* tests/test_polygons.py: New test.

tests/test_polygons.py

@@ -0,0 +1,22 @@
+# Copyright (C) 2024 Ben Elliston
+#
+# This file 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.
+
+"""A testsuite for the polygons.py module."""
+
+import unittest
+
+from nemo import polygons
+
+
+class TestPolygons(unittest.TestCase):
+    """Tests for polygons.py."""
+
+    def test_centroid(self):
+        """Test _centroid function."""
+        notclosed = [(1, 1), (0, 0), (1, 2), (3, 3)]
+        with self.assertRaises(ValueError):
+            polygons._centroid(notclosed)