Fix: Issue with arrange() import of networkx (#101)

* run test set without networkx

* fix macos name

* fix networkx removal

* tests + fix for networkx missing

* udpate changelog and version number

* test for grid_positions

Author: BradyAJohnston

.github/workflows/tests.yml

@@ -7,7 +7,7 @@ on:
     branches: ["*"]
 
 jobs:
-  build:
+  test:
     runs-on: ${{ matrix.os }}
     strategy:
       max-parallel: 4

docs/changelog.qmd

@@ -1,6 +1,13 @@
 ---
 title: Changelog
 ---
+
+## v520.0.1 - 2026-06-05
+
+### Enhancements
+### Fixes
+ - Import and usage of the `arrange()` function properly handles the optional `netowrkx` dependency
+
 ## v520.0.0 - 2026-06-04
 
 ### Enhancements

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "nodebpy"
-version = "520.0.0"
+version = "520.0.1"
 description = "Build nodes trees in Blender more elegantly with code"
 readme = "README.md"
 authors = [

src/nodebpy/lib/nodearrange/arrange/__init__.py

@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0-or-later

tests/__snapshots__/test_usecases.ambr

@@ -68,6 +68,31 @@
   ```
   '''
 # ---
+# name: test_active_grid_positions
+  '''
+  ```{mermaid}
+  graph LR
+      N0("Group Input"):::default-node
+      N1("Grid to Points"):::geometry-node
+      N2("Combine XYZ"):::converter-node
+      N3("Store Named Attribute"):::default-node
+      N4("Store Named Attribute"):::default-node
+      N5("Delete Geometry"):::geometry-node
+      N6("Group Output"):::default-node
+      N0 -->|"Grid->Grid"| N1
+      N1 -->|"X->X"| N2
+      N1 -->|"Y->Y"| N2
+      N1 -->|"Z->Z"| N2
+      N2 -->|"Vector->Value"| N3
+      N1 -->|"Points->Geometry"| N3
+      N1 -->|"Value->Value"| N4
+      N3 -->|"Geometry->Geometry"| N4
+      N1 -->|"Is Tile->Selection"| N5
+      N4 -->|"Geometry->Geometry"| N5
+      N5 -->|"Geometry->Points"| N6
+  ```
+  '''
+# ---
 # name: test_bundle_path_filter
   '''
   ```{mermaid}

tests/test_arrange_no_networkx.py

@@ -0,0 +1,68 @@
+"""Regression tests for building node trees when networkx is unavailable.
+
+When nodebpy is vendored into a Blender extension, the optional ``networkx``
+dependency is frequently absent. The Sugiyama layout should then fall back to
+the simple arrangement instead of crashing.
+
+The subtle failure mode this guards against is order-dependent: the *first*
+arrange attempt raises a clean ``ImportError`` (which is caught and falls back),
+but a *second* attempt used to surface a raw ``KeyError`` from the namespace
+package machinery, escaping the ``except ImportError`` guard. So we must build
+more than one tree in the same process to exercise the real bug.
+"""
+
+import sys
+
+import pytest
+
+from nodebpy import TreeBuilder
+from nodebpy import geometry as g
+
+
+@pytest.fixture
+def no_networkx():
+    """Simulate a vendored install where networkx cannot be imported.
+
+    Setting ``sys.modules['networkx'] = None`` makes ``import networkx`` raise
+    ``ImportError``. We also evict the cached ``nodebpy.lib.nodearrange``
+    modules so the import is genuinely re-attempted (rebuilding the namespace
+    package path), matching the user's fresh-process scenario.
+    """
+    blocked = "networkx"
+    saved = {
+        k: v
+        for k, v in sys.modules.items()
+        if k == blocked
+        or k.startswith(blocked + ".")
+        or k.startswith("nodebpy.lib.nodearrange")
+    }
+    for key in saved:
+        del sys.modules[key]
+    sys.modules[blocked] = None  # force ImportError on `import networkx`
+    try:
+        yield
+    finally:
+        del sys.modules[blocked]
+        sys.modules.update(saved)
+
+
+def _build(name: str) -> TreeBuilder:
+    with TreeBuilder.geometry(name) as tree:  # default arrange="sugiyama"
+        geo = tree.inputs.geometry()
+        out = tree.outputs.geometry()
+        _ = geo >> g.SetPosition() >> g.RealizeInstances() >> out
+    return tree
+
+
+def test_fallback_without_networkx(no_networkx):
+    """Two sequential sugiyama builds must degrade gracefully without networkx."""
+    # First tree: clean ImportError -> warns + falls back. This works today.
+    with pytest.warns(UserWarning, match="networkx"):
+        _build("FirstNoNX")
+
+    # Second tree: this is where the stale namespace path used to raise
+    # KeyError: 'nodebpy.lib.nodearrange', escaping `except ImportError`.
+    second = _build("SecondNoNX")
+
+    # The tree should still have been built and arranged (simple fallback).
+    assert len(second.tree.nodes) > 0

tests/test_usecases.py

@@ -1024,3 +1024,24 @@ def test_geometryscript_city_builder(snapshot):
         g.JoinGeometry((curve_mesh, buildings)) >> tree.outputs.geometry("Result")
 
     assert snapshot == tree._repr_markdown_()
+
+
+def test_active_grid_positions(snapshot):
+    with g.tree("Active Grid Positions", arrange='simple') as tree:
+        tree.tree.show_modifier_manage_panel = True
+
+        grid = tree.inputs.float("Grid", hide_value=True, structure_type="GRID")
+        points_output = tree.outputs.geometry("Points")
+
+        points = g.GridToPoints.float(grid)
+        indices = g.CombineXYZ(points.o.x, points.o.y, points.o.z).o.vector
+
+        (
+            points.o.points
+            >> g.StoreNamedAttribute.point.vector(name="ix", value=indices)
+            >> g.StoreNamedAttribute.point.boolean(name="value", value=points.o.value)
+            >> g.DeleteGeometry(selection=points.o.is_tile)
+            >> points_output
+        )
+
+    assert snapshot == tree._repr_markdown_()