Fix bug where removing an element in an aggregation could leave the file in an invalid state

src/ifcopenshell-python/ifcopenshell/api/root/remove_product.py

@@ -64,4 +64,9 @@ class Usecase:
                             ifcopenshell.api.run("root.remove_product", self.file, product=subelement)
                     if not inverse.RelatedObjects:
                         self.file.remove(inverse)
+            elif inverse.is_a("IfcRelAggregates"):
+                if inverse.RelatingObject == self.settings["product"]:
+                    self.file.remove(inverse)
+                elif len(inverse.RelatedObjects) == 1:
+                    self.file.remove(inverse)
         self.file.remove(self.settings["product"])

src/ifcopenshell-python/test/api/root/test_remove_product.py

@@ -140,3 +140,25 @@ class TestRemoveProduct(test.bootstrap.IFC4):
         assert len(self.file.by_type("IfcChiller")) == 0
         assert len(self.file.by_type("IfcRelNests")) == 0
         assert len(self.file.by_type("IfcDistributionPort")) == 0
+
+    def test_removing_all_aggregate_relationships_of_a_whole(self):
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcElementAssembly")
+        subelement = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcBeam")
+        ifcopenshell.api.run("aggregate.assign_object", self.file, product=subelement, relating_object=element)
+        total_entities = len(list(self.file))
+        ifcopenshell.api.run("root.remove_product", self.file, product=element)
+        assert len(list(self.file)) == total_entities - 2
+        assert len(self.file.by_type("IfcRelAggregates")) == 0
+        assert len(self.file.by_type("IfcElementAssembly")) == 0
+        assert len(self.file.by_type("IfcBeam")) == 1
+
+    def test_removing_all_aggregate_relationships_of_a_part(self):
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcElementAssembly")
+        subelement = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcBeam")
+        ifcopenshell.api.run("aggregate.assign_object", self.file, product=subelement, relating_object=element)
+        total_entities = len(list(self.file))
+        ifcopenshell.api.run("root.remove_product", self.file, product=subelement)
+        assert len(list(self.file)) == total_entities - 2
+        assert len(self.file.by_type("IfcRelAggregates")) == 0
+        assert len(self.file.by_type("IfcElementAssembly")) == 1
+        assert len(self.file.by_type("IfcBeam")) == 0