Bonsai: batch array-duplicate + defensive guards

Replace N sequential duplicate_ifc_objects([parent]) calls in
_regenerate_array_body with one duplicate_ifc_object_n_times call
per layer, batching the fixed per-call overhead (snapshot gather,
UI refresh, decorator reload).

Guard batch_host_recut drain against dead StructRNA refs and prune
orphan array-child GUIDs at regen so outliner-delete of a
Bonsai-managed child cannot crash subsequent regenerate_array.

Recalculate walls after recreate_connections so Shift+D of
connected walls produces correct junction geometry without a
manual regen step.

Relates to #8088.

Generated with the assistance of an AI coding tool.

src/bonsai/test/bim/module/model/test_array_duplicate_batched.py

@@ -0,0 +1,376 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2026
+#
+# This file is part of Bonsai.
+#
+# Bonsai is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Bonsai is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was generated with the assistance of an AI coding tool.
+
+"""Tests for the batched array-duplicate path.
+
+`tool.Geometry.duplicate_ifc_object_n_times` lifts the per-call overhead of
+`duplicate_ifc_objects` (snapshot, UI refresh, decorator reload, select
+flips) out of the per-child loop in `_regenerate_array_body`. These tests
+pin three contracts:
+
+1. N-way batched duplicate produces N distinct entities mapped from the
+   source under `old_to_new[source_element]`, and the source object stays
+   selected throughout (no per-iteration deselect).
+2. Per-layer batching collapses the N independent UI refreshes into one.
+3. End-to-end array regen still yields the same number and shape of
+   children as the per-call baseline."""
+
+import json
+from unittest.mock import patch
+
+import bpy
+import ifcopenshell
+import pytest
+
+import bonsai.tool as tool
+from test.bim.bootstrap import NewFile
+
+pytestmark = pytest.mark.model
+
+
+def _build_actuator(name: str = "Actuator") -> tuple[bpy.types.Object, ifcopenshell.entity_instance]:
+    """Minimal IfcActuator + cube — matches the test_array_batch_recut.py shape."""
+    bpy.ops.bim.create_project()
+    bpy.ops.mesh.primitive_cube_add()
+    obj = bpy.context.active_object
+    obj.name = name
+    rprops = tool.Root.get_root_props()
+    rprops.ifc_product = "IfcElement"
+    bpy.ops.bim.assign_class(ifc_class="IfcActuator", predefined_type="ELECTRICACTUATOR", userdefined_type="")
+    element = tool.Ifc.get_entity(obj)
+    return obj, element
+
+
+def _build_actuator_with_array_pset(
+    count: int, x: float = 1.0
+) -> tuple[bpy.types.Object, ifcopenshell.entity_instance, list[dict]]:
+    obj, element = _build_actuator()
+    parent_data = [
+        {
+            "children": [],
+            "count": count,
+            "method": "OFFSET",
+            "x": x,
+            "y": 0.0,
+            "z": 0.0,
+            "use_local_space": False,
+            "sync_children": False,
+        }
+    ]
+    pset = ifcopenshell.api.pset.add_pset(tool.Ifc.get(), product=element, name="BBIM_Array")
+    ifcopenshell.api.pset.edit_pset(
+        tool.Ifc.get(),
+        pset=pset,
+        properties={"Data": json.dumps(parent_data), "Parent": element.GlobalId},
+    )
+    return obj, element, parent_data
+
+
+class TestDuplicateIfcObjectNTimes(NewFile):
+    def test_returns_empty_dict_for_zero_count(self):
+        obj, _ = _build_actuator()
+        result = tool.Geometry.duplicate_ifc_object_n_times(obj, 0)
+        assert result == {}
+
+    def test_returns_empty_dict_for_negative_count(self):
+        obj, _ = _build_actuator()
+        result = tool.Geometry.duplicate_ifc_object_n_times(obj, -3)
+        assert result == {}
+
+    def test_produces_n_distinct_entities(self):
+        obj, element = _build_actuator()
+        result = tool.Geometry.duplicate_ifc_object_n_times(obj, 5)
+        new_entities = result.get(element)
+        assert new_entities is not None
+        assert len(new_entities) == 5
+        assert len({e.id() for e in new_entities}) == 5
+        for new_entity in new_entities:
+            assert new_entity.is_a("IfcActuator")
+            assert new_entity.GlobalId != element.GlobalId
+
+    def test_source_stays_selected_after_batch(self):
+        obj, _ = _build_actuator()
+        obj.select_set(True)
+        tool.Geometry.duplicate_ifc_object_n_times(obj, 4)
+        assert obj in bpy.context.selected_objects, "source object must remain selected across batched duplicates"
+
+    def test_each_new_entity_has_blender_object(self):
+        obj, element = _build_actuator()
+        result = tool.Geometry.duplicate_ifc_object_n_times(obj, 3)
+        for new_entity in result[element]:
+            new_obj = tool.Ifc.get_object(new_entity)
+            assert new_obj is not None
+            assert new_obj is not obj
+
+
+class TestBatchedRefreshUIDataCallCount(NewFile):
+    def test_n_times_calls_refresh_ui_data_once(self):
+        obj, _ = _build_actuator()
+        with patch("bonsai.bim.handler.refresh_ui_data") as refresh_mock:
+            tool.Geometry.duplicate_ifc_object_n_times(obj, 8)
+        assert (
+            refresh_mock.call_count == 1
+        ), f"batched 8-way duplicate must call refresh_ui_data once, got {refresh_mock.call_count}"
+
+    def test_n_times_calls_reload_grid_decorator_once(self):
+        obj, _ = _build_actuator()
+        with patch.object(tool.Root, "reload_grid_decorator") as reload_mock:
+            tool.Geometry.duplicate_ifc_object_n_times(obj, 8)
+        assert reload_mock.call_count == 1
+
+
+class TestRegenerateArrayEndToEnd(NewFile):
+    def test_regenerate_array_creates_expected_children(self):
+        obj, element, parent_data = _build_actuator_with_array_pset(count=8)
+        bpy.context.view_layer.objects.active = obj
+        tool.Model.regenerate_array(obj, parent_data)
+
+        layer = parent_data[0]
+        assert len(layer["children"]) == 7, "8-element array means 7 new children (parent + 7)"
+        for child_guid in layer["children"]:
+            child_element = tool.Ifc.get().by_guid(child_guid)
+            assert child_element is not None
+            assert child_element.is_a("IfcActuator")
+            child_pset = ifcopenshell.util.element.get_pset(child_element, "BBIM_Array")
+            assert child_pset is not None
+            assert child_pset["Parent"] == element.GlobalId
+
+    def test_regenerate_array_parent_stays_selected(self):
+        obj, element, parent_data = _build_actuator_with_array_pset(count=4)
+        bpy.context.view_layer.objects.active = obj
+        obj.select_set(True)
+        tool.Model.regenerate_array(obj, parent_data)
+        assert (
+            obj in bpy.context.selected_objects
+        ), "regenerate_array must leave parent_obj selected on return (post-condition)"
+
+    def test_regen_operator_leaves_only_parent_selected_and_active(self):
+        """Post-condition parity between grow and shrink for the user-facing
+        ``bim.regenerate_array`` operator: only the parent is selected + active;
+        every child is deselected. Pre-fix the grow path left new children
+        selected, creating inconsistency with the shrink path.
+
+        Scoped to the operator, not the tool method — ``remove_array`` and
+        ``apply_array`` also invoke ``tool.Model.regenerate_array`` internally
+        but expect a different post-selection state (children stay selected
+        for user follow-up work)."""
+        obj, element, parent_data = _build_actuator_with_array_pset(count=6)
+        bpy.context.view_layer.objects.active = obj
+        obj.select_set(True)
+        bpy.ops.bim.regenerate_array()
+
+        assert obj in bpy.context.selected_objects
+        assert bpy.context.view_layer.objects.active is obj
+        parent_pset = ifcopenshell.util.element.get_pset(element, "BBIM_Array")
+        parent_data_after = json.loads(parent_pset["Data"])
+        for child_guid in parent_data_after[0]["children"]:
+            child_element = tool.Ifc.get().by_guid(child_guid)
+            child_obj = tool.Ifc.get_object(child_element)
+            assert (
+                child_obj not in bpy.context.selected_objects
+            ), f"child {child_obj.name} must be deselected on regenerate_array return"
+
+    def test_regen_operator_after_shrink_still_leaves_only_parent_selected(self):
+        obj, element, parent_data = _build_actuator_with_array_pset(count=6)
+        bpy.context.view_layer.objects.active = obj
+        bpy.ops.bim.regenerate_array()
+
+        parent_pset = ifcopenshell.util.element.get_pset(element, "BBIM_Array")
+        arrays = json.loads(parent_pset["Data"])
+        arrays[0]["count"] = 3
+        pset_entity = tool.Ifc.get().by_id(parent_pset["id"])
+        ifcopenshell.api.pset.edit_pset(tool.Ifc.get(), pset=pset_entity, properties={"Data": json.dumps(arrays)})
+        bpy.ops.bim.regenerate_array()
+
+        assert obj in bpy.context.selected_objects
+        assert bpy.context.view_layer.objects.active is obj
+        parent_pset = ifcopenshell.util.element.get_pset(element, "BBIM_Array")
+        arrays_after = json.loads(parent_pset["Data"])
+        for child_guid in arrays_after[0]["children"]:
+            child_element = tool.Ifc.get().by_guid(child_guid)
+            child_obj = tool.Ifc.get_object(child_element)
+            assert child_obj not in bpy.context.selected_objects
+
+    def test_regenerate_array_child_positions_match_offset(self):
+        obj, element, parent_data = _build_actuator_with_array_pset(count=4, x=2.5)
+        bpy.context.view_layer.objects.active = obj
+        parent_x = obj.matrix_world.translation.x
+        tool.Model.regenerate_array(obj, parent_data)
+
+        layer = parent_data[0]
+        for i, child_guid in enumerate(layer["children"], start=1):
+            child_element = tool.Ifc.get().by_guid(child_guid)
+            child_obj = tool.Ifc.get_object(child_element)
+            expected_x = parent_x + 2.5 * i
+            assert child_obj.matrix_world.translation.x == pytest.approx(
+                expected_x
+            ), f"child {i}: expected x≈{expected_x}, got {child_obj.matrix_world.translation.x}"
+
+
+class TestRegenerateArrayUIRefreshCoalesces(NewFile):
+    def test_n_children_grow_calls_refresh_ui_data_once_per_layer(self):
+        obj, element, parent_data = _build_actuator_with_array_pset(count=8)
+        bpy.context.view_layer.objects.active = obj
+        with patch("bonsai.bim.handler.refresh_ui_data") as refresh_mock:
+            tool.Model.regenerate_array(obj, parent_data)
+        assert refresh_mock.call_count == 1, (
+            "growing an array layer from 0 to 7 children must call refresh_ui_data once, "
+            f"got {refresh_mock.call_count}"
+        )
+
+    def test_n_children_grow_calls_reload_grid_decorator_once_per_layer(self):
+        obj, element, parent_data = _build_actuator_with_array_pset(count=8)
+        bpy.context.view_layer.objects.active = obj
+        with patch.object(tool.Root, "reload_grid_decorator") as reload_mock:
+            tool.Model.regenerate_array(obj, parent_data)
+        assert reload_mock.call_count == 1
+
+
+class TestRecalculateWallsWithNewConnections(NewFile):
+    """Pins the post-connection wall recalc: after ``recreate_connections``
+    wires new IfcRelConnectsPathElements onto duplicated walls, the wall
+    bodies must be re-recalculated because the in-loop ``regenerate_wall``
+    fired before the connections existed. Otherwise the junction geometry
+    stays stale and the user has to manually regen."""
+
+    def test_walls_with_new_connections_are_recalculated(self):
+        from unittest.mock import Mock
+
+        wall_new = Mock()
+        wall_new.is_a = lambda c: c == "IfcWall"
+        wall_new.ConnectedTo = [Mock()]
+        wall_new.ConnectedFrom = []
+
+        wall_obj = Mock()
+        old_to_new = {Mock(): [wall_new]}
+
+        with patch.object(tool.Ifc, "get_object", return_value=wall_obj), patch.object(
+            tool.Model, "recalculate_walls"
+        ) as recalc_mock:
+            tool.Geometry._recalculate_walls_with_new_connections(old_to_new)
+
+        assert recalc_mock.call_count == 1
+        assert recalc_mock.call_args.args[0] == [wall_obj]
+
+    def test_walls_without_connections_are_skipped(self):
+        from unittest.mock import Mock
+
+        wall_new = Mock()
+        wall_new.is_a = lambda c: c == "IfcWall"
+        wall_new.ConnectedTo = []
+        wall_new.ConnectedFrom = []
+
+        old_to_new = {Mock(): [wall_new]}
+
+        with patch.object(tool.Ifc, "get_object", return_value=Mock()), patch.object(
+            tool.Model, "recalculate_walls"
+        ) as recalc_mock:
+            tool.Geometry._recalculate_walls_with_new_connections(old_to_new)
+
+        assert recalc_mock.call_count == 0, "walls with no new connections must not trigger a recalc pass"
+
+    def test_non_wall_entities_are_skipped(self):
+        from unittest.mock import Mock
+
+        actuator_new = Mock()
+        actuator_new.is_a = lambda c: c == "IfcActuator"
+        actuator_new.ConnectedTo = [Mock()]
+
+        old_to_new = {Mock(): [actuator_new]}
+
+        with patch.object(tool.Ifc, "get_object", return_value=Mock()), patch.object(
+            tool.Model, "recalculate_walls"
+        ) as recalc_mock:
+            tool.Geometry._recalculate_walls_with_new_connections(old_to_new)
+
+        assert recalc_mock.call_count == 0
+
+    def test_multiple_new_walls_collected_into_one_call(self):
+        from unittest.mock import Mock
+
+        wall_a_new = Mock()
+        wall_a_new.is_a = lambda c: c == "IfcWall"
+        wall_a_new.ConnectedTo = [Mock()]
+        wall_a_new.ConnectedFrom = []
+        wall_b_new = Mock()
+        wall_b_new.is_a = lambda c: c == "IfcWall"
+        wall_b_new.ConnectedTo = []
+        wall_b_new.ConnectedFrom = [Mock()]
+
+        objs = {wall_a_new: Mock(), wall_b_new: Mock()}
+        old_to_new = {Mock(): [wall_a_new], Mock(): [wall_b_new]}
+
+        with patch.object(tool.Ifc, "get_object", side_effect=lambda e: objs.get(e)), patch.object(
+            tool.Model, "recalculate_walls"
+        ) as recalc_mock:
+            tool.Geometry._recalculate_walls_with_new_connections(old_to_new)
+
+        assert recalc_mock.call_count == 1
+        assert set(recalc_mock.call_args.args[0]) == {objs[wall_a_new], objs[wall_b_new]}
+
+
+class TestOrphanArrayChildPrune(NewFile):
+    """Outliner / keyboard delete of a Bonsai-managed array child bypasses
+    ``bim.delete``'s cascade, leaving the IFC entity and its opening / filling
+    refs behind. Regen must prune these orphans before the main loop or the
+    stale registry entry corrupts the ``batch_host_recut`` drain."""
+
+    def test_orphan_ifc_entity_pruned_from_children_list(self):
+        obj, element, parent_data = _build_actuator_with_array_pset(count=4)
+        bpy.context.view_layer.objects.active = obj
+        tool.Model.regenerate_array(obj, parent_data)
+        assert len(parent_data[0]["children"]) == 3
+
+        orphan_guid = parent_data[0]["children"][1]
+        orphan_element = tool.Ifc.get().by_guid(orphan_guid)
+        orphan_obj = tool.Ifc.get_object(orphan_element)
+        assert orphan_obj is not None
+        bpy.data.objects.remove(orphan_obj, do_unlink=True)
+
+        tool.Model.regenerate_array(obj, parent_data)
+
+        assert (
+            orphan_guid not in parent_data[0]["children"]
+        ), "orphan GUID must be pruned from array['children'] once its Blender object is dead"
+        try:
+            still_there = tool.Ifc.get().by_guid(orphan_guid)
+        except RuntimeError:
+            still_there = None
+        assert still_there is None, "orphan IFC entity must be cascade-removed, not left as a leak"
+
+    def test_regen_completes_when_child_deleted_outside_bim_cascade(self):
+        obj, element, parent_data = _build_actuator_with_array_pset(count=6)
+        bpy.context.view_layer.objects.active = obj
+        tool.Model.regenerate_array(obj, parent_data)
+
+        victim_guid = parent_data[0]["children"][2]
+        victim_element = tool.Ifc.get().by_guid(victim_guid)
+        victim_obj = tool.Ifc.get_object(victim_element)
+        bpy.data.objects.remove(victim_obj, do_unlink=True)
+
+        tool.Model.regenerate_array(obj, parent_data)
+
+        assert len(parent_data[0]["children"]) == 5, "regen must rebuild to the target count after pruning the orphan"
+        for guid in parent_data[0]["children"]:
+            child = tool.Ifc.get().by_guid(guid)
+            child_obj = tool.Ifc.get_object(child)
+            assert child_obj is not None, "every surviving child must have a live Blender object"
+
+

src/bonsai/test/tool/test_geometry_batch_host_recut.py

@@ -164,6 +164,62 @@ def test_stale_element_skipped_at_drain():
     assert recut.call_count == 0
 
 
+class _DeadStructRNA:
+    """Simulates a Blender object whose StructRNA has been removed — every
+    attribute access raises ReferenceError. Enqueue this as voided_obj to
+    reproduce the outliner-mid-batch-delete crash."""
+
+    def __getattr__(self, name):
+        raise ReferenceError("StructRNA of type Object has been removed")
+
+    def __bool__(self):
+        raise ReferenceError("StructRNA of type Object has been removed")
+
+
+def test_dead_structrna_recut_skipped_at_drain():
+    """Blender object is deleted while the batch is open (outliner delete +
+    manual DEL bypass the bim.delete cascade). The drain must skip it silently
+    — not raise — so unrelated hosts in the same batch still get their recut."""
+    from bonsai import tool
+
+    dead_obj = _DeadStructRNA()
+    live_obj = _mock_voided_obj("LiveWall")
+    rep = Mock()
+
+    def get_entity(obj):
+        # Called only when the guard clears — for the dead ref, guard short-circuits first.
+        return _mock_element(2)
+
+    with patch("bonsai.core.geometry.switch_representation") as recut, patch.object(
+        tool.Ifc, "get_entity", side_effect=get_entity
+    ), patch.object(tool.Geometry, "get_active_representation", return_value=rep):
+        with tool.Geometry.batch_host_recut():
+            tool.Geometry._host_recut_queue[999] = (dead_obj, rep)
+            tool.Geometry.recut_host(live_obj, rep)
+
+    assert recut.call_count == 1, "live host must still get its recut despite a dead sibling in the queue"
+    drained_obj = recut.call_args.kwargs["obj"]
+    assert drained_obj is live_obj
+
+
+def test_dead_structrna_update_skipped_at_drain():
+    """Same guarantee for update_representation drain path."""
+    from bonsai import tool
+
+    dead_obj = _DeadStructRNA()
+    live_obj = _mock_voided_obj("LiveWall")
+    bpy_ops_mock = Mock()
+
+    with patch("bonsai.tool.geometry.bpy.ops", new=bpy_ops_mock), patch.object(
+        tool.Ifc, "get_entity", return_value=_mock_element(42)
+    ), patch.object(tool.Geometry, "get_active_representation", return_value=Mock()):
+        with tool.Geometry.batch_host_recut():
+            tool.Geometry._host_update_queue[999] = dead_obj
+            tool.Geometry.update_host_representation(live_obj)
+
+    assert bpy_ops_mock.bim.update_representation.call_count == 1
+
+
 def test_exception_inside_batch_still_resets_state():
     from bonsai import tool