Updates update_key_point_referents to confirm to CT 4.1.4.4.3

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

@@ -32,21 +32,6 @@ from ifcopenshell.api.alignment._sort_nest import _sort_nest
 from ifcopenshell.api.alignment.update_fallback_position import update_fallback_position
 
 
-def _get_key_point_referent_nest(layout: entity_instance) -> Optional[entity_instance]:
-    """
-    Searches layout.IsNestedBy for the IfcRelNests whose RelatedObjects are IfcReferent.
-
-    This is distinct from both get_stationing_nest (scoped to the parent IfcAlignment, and
-    specifically the STATION/station-equation nest) and get_alignment_segment_nest (the *segment*
-    nest that also lives on layout.IsNestedBy, holding IfcAlignmentSegment, never IfcReferent).
-    """
-    for nest in layout.IsNestedBy:
-        for related_object in nest.RelatedObjects:
-            if related_object.is_a("IfcReferent"):
-                return nest
-    return None
-
-
 def _remove_referent(file: ifcopenshell.file, referent: entity_instance) -> None:
     """Cleanly deletes a key-point IfcReferent: its Pset_Stationing, its ObjectPlacement (if
     exclusively owned by it), and finally the referent itself."""
@@ -129,9 +114,11 @@ def update_key_point_referents(
     get_stationing_nest) -- key-point referents never belong in either of those.
 
     :param layout: IfcAlignmentHorizontal, IfcAlignmentVertical, or IfcAlignmentCant
-    :param rel_nests: an existing IfcRelNests to (re)populate. May live anywhere (e.g. the parent
+    :param rel_nests: an existing IfcRelNests to (re)populate; its RelatingObject must be the
-        IfcAlignment, the layout, or elsewhere) -- the caller decides. If omitted, an existing
+        IfcAlignment that nests `layout` (TypeError is raised otherwise). If omitted, a new
-        referent-nest already on `layout` is reused, or a new one is created and related to `layout`.
+        IfcRelNests is always created and related to that IfcAlignment -- there is no implicit
+        search for or reuse of a previously created nest. Callers who want to regenerate into an
+        existing nest must pass it back in explicitly via `rel_nests`.
     :param clear: if True, deletes all IfcReferent currently in rel_nests.RelatedObjects (and their
         Pset_Stationing) before regenerating. If False (default), new referents are appended to
         whatever already exists -- no deduplication.
@@ -167,12 +154,20 @@ def update_key_point_referents(
             f"Expected entity type to be one of {[_ for _ in expected_types]}, instead received {layout.is_a()}"
         )
 
-    if rel_nests is None:
+    alignment = ifcopenshell.api.alignment.get_alignment(layout)
-        rel_nests = _get_key_point_referent_nest(layout)
+    if alignment is None:
-        if rel_nests is None:
+        raise ValueError(f"{layout.is_a()} #{layout.id()} is not nested under an IfcAlignment.")
-            rel_nests = file.createIfcRelNests(
+
-                GlobalId=ifcopenshell.guid.new(), RelatingObject=layout, RelatedObjects=()
+    if rel_nests is not None:
+        if not rel_nests.RelatingObject.is_a("IfcAlignment"):
+            raise TypeError(
+                f"Expected rel_nests.RelatingObject to be IfcAlignment, instead received "
+                f"{rel_nests.RelatingObject.is_a()}"
             )
+    else:
+        rel_nests = file.createIfcRelNests(
+            GlobalId=ifcopenshell.guid.new(), RelatingObject=alignment, RelatedObjects=()
+        )
 
     if clear:
         for referent in list(rel_nests.RelatedObjects):
@@ -189,7 +184,6 @@ def update_key_point_referents(
         )
         return rel_nests
 
-    alignment = ifcopenshell.api.alignment.get_alignment(layout)
     start_station = ifcopenshell.api.alignment.get_alignment_start_station(file, alignment)
     curve = ifcopenshell.api.alignment.get_layout_curve(layout)
     is_horizontal = layout.is_a("IfcAlignmentHorizontal")

src/ifcopenshell-python/test/api/alignment/test_update_key_point_referents.py

@@ -82,13 +82,13 @@ def test_default_rel_nests_created_when_none_provided():
     nest = ifcopenshell.api.alignment.update_key_point_referents(file, horizontal)
 
     assert nest.is_a("IfcRelNests")
-    assert nest.RelatingObject == horizontal
+    assert nest.RelatingObject == alignment
     assert nest.id() != segment_nest.id()
     assert len(nest.RelatedObjects) == 8
     assert all(r.is_a("IfcReferent") for r in nest.RelatedObjects)
 
 
-def test_second_call_without_rel_nests_reuses_existing_nest():
+def test_second_call_without_rel_nests_creates_separate_nest():
     file = _new_file()
     alignment = _build_alignment(file)
     horizontal = ifcopenshell.api.alignment.get_horizontal_layout(alignment)
@@ -97,18 +97,31 @@ def test_second_call_without_rel_nests_reuses_existing_nest():
     nest1 = ifcopenshell.api.alignment.update_key_point_referents(file, horizontal)
     nest2 = ifcopenshell.api.alignment.update_key_point_referents(file, horizontal)
 
-    assert nest1.id() == nest2.id()
+    assert nest1.id() != nest2.id()
-    assert len(nest2.RelatedObjects) == 16
+    assert len(nest1.RelatedObjects) == 8
+    assert len(nest2.RelatedObjects) == 8
     segment_count_after = len(ifcopenshell.api.alignment.get_alignment_segment_nest(horizontal).RelatedObjects)
     assert segment_count_after == segment_count_before
 
 
+def test_passing_previous_nest_back_in_accumulates():
+    file = _new_file()
+    alignment = _build_alignment(file)
+    horizontal = ifcopenshell.api.alignment.get_horizontal_layout(alignment)
+
+    nest1 = ifcopenshell.api.alignment.update_key_point_referents(file, horizontal)
+    nest2 = ifcopenshell.api.alignment.update_key_point_referents(file, horizontal, rel_nests=nest1)
+
+    assert nest1.id() == nest2.id()
+    assert len(nest2.RelatedObjects) == 16
+
+
 def test_provided_rel_nests_is_used_as_is():
     file = _new_file()
     alignment = _build_alignment(file)
     horizontal = ifcopenshell.api.alignment.get_horizontal_layout(alignment)
 
-    # the nest may live anywhere the caller chooses, e.g. hung off the parent IfcAlignment
+    # rel_nests.RelatingObject must be the IfcAlignment that nests `layout`
     rel_nests = file.createIfcRelNests(GlobalId=ifcopenshell.guid.new(), RelatingObject=alignment, RelatedObjects=())
 
     result = ifcopenshell.api.alignment.update_key_point_referents(file, horizontal, rel_nests=rel_nests)
@@ -118,6 +131,17 @@ def test_provided_rel_nests_is_used_as_is():
     assert len(result.RelatedObjects) == 8
 
 
+def test_provided_rel_nests_with_wrong_relating_object_raises_type_error():
+    file = _new_file()
+    alignment = _build_alignment(file)
+    horizontal = ifcopenshell.api.alignment.get_horizontal_layout(alignment)
+
+    rel_nests = file.createIfcRelNests(GlobalId=ifcopenshell.guid.new(), RelatingObject=horizontal, RelatedObjects=())
+
+    with pytest.raises(TypeError):
+        ifcopenshell.api.alignment.update_key_point_referents(file, horizontal, rel_nests=rel_nests)
+
+
 def test_clear_true_removes_old_referents_and_psets():
     file = _new_file()
     alignment = _build_alignment(file)
@@ -356,8 +380,10 @@ def test_returns_ifc_rel_nests():
 
 test_wrong_layout_type_raises_type_error()
 test_default_rel_nests_created_when_none_provided()
-test_second_call_without_rel_nests_reuses_existing_nest()
+test_second_call_without_rel_nests_creates_separate_nest()
+test_passing_previous_nest_back_in_accumulates()
 test_provided_rel_nests_is_used_as_is()
+test_provided_rel_nests_with_wrong_relating_object_raises_type_error()
 test_clear_true_removes_old_referents_and_psets()
 test_clear_false_appends_without_dedup()
 test_default_horizontal_labels_and_order()