Added test for test_util to ensure file absence when open for reading

tests/test_util.py

@@ -1,5 +1,5 @@
 import pathlib
-
+import os
 import aiofiles.os
 import pytest
 
@@ -31,3 +31,26 @@ async def test_ensure_directory_absent(tmp_path: pathlib.Path):
 
     await ensure_absent(path)
     assert not await aiofiles.os.path.exists(path)
+
+
+@pytest.mark.asyncio
+async def test_ensure_absent_on_directory_without_write_permissions(
+    tmp_path: pathlib.Path,
+):
+    # Create a directory
+    path = tmp_path / "test_dir"
+    await aiofiles.os.mkdir(path)
+
+    # Change permissions to remove write access (read and execute only)
+    os.chmod(path, 0o500)
+
+    # Try to remove the directory - should raise a PermissionError or OSError
+    with pytest.raises((PermissionError, OSError)):
+        await ensure_absent(path)
+
+    # Clean up by restoring write permissions to allow removal after test
+    os.chmod(path, 0o700)
+    await ensure_absent(path)
+
+    # Ensure the directory was successfully cleaned up
+    assert not await aiofiles.os.path.exists(path)