test(phase-12.1): repair live browse validation guard

backend/tests/test_nextcloud_live.py

@@ -27,6 +27,7 @@ import logging
 import os
 import re
 import uuid as _uuid
+from contextlib import ExitStack
 from typing import Optional
 from unittest.mock import patch, MagicMock
 
@@ -199,21 +200,43 @@ async def test_nextcloud_adapter_read_only_root_metadata(capfd):
         code = _stable_error_code(exc)
         pytest.skip(f"Adapter construction failed [{code}].")
 
-    # Assert no byte or mutation methods are accessible on the adapter
-    for method_name in ("get_object", "put_object", "delete_object",
-                        "upload_to", "download_from", "copy", "move",
-                        "create_folder", "rename"):
-        assert not callable(getattr(type(adapter), method_name, None)), (
-            f"T-12.1-17: adapter exposes mutation method {method_name!r}"
+    # Later phases may legitimately add byte and mutation capabilities to the
+    # adapter. Phase 12.1's invariant is behavioral: metadata browsing must not
+    # invoke any of them. Guard both the adapter boundary and its WebDAV client
+    # so an accidental call fails before network dispatch (T-12.1-17).
+    forbidden_adapter_methods = ("get_object", "put_object", "delete_object")
+    forbidden_client_methods = ("download_from", "upload_to", "mkdir", "clean")
+    guards = [
+        patch.object(
+            adapter,
+            method_name,
+            side_effect=AssertionError(
+                f"T-12.1-17: list_folder called forbidden adapter method {method_name!r}"
+            ),
         )
+        for method_name in forbidden_adapter_methods
+    ]
+    guards.extend(
+        patch.object(
+            adapter._client,
+            method_name,
+            side_effect=AssertionError(
+                f"T-12.1-17: list_folder called forbidden WebDAV method {method_name!r}"
+            ),
+        )
+        for method_name in forbidden_client_methods
+    )
 
     try:
-        listing = await adapter.list_folder(
-            connection_id=connection_id,
-            user_id=user_id,
-            parent_ref=None,
-            page_token=None,
-        )
+        with ExitStack() as stack:
+            for guard in guards:
+                stack.enter_context(guard)
+            listing = await adapter.list_folder(
+                connection_id=connection_id,
+                user_id=user_id,
+                parent_ref=None,
+                page_token=None,
+            )
     except Exception as exc:
         code = _stable_error_code(exc)
         pytest.fail(