feat: resolve folder names at any nesting depth in rule-list

The one-level folder map left deeply-nested move/copy targets showing the
raw id. Walk the folder tree breadth-first, descending only into folders
that report children (childFolderCount), so GET count is proportional to
folders-with-children rather than the whole tree. Read-only; partial maps
on error still fall back to raw ids. Test covers a depth-3 folder.

Verified live: all rule folder targets resolve to names; no raw ids remain.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: neilgfoster

plugin/src/msgraph/client.py

@@ -551,33 +551,29 @@ def _resolve_folder_id(token: str, name: str) -> str:
 
 
 def _folder_name_map(token: str) -> dict:
-    """Best-effort id→displayName for mail folders (top level + one level of children).
+    """id→displayName for all mail folders at any nesting depth.
 
-    Lets rule-list show move/copy-to-folder targets by name. Folders nested deeper than one level
-    may stay unresolved; those fall back to the raw id so the output never lies about which folder a
-    rule targets. Read-only (a single GET); failures degrade silently to ids.
+    Lets rule-list show move/copy-to-folder targets by name. Walks the folder tree breadth-first,
+    descending only into folders that report children (``childFolderCount``) so the number of GETs is
+    proportional to the folders-with-children, not the whole tree. Read-only; failures degrade
+    silently, leaving unresolved ids to fall back to the raw id so output never lies about the target.
     """
     names: dict = {}
+    params = {"$top": 200, "$select": "id,displayName,childFolderCount"}
+    # Queue of folder-listing paths to fetch; seed with the top level.
+    pending = ["/me/mailFolders"]
     try:
-        data = _graph_get(
-            token,
-            "/me/mailFolders",
-            params={
-                "$top": 200,
-                "$select": "id,displayName",
-                "$expand": "childFolders($select=id,displayName)",
-            },
-        )
+        while pending:
+            data = _graph_get(token, pending.pop(), params=params)
+            for f in data.get("value", []):
+                fid = f.get("id")
+                if not fid:
+                    continue
+                names[fid] = f.get("displayName", "")
+                if f.get("childFolderCount", 0):
+                    pending.append(f"/me/mailFolders/{urllib.parse.quote(fid, safe='')}/childFolders")
     except SteerError:
-        return names
-
-    def walk(folders):
-        for f in folders:
-            if f.get("id"):
-                names[f["id"]] = f.get("displayName", "")
-            walk(f.get("childFolders") or [])
-
-    walk(data.get("value", []))
+        pass  # partial map is fine — unresolved ids render as raw ids
     return names
 
 

tests/test_client.py

@@ -296,8 +296,8 @@ def test_renders_non_header_predicates_and_actions(self):
         # No false "(other criteria)" / "(other action)" placeholder leaks through.
         self.assertNotIn("other criteria", out)
 
-    def test_resolves_move_to_folder_id_to_name(self):
-        # rule-list should show the folder NAME, not the opaque id, for move/copy actions.
+    def test_resolves_deeply_nested_folder_id_to_name(self):
+        # rule-list shows the folder NAME, resolved at ANY nesting depth, not the opaque id.
         self._sign_in("Mail.Read MailboxSettings.Read offline_access")
         rules = {
             "value": [
@@ -306,34 +306,38 @@ def test_resolves_move_to_folder_id_to_name(self):
                     "displayName": "Filed",
                     "isEnabled": True,
                     "conditions": {"senderContains": ["x@y.com"]},
-                    "actions": {"moveToFolder": "child-1", "copyToFolder": "unknown-id"},
+                    "actions": {"moveToFolder": "grandchild-1", "copyToFolder": "unknown-id"},
                 }
             ]
         }
-        folders = {
-            "value": [
-                {
-                    "id": "top-1",
-                    "displayName": "Top",
-                    "childFolders": [{"id": "child-1", "displayName": "House 2026"}],
-                }
-            ]
+        # Folder tree served across the child-folder endpoints (top → child → grandchild).
+        folder_tree = {
+            "/me/mailFolders": [{"id": "top-1", "displayName": "Top", "childFolderCount": 1}],
+            "/me/mailFolders/top-1/childFolders": [
+                {"id": "child-1", "displayName": "Mid", "childFolderCount": 1}
+            ],
+            "/me/mailFolders/child-1/childFolders": [
+                {"id": "grandchild-1", "displayName": "House 2026", "childFolderCount": 0}
+            ],
         }
-        out = self._render(rules, folders)
-        self.assertIn('move to folder: "House 2026"', out)  # nested child resolved
-        self.assertNotIn("child-1", out)
+        out = self._render(rules, folder_tree)
+        self.assertIn('move to folder: "House 2026"', out)  # depth-3 child resolved
+        self.assertNotIn("grandchild-1", out)
         self.assertIn("copy to folder: unknown-id", out)  # unresolved id shown raw, not hidden
 
-    def _render(self, payload, folders=None):
+    def _render(self, payload, folder_tree=None):
         import contextlib
         import io
 
         def responder(method, url, **kw):
-            if "/mailFolders/inbox/messageRules" in url:
+            if "/messageRules" in url:
                 return payload
-            if "/mailFolders" in url:
-                return folders or {"value": []}
-            return payload
+            if folder_tree:
+                for path, value in folder_tree.items():
+                    # Match the path portion of the URL, ignoring the query string.
+                    if url.split("?", 1)[0].endswith(path):
+                        return {"value": value}
+            return {"value": []}
 
         client._http = _HttpRecorder(responder)
         buf = io.StringIO()