From 53c1817956bdceaee83f9ffe57b1c5297b6a4204 Mon Sep 17 00:00:00 2001
From: ThomasV <thomasv@electrum.org>
Date: Wed, 17 Sep 2025 14:42:54 +0200
Subject: [PATCH] tests/test_jsondb.py: add tests that replace a StoredDict
 element after its parent has been removed.

Related: #10000
---
 tests/test_jsondb.py | 49 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/tests/test_jsondb.py b/tests/test_jsondb.py
index 16129e114..eeaf41079 100644
--- a/tests/test_jsondb.py
+++ b/tests/test_jsondb.py
@@ -1,6 +1,7 @@
 import contextlib
 import copy
 import traceback
+import json
 
 import jsonpatch
 from jsonpatch import JsonPatchException
@@ -8,6 +9,7 @@ from jsonpointer import JsonPointerException
 
 from . import ElectrumTestCase
 
+from electrum.json_db import JsonDB
 
 class TestJsonpatch(ElectrumTestCase):
 
@@ -84,3 +86,50 @@ class TestJsonpatch(ElectrumTestCase):
             with self._customAssertRaises(JsonPointerException) as ctx:
                 data2 = jpatch.apply(data1)
             fail_if_leaking_secret(ctx)
+
+
+class TestJsonDB(ElectrumTestCase):
+
+    async def test_jsonpatch_replace_after_remove(self):
+        data = { 'a':{} }
+        # op "add"
+        patches = [{"op": "add", "path": "/a/b", "value": "42"}]
+        jpatch = jsonpatch.JsonPatch(patches)
+        data = jpatch.apply(data)
+        # remove
+        patches = [{"op": "remove", "path": "/a/b"}]
+        jpatch = jsonpatch.JsonPatch(patches)
+        data = jpatch.apply(data)
+        # replace
+        patches = [{"op": "replace", "path": "/a/b", "value": "43"}]
+        jpatch = jsonpatch.JsonPatch(patches)
+        with self.assertRaises(JsonPatchException):
+            data = jpatch.apply(data)
+
+    async def test_jsondb_replace_after_remove(self):
+        data = { 'a': {'b': {'c': 0}}}
+        db = JsonDB(repr(data))
+        a = db.get_dict('a')
+        # remove
+        b = a.pop('b')
+        self.assertEqual(len(db.pending_changes), 1)
+        # replace item. this must not been written to db
+        b['c'] = 42
+        self.assertEqual(len(db.pending_changes), 1)
+        patches = json.loads('[' + ','.join(db.pending_changes) + ']')
+        jpatch = jsonpatch.JsonPatch(patches)
+        data = jpatch.apply(data)
+
+    async def test_jsondb_replace_after_remove_nested(self):
+        data = { 'a': {'b':{'c':0}}}
+        db = JsonDB(repr(data))
+        # remove
+        a = db.data.pop('a')
+        self.assertEqual(len(db.pending_changes), 1)
+        b = a['b']
+        # replace item. this must not be written to db
+        b['c'] = 42
+        self.assertEqual(len(db.pending_changes), 1)
+        patches = json.loads('[' + ','.join(db.pending_changes) + ']')
+        jpatch = jsonpatch.JsonPatch(patches)
+        data = jpatch.apply(data)