Added tests for backend watching tree diff, fixed bugs.

cista/protocol.py

@@ -120,6 +120,9 @@ class FileEntry(msgspec.Struct, array_like=True):
     size: int
     isfile: int
 
+    def __repr__(self):
+        return self.key or "FileEntry()"
+
 
 class Update(msgspec.Struct, array_like=True):
     ...
@@ -137,6 +140,10 @@ class UpdIns(Update, tag="i"):
     items: list[FileEntry]
 
 
+class UpdateMessage(msgspec.Struct):
+    update: list[UpdKeep | UpdDel | UpdIns]
+
+
 class Space(msgspec.Struct):
     disk: int
     free: int

cista/watching.py

@@ -282,13 +282,11 @@ def format_update(old, new):
 
         del_count = 0
         rest = new[nidx:]
-        while old[oidx] not in rest:
+        while oidx < len(old) and old[oidx] not in rest:
             del_count += 1
             oidx += 1
-
         if del_count:
             update.append(UpdDel(del_count))
-            oidx += 1
             continue
 
         insert_items = []