refactor(webui): keep sidebar index out of session manager

tests/webui/test_session_list_index.py

@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+import nanobot.webui.session_list_index as session_list_index
+from nanobot.session.manager import SessionManager
+
+
+def test_webui_session_list_reuses_valid_index_without_scanning_files(
+    tmp_path: Path,
+    monkeypatch,
+) -> None:
+    manager = SessionManager(tmp_path)
+    session = manager.get_or_create("websocket:indexed")
+    session.add_message("user", "indexed preview")
+    manager.save(session)
+
+    assert list_webui_sessions(manager)[0]["preview"] == "indexed preview"
+
+    def fail_scan(session_manager: SessionManager, path: Path) -> None:
+        raise AssertionError(f"unexpected session file scan: {path}")
+
+    monkeypatch.setattr(session_list_index, "_scan_session_row", fail_scan)
+
+    rows = list_webui_sessions(manager)
+
+    assert rows[0]["key"] == "websocket:indexed"
+    assert rows[0]["preview"] == "indexed preview"
+
+
+def test_webui_session_list_rescans_only_changed_file(tmp_path: Path, monkeypatch) -> None:
+    manager = SessionManager(tmp_path)
+    first = manager.get_or_create("websocket:first")
+    first.add_message("user", "first")
+    manager.save(first)
+    second = manager.get_or_create("websocket:second")
+    second.add_message("user", "second before")
+    manager.save(second)
+
+    assert {row["preview"] for row in list_webui_sessions(manager)} == {"first", "second before"}
+
+    second.messages.clear()
+    second.add_message("user", "second after")
+    manager.save(second)
+
+    original_scan = session_list_index._scan_session_row
+    scanned: list[str] = []
+
+    def record_scan(session_manager: SessionManager, path: Path) -> dict | None:
+        scanned.append(path.name)
+        return original_scan(session_manager, path)
+
+    monkeypatch.setattr(session_list_index, "_scan_session_row", record_scan)
+
+    rows = list_webui_sessions(manager)
+
+    assert scanned == [manager._get_session_path("websocket:second").name]
+    assert {row["preview"] for row in rows} == {"first", "second after"}
+
+
+def test_webui_session_list_drops_deleted_index_rows(tmp_path: Path) -> None:
+    manager = SessionManager(tmp_path)
+    session = manager.get_or_create("websocket:deleted")
+    session.add_message("user", "gone")
+    manager.save(session)
+
+    assert list_webui_sessions(manager)[0]["key"] == "websocket:deleted"
+
+    assert manager.delete_session("websocket:deleted") is True
+
+    assert list_webui_sessions(manager) == []
+
+
+def list_webui_sessions(manager: SessionManager) -> list[dict]:
+    return session_list_index.list_webui_sessions(manager)