test: wait for an approval dialog to compose before reading it

tests/evals/operation_app.py

@@ -725,7 +725,25 @@ def _apply_intervention(self) -> None:
                 f"{self._journey.id}: dialog_intervention replacement did not apply"
             )
 
+    async def _await_dialog_composed(self, pilot: Any) -> None:
+        """Wait until a current approval dialog has its widgets, or closes.
+
+        Textual makes a pushed screen current before it composes the screen's
+        widgets, and a loaded runner can poll in between (#478): reading the
+        title then would find none. A dialog that closes first is left to
+        `handle`, which already treats it as closed before a decision.
+        """
+        screen = self._app.screen
+        if not isinstance(screen, ConfirmScreen):
+            return
+        await until(
+            pilot,
+            lambda: self._app.screen is not screen or bool(screen.query(".confirm-title")),
+            label="approval dialog composed",
+        )
+
     async def handle(self, pilot: Any) -> None:
+        await self._await_dialog_composed(pilot)
         screen = self._app.screen
         if not isinstance(screen, ConfirmScreen):
             if self._remaining <= 0 or not self._dialog_seen:

tests/evals/test_operation_journeys.py

@@ -8,6 +8,7 @@
 
 from __future__ import annotations
 
+import asyncio
 import json
 import os
 from collections.abc import AsyncIterator, Callable
@@ -31,6 +32,7 @@
 from korvid.evals.scripted import ScriptedProvider
 from korvid.tools.executor import RecordedExecution, ToolOutcome
 from korvid.tools.structured import dump_yaml
+from korvid.ui.widgets.confirm_screen import ConfirmScreen
 
 from . import operation_app
 from .operation_app import (
@@ -1331,6 +1333,25 @@ def polls_that_miss_every_dialog(
     assert run.audit == ()
 
 
+async def test_a_dialog_still_composing_is_read_once_it_has_its_widgets(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    """Textual makes a pushed screen current before it composes the screen's
+    widgets, and a loaded runner can poll in between (#478). The driver must
+    wait for the dialog's title instead of reading a dialog that has none."""
+    original = ConfirmScreen._compose
+
+    async def slow_compose(self: ConfirmScreen) -> None:
+        await asyncio.sleep(0.3)
+        await original(self)
+
+    monkeypatch.setattr(ConfirmScreen, "_compose", slow_compose)
+    run = await run_scripted_journey("scale-deployment-up", tmp_path)
+    observed = [entry for entry in run.journal if entry["event"] == "dialog_observed"]
+    assert [entry["result"] for entry in observed] == ["matched"]
+    assert run.grade.hard_failures == ()
+
+
 def test_the_replacement_journey_declares_its_intervention_in_the_fixture() -> None:
     """B1: the mid-dialog replacement is fixture data, not test code, so
     `tests.evals.operation_campaign` runs the identical journey."""