From 0cf29f1459562ab1278e115da27c989c0bb9df67 Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Wed, 13 Sep 2023 12:49:38 -0500
Subject: [PATCH] Add type checks on Intersection, Union, Complement (#2685)

---
 openmc/region.py                | 10 ++++++++--
 tests/unit_tests/test_region.py | 18 ++++++++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/openmc/region.py b/openmc/region.py
index a2d3b1d0cb..1d54bff8da 100644
--- a/openmc/region.py
+++ b/openmc/region.py
@@ -4,7 +4,6 @@ from copy import deepcopy
 
 import numpy as np
 
-from .checkvalue import check_type
 from .bounding_box import BoundingBox
 
 
@@ -362,6 +361,9 @@ class Intersection(Region, MutableSequence):
 
     def __init__(self, nodes):
         self._nodes = list(nodes)
+        for node in nodes:
+            if not isinstance(node, Region):
+                raise ValueError('Intersection operands must be of type Region')
 
     def __and__(self, other):
         new = Intersection(self)
@@ -450,6 +452,9 @@ class Union(Region, MutableSequence):
 
     def __init__(self, nodes):
         self._nodes = list(nodes)
+        for node in nodes:
+            if not isinstance(node, Region):
+                raise ValueError('Union operands must be of type Region')
 
     def __or__(self, other):
         new = Union(self)
@@ -566,7 +571,8 @@ class Complement(Region):
 
     @node.setter
     def node(self, node):
-        check_type('node', node, Region)
+        if not isinstance(node, Region):
+            raise ValueError('Complement operand must be of type Region')
         self._node = node
 
     @property
diff --git a/tests/unit_tests/test_region.py b/tests/unit_tests/test_region.py
index 086ce64010..2e517c9652 100644
--- a/tests/unit_tests/test_region.py
+++ b/tests/unit_tests/test_region.py
@@ -222,3 +222,21 @@ def test_translate_inplace():
     # Translating a region in-place should *not* produce new surfaces
     region3 = region.translate((0.5, -6.7, 3.9), inplace=True)
     assert str(region) == str(region3)
+
+
+def test_invalid_operands():
+    s = openmc.Sphere()
+    z = 3
+
+    # Intersection with invalid operand
+    with pytest.raises(ValueError, match='must be of type Region'):
+        -s & +z
+
+    # Union with invalid operand
+    with pytest.raises(ValueError, match='must be of type Region'):
+        -s | +z
+
+    # Complement with invalid operand
+    with pytest.raises(ValueError, match='must be of type Region'):
+        openmc.Complement(z)
+