Fixing bug when attempting to edit a cell geometry

doc/source/changelog.rst

@@ -1,6 +1,13 @@
 MontePy Changelog
 =================
 
+#Next Version#
+--------------
+
+**Bug Fixes**
+
+* Fixed a bug raised in an edge case when editing cell geometry, by making the error clearer (:issue:`558`).
+
 0.4.1
 --------------
 

montepy/surfaces/half_space.py

@@ -191,6 +191,14 @@ def _add_new_children_to_cell(self, other):
             (cells, surfaces), (self._cell.complements, self._cell.surfaces)
         ):
             for item in container:
+                if not isinstance(
+                    item, (montepy.surfaces.surface.Surface, montepy.Cell)
+                ):
+                    raise IllegalState(
+                        f"The geometry was not fully initialized, and cannot be changed. "
+                        f"The offending cell is {self._cell}. "
+                        f"Run cell.update_pointers."
+                    )
                 if item not in parent:
                     parent.append(item)
 

montepy/surfaces/surface.py

@@ -286,21 +286,8 @@ def __lt__(self, other):
         return self.number < other.number
 
     def __eq__(self, other):
-        return (
-            self.number == other.number
-            and self.surface_type == other.surface_type
-            and self.is_reflecting == other.is_reflecting
-            and self.is_white_boundary == other.is_white_boundary
-            and self.surface_constants == other.surface_constants
-        )
-
-    def __ne__(self, other):
-        return not self == other
-
-    def __hash__(self):
-        return hash((self.number, str(self.surface_type)))
-
-    def __eq__(self, other):
+        if not isinstance(other, type(self)):
+            return False
         return (
             self.number == other.number
             and self.surface_type == other.surface_type

pyproject.toml

@@ -37,6 +37,7 @@ dependencies = [
 [project.optional-dependencies]
 test = [
 	"coverage[toml]>=6.3.2", 
+	"hypothesis",
 	"pytest", 
 	"pytest-profiling",
 	"montepy[build]",

tests/test_geom_integration.py

@@ -0,0 +1,40 @@
+from hypothesis import given
+import hypothesis.strategies as st
+
+import montepy
+
+import pytest
+
+geom_pair = st.tuples(st.integers(min_value=1), st.booleans())
+
+
+@given(
+    st.integers(min_value=1), st.lists(geom_pair, min_size=1, unique_by=lambda x: x[0])
+)
+def test_build_arbitrary_cell_geometry(first_surf, new_surfaces):
+    input = montepy.input_parser.mcnp_input.Input(
+        [f"1 0 {first_surf} imp:n=1"], montepy.input_parser.block_type.BlockType.CELL
+    )
+    cell = montepy.Cell(input)
+    surf = montepy.surfaces.surface.Surface()
+    surf.number = first_surf
+    cell.update_pointers([], [], montepy.surface_collection.Surfaces([surf]))
+    for surf_num, operator in new_surfaces:
+        surf = montepy.surfaces.surface.Surface()
+        surf.number = surf_num
+        if operator:
+            cell.geometry &= +surf
+        else:
+            cell.geometry |= -surf
+    assert len(cell.geometry) == len(new_surfaces) + 1
+
+
+def test_cell_geometry_set_warns():
+    input = montepy.input_parser.mcnp_input.Input(
+        [f"1 0 -1 imp:n=1"], montepy.input_parser.block_type.BlockType.CELL
+    )
+    cell = montepy.Cell(input)
+    with pytest.raises(montepy.errors.IllegalState):
+        surf = montepy.surfaces.surface.Surface()
+        surf.number = 5
+        cell.geometry &= +surf