Defer office runtime preparation during startup

plugins/_office/extensions/python/startup_migration/_20_office_routes.py

@@ -1,16 +1,47 @@
 from __future__ import annotations
 
+import threading
+from typing import Any
+
 from helpers.extension import Extension
 from helpers.print_style import PrintStyle
 from plugins._office import hooks
 from plugins._office.helpers import libreoffice_desktop_routes
 
 
+_startup_preparation_thread: threading.Thread | None = None
+
+
 class OfficeStartupCleanup(Extension):
     def execute(self, **kwargs):
         libreoffice_desktop_routes.install_route_hooks()
-        result = hooks.cleanup_stale_runtime_state()
-        if result.get("errors"):
-            PrintStyle.warning("Office runtime preparation reported errors:", result["errors"])
-        elif result.get("installed") or result.get("removed"):
-            PrintStyle.info("Office runtime prepared:", result)
+        _start_background_runtime_preparation()
+
+
+def _start_background_runtime_preparation() -> threading.Thread:
+    global _startup_preparation_thread
+
+    if _startup_preparation_thread and _startup_preparation_thread.is_alive():
+        return _startup_preparation_thread
+
+    _startup_preparation_thread = threading.Thread(
+        target=_prepare_runtime_safely,
+        name="a0-office-runtime-preparation",
+        daemon=True,
+    )
+    _startup_preparation_thread.start()
+    return _startup_preparation_thread
+
+
+def _prepare_runtime_safely() -> None:
+    try:
+        _log_runtime_preparation_result(hooks.cleanup_stale_runtime_state())
+    except Exception as exc:
+        PrintStyle.warning("Office runtime preparation failed:", exc)
+
+
+def _log_runtime_preparation_result(result: dict[str, Any]) -> None:
+    if result.get("errors"):
+        PrintStyle.warning("Office runtime preparation reported errors:", result["errors"])
+    elif result.get("installed") or result.get("removed"):
+        PrintStyle.info("Office runtime prepared:", result)

tests/test_office_document_store.py

@@ -686,6 +686,8 @@ def test_cleanup_hook_removes_stale_runtime_state_idempotently(tmp_path, monkeyp
 
 def test_office_startup_defers_persistent_desktop_runtime(monkeypatch):
     calls = []
+    cleanup_calls = []
+    started_threads = []
     routes_module = types.ModuleType("plugins._office.helpers.libreoffice_desktop_routes")
     routes_module.install_route_hooks = lambda: calls.append("routes")
     monkeypatch.setitem(sys.modules, "plugins._office.helpers.libreoffice_desktop_routes", routes_module)
@@ -700,14 +702,35 @@ def test_office_startup_defers_persistent_desktop_runtime(monkeypatch):
     monkeypatch.setattr(
         office_startup.hooks,
         "cleanup_stale_runtime_state",
-        lambda: {"ok": True, "errors": [], "installed": [], "removed": []},
+        lambda: cleanup_calls.append("cleanup") or {"ok": True, "errors": [], "installed": [], "removed": []},
     )
 
+    class FakeThread:
+        def __init__(self, *, target, name, daemon):
+            self.target = target
+            self.name = name
+            self.daemon = daemon
+
+        def is_alive(self):
+            return False
+
+        def start(self):
+            started_threads.append(self)
+
+    monkeypatch.setattr(office_startup.threading, "Thread", FakeThread)
+
     office_startup.OfficeStartupCleanup(agent=None).execute()
 
     assert calls == ["routes"]
+    assert cleanup_calls == []
+    assert len(started_threads) == 1
+    assert started_threads[0].name == "a0-office-runtime-preparation"
+    assert started_threads[0].daemon is True
     assert not hasattr(office_startup, "libreoffice_desktop")
 
+    started_threads[0].target()
+    assert cleanup_calls == ["cleanup"]
+
 
 def test_cleanup_hook_reruns_when_stale_packages_exist_after_old_marker(tmp_path, monkeypatch):
     marker = tmp_path / "state" / "cleanup.done"