From 38b2f0ca0f6147b17e2151704e040bff72f75e46 Mon Sep 17 00:00:00 2001
From: Johannes Kirschbauer <hsjobeki@gmail.com>
Date: Fri, 23 May 2025 21:43:09 +0200
Subject: [PATCH] test(persist/util): add test for adding empty submodules

---
 pkgs/clan-cli/clan_lib/persist/util_test.py | 26 +++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/pkgs/clan-cli/clan_lib/persist/util_test.py b/pkgs/clan-cli/clan_lib/persist/util_test.py
index 9ccec35cc..e642d9982 100644
--- a/pkgs/clan-cli/clan_lib/persist/util_test.py
+++ b/pkgs/clan-cli/clan_lib/persist/util_test.py
@@ -1,4 +1,5 @@
 # Functions to test
+from copy import deepcopy
 from typing import Any
 
 import pytest
@@ -253,6 +254,31 @@ def test_update_simple() -> None:
     assert patchset == {"foo.bar": "new value"}
 
 
+def test_update_add_empty_dict() -> None:
+    prios = {
+        "foo": {
+            "__prio": 100,  # <- writeable: "foo"
+            "nix": {"__prio": 100},  # <- non writeable: "foo.nix" (defined in nix)
+        },
+    }
+
+    data_eval: dict = {"foo": {"nix": {}}}
+
+    data_disk: dict = {}
+
+    writeables = determine_writeability(prios, data_eval, data_disk)
+
+    update = deepcopy(data_eval)
+
+    apply_patch(update, "foo.mimi", {})
+
+    patchset, _ = calc_patches(
+        data_disk, update, all_values=data_eval, writeables=writeables
+    )
+
+    assert patchset == {"foo.mimi": {}}  # this is what gets persisted
+
+
 def test_update_many() -> None:
     prios = {
         "foo": {