Report .dbz write failures as Error

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/tests/test_dbz.py b/tests/test_dbz.py
index 7bcf69a..35c7699 100644
--- a/tests/test_dbz.py
+++ b/tests/test_dbz.py
@@ -24,6 +24,7 @@ import tempfile
 import unittest
 from pathlib import Path
 
+from generat3d import Error
 from generat3d.dbz import build, orientation_quat, write
 from generat3d.library import Library
 from generat3d.scene import load
@@ -77,3 +78,8 @@ class DbzTest(unittest.TestCase):
             with self.assertRaises(TypeError):
                 write({"bad": object()}, out)
             self.assertEqual(list(Path(d).iterdir()), [])
+
+    def test_os_error_becomes_error(self):
+        with tempfile.TemporaryDirectory() as d:
+            with self.assertRaisesRegex(Error, "cannot write"):
+                write(self.doc, Path(d) / "missing" / "s.dbz")