BMesh: Python: Add minimal API test for bmesh.

Hopefully will avoid critical failures like #140451 in the future.

tests/python/CMakeLists.txt

@@ -261,6 +261,11 @@ add_blender_test(
   --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_text.py
 )
 
+add_blender_test(
+  script_pyapi_bmesh
+  --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_bmesh.py
+)
+
 add_blender_test(
   script_pyapi_grease_pencil
   --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_grease_pencil.py

tests/python/bl_pyapi_bmesh.py

@@ -0,0 +1,31 @@
+# SPDX-FileCopyrightText: 2025 Blender Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+# ./blender.bin --background --python tests/python/bl_pyapi_bmesh.py -- --verbose
+import bmesh
+import unittest
+
+
+class TestBMeshBasic(unittest.TestCase):
+
+    def test_create_uvsphere(self):
+        bm = bmesh.new()
+        bmesh.ops.create_uvsphere(
+            bm,
+            u_segments=8,
+            v_segments=5,
+            radius=1.0,
+        )
+
+        self.assertEqual(len(bm.verts), 34)
+        self.assertEqual(len(bm.edges), 72)
+        self.assertEqual(len(bm.faces), 40)
+
+        bm.free()
+
+
+if __name__ == "__main__":
+    import sys
+    sys.argv = [__file__] + (sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else [])
+    unittest.main()