in obj) and any(
+        isinstance(v, float) for v in obj
+    ):
+        return [float(v) for v in obj]
+    return obj
+
+
 def _split_list(value_str: str) -> list[str]:
     """Split a comma-separated string, handling JSON arrays too."""
     value_str = value_str.strip()

src/ifcedit/tests/test_coerce.py

@@ -83,6 +83,19 @@ class TestDictCoercion:
         result = coerce_value('{"IsExternal": true, "FireRating": "2HR"}', dict[str, object])
         assert result == {"IsExternal": True, "FireRating": "2HR"}
 
+    def test_mixed_float_int_list_coerced_to_float(self):
+        # [0.419, 0, 0.908] — JSON integer 0 mixed with floats must become float
+        # so ifcopenshell AGGREGATE OF DOUBLE attributes (e.g. DirectionRatios) don't reject the list
+        result = coerce_value('{"DirectionRatios": [0.419, 0, 0.908]}', dict[str, object])
+        assert result["DirectionRatios"] == pytest.approx([0.419, 0.0, 0.908])
+        assert all(isinstance(v, float) for v in result["DirectionRatios"])
+
+    def test_pure_int_list_not_coerced(self):
+        # All-integer lists (e.g. face indices) must stay as ints
+        result = coerce_value('{"CoordIndex": [0, 1, 2]}', dict[str, object])
+        assert result["CoordIndex"] == [0, 1, 2]
+        assert all(isinstance(v, int) for v in result["CoordIndex"])
+
 
 class TestListCoercion:
     def test_comma_separated(self):