From 76e08ebea517c15e393912504a924026b7923255 Mon Sep 17 00:00:00 2001
From: teknium1 <127238744+teknium1@users.noreply.github.com>
Date: Wed, 23 Sep 2026 08:35:24 -0700
Subject: [PATCH] test: restored tests exercise their claim instead of passing
 vacuously

Independent review of #120220 found restored tests that could pass without
reaching the code they name. Each fix below was A/B'd against a sabotaged
production line (red) and the real one (green).

- test_clarify_progress_leak: the fake agent slept 2x0.35 s as its only sync.
  It now waits (<= 5 s) for the progress task's first bubble; the queue is
  FIFO, so a leaked clarify bubble is what lands first. Reverting the clarify
  skip in run_turn_runner goes red on the leaked JSON.
- test_desktop_lifecycle_windows_live holder-scan case: the kanban row was
  rebuilt after the serve kill, re-reading the dead pid; NoSuchProcess was
  swallowed into an empty scan and returned False without reaching the
  classifier. Rows are now snapshotted while both processes live; a
  classifier that accepts everything goes red (the old version stayed green).
- *_windows_live (control socket, desktop lifecycle, plan reconciliation,
  shim fail-closed): fixed time.sleep settles become bounded waits on the
  real condition (argv visible to psutil, pipe gone, handle released) and
  child readline() calls get a 60 s bound.
- test_gateway_proc_fallback BSD ps case: drop the is_windows stub and mark
  it linux_only like its neighbour; a revert to `ps -A eww` goes red.
- test_delivery_ledger_single_connection counts only connections to the
  ledger's own database, not every sqlite3.connect in the process; pruning on
  a second connection goes red.
- test_codex_models: the hardcoded gpt-5.6 list becomes a relationship to
  DEFAULT_CODEX_MODELS and the forward-compat table; adding a -pro slug to
  either goes red.
- group-chat-view inline-code: the renderer stub wrapped the code in .aui-md,
  which the generic inline-code rule themes on its own, so the room's
  data-slot rule was never tested. Without the wrapper, renaming the room's
  data-slot goes red.
---
 .../group-chat-view.inline-code.test.tsx      | 22 ++++----
 tests/gateway/test_clarify_progress_leak.py   | 29 +++++++++--
 .../test_control_socket_windows_live.py       | 43 +++++++++++++---
 .../test_delivery_ledger_single_connection.py | 10 +++-
 tests/hermes_cli/test_codex_models.py         | 33 +++++++-----
 .../test_desktop_lifecycle_windows_live.py    | 51 +++++++++++++------
 .../hermes_cli/test_gateway_proc_fallback.py  |  4 +-
 .../test_plan_reconciliation_windows_live.py  | 24 +++++++--
 .../test_shim_fail_closed_windows_live.py     | 40 +++++++++++++--
 9 files changed, 193 insertions(+), 63 deletions(-)

diff --git a/apps/desktop/src/plugins/hermes-bots/group-chat-view.inline-code.test.tsx b/apps/desktop/src/plugins/hermes-bots/group-chat-view.inline-code.test.tsx
index b9dc2e124c..6e58b8e197 100644
--- a/apps/desktop/src/plugins/hermes-bots/group-chat-view.inline-code.test.tsx
+++ b/apps/desktop/src/plugins/hermes-bots/group-chat-view.inline-code.test.tsx
@@ -8,14 +8,12 @@ import { afterEach, beforeAll, expect, it, vi } from 'vitest'
 
 import { translateBots } from './i18n-test-helper'
 
-// Room bodies render through the shell's message renderer, whose markdown
-// root is `aui-md prose` — the same container the 1:1 chat uses, minus the
-// `[data-slot='aui_assistant-message-content']` ancestor that scopes the
-// themed inline-code rule in styles.css. Without a room-owned hook the room's
-// `<code>` falls through to Tailwind Typography's fixed near-black ink, which
-// is invisible on every dark theme (#114086). The stubs below emit the two
-// shapes the room can produce (renderer path, raw Streamdown fallback) so the
-// real stylesheet's cascade decides, not a regex over the source text.
+// Without a room-owned hook the room's `<code>` falls through to Tailwind
+// Typography's fixed near-black ink, which is invisible on every dark theme
+// (#114086). The renderer stub emits a bare `<code>` with NO `.aui-md`
+// wrapper, so only the room's own `[data-slot='group-chat-message-content']`
+// rule in the real stylesheet can theme it: the cascade decides, not a regex
+// over the source text.
 vi.mock('@hermes/plugin-sdk', async () => {
   const { pluginSdkMock, createGroupGateway } = await import('./group-test-utils')
   const base = await pluginSdkMock(createGroupGateway().host)
@@ -43,11 +41,9 @@ vi.mock('@hermes/plugin-sdk', async () => {
     DialogTitle: () => null,
     Input: () => null,
     MessageTextContent: ({ text }: { text: string }) => (
-      <div className="aui-md prose">
-        <p>
-          set <code data-testid="renderer-code">{text}</code> first
-        </p>
-      </div>
+      <p>
+        set <code data-testid="renderer-code">{text}</code> first
+      </p>
     ),
     Tip: ({ children }: { children: ReactNode }) => children,
     relativeTime: () => 'now',
diff --git a/tests/gateway/test_clarify_progress_leak.py b/tests/gateway/test_clarify_progress_leak.py
index da057c24f6..9763467c38 100644
--- a/tests/gateway/test_clarify_progress_leak.py
+++ b/tests/gateway/test_clarify_progress_leak.py
@@ -12,7 +12,7 @@ the rendered interactive prompt on Slack.
 
 import importlib
 import sys
-import time
+import threading
 import types
 
 import pytest
@@ -29,6 +29,13 @@ class ProgressCaptureAdapter(BasePlatformAdapter):
         super().__init__(PlatformConfig(enabled=True, token="***"), platform)
         self.sent = []
         self.edits = []
+        # Set on the first send/edit. The fake agent (on an executor thread)
+        # waits on it, so the turn cannot end before the progress task has
+        # rendered its first bubble.
+        self.delivered = threading.Event()
+
+    def _record(self, content):
+        self.delivered.set()
 
     async def connect(self, *, is_reconnect: bool = False) -> bool:
         return True
@@ -38,10 +45,12 @@ class ProgressCaptureAdapter(BasePlatformAdapter):
 
     async def send(self, chat_id, content, reply_to=None, metadata=None) -> SendResult:
         self.sent.append({"chat_id": chat_id, "content": content})
+        self._record(content)
         return SendResult(success=True, message_id="m-1")
 
     async def edit_message(self, chat_id, message_id, content) -> SendResult:
         self.edits.append({"chat_id": chat_id, "message_id": message_id, "content": content})
+        self._record(content)
         return SendResult(success=True, message_id=message_id)
 
     async def send_typing(self, chat_id, metadata=None) -> None:
@@ -55,7 +64,15 @@ class ProgressCaptureAdapter(BasePlatformAdapter):
 
 
 class ClarifyThenToolAgent:
-    """Emits a clarify tool.started (with raw args) then a normal tool."""
+    """Emits a clarify tool.started (with raw args) then a normal tool, and
+    returns only once the progress task has delivered its first bubble.
+
+    Both events are queued before that wait, and the queue drains FIFO, so the
+    first bubble is the clarify one if clarify leaks and the terminal one if
+    not. A timeout means nothing drained and fails the test.
+    """
+
+    adapter = None
 
     def __init__(self, **kwargs):
         self.tool_progress_callback = kwargs.get("tool_progress_callback")
@@ -70,9 +87,9 @@ class ClarifyThenToolAgent:
                 "Which environment?",
                 {"question": "Which environment?", "choices": ["staging", "production"]},
             )
-            time.sleep(0.35)
             cb("tool.started", "terminal", "pwd", {})
-            time.sleep(0.35)
+            if not type(self).adapter.delivered.wait(timeout=5.0):
+                raise AssertionError("progress task never delivered a bubble")
         return {"final_response": "done", "messages": [], "api_calls": 1}
 
 
@@ -127,6 +144,7 @@ async def test_clarify_tool_never_renders_progress_bubble(monkeypatch, tmp_path,
     """
     adapter = ProgressCaptureAdapter()
     runner = _make_runner(adapter)
+    monkeypatch.setattr(ClarifyThenToolAgent, "adapter", adapter)
     gateway_run = _install_fakes(monkeypatch, mode)
     monkeypatch.setattr(gateway_run, "_hermes_home", tmp_path)
 
@@ -152,5 +170,6 @@ async def test_clarify_tool_never_renders_progress_bubble(monkeypatch, tmp_path,
     # No clarify progress line at all (verb "Asking" / tool name).
     assert "clarify" not in all_content
     assert "Asking" not in all_content
-    # The unrelated terminal tool still renders progress normally.
+    # The unrelated terminal tool still renders progress normally (and proves
+    # the no-leak asserts above ran against a drained queue).
     assert "pwd" in all_content
diff --git a/tests/gateway/test_control_socket_windows_live.py b/tests/gateway/test_control_socket_windows_live.py
index 723a98fef5..42c3c524e9 100644
--- a/tests/gateway/test_control_socket_windows_live.py
+++ b/tests/gateway/test_control_socket_windows_live.py
@@ -21,8 +21,10 @@ from __future__ import annotations
 
 import json
 import os
+import queue
 import subprocess
 import sys
+import threading
 import time
 from pathlib import Path
 
@@ -32,6 +34,35 @@ pytestmark = pytest.mark.windows_only
 
 PROJECT_ROOT = Path(__file__).resolve().parents[2]
 
+
+def _wait_until(predicate, timeout: float = 15.0, interval: float = 0.05) -> bool:
+    deadline = time.monotonic() + timeout
+    while time.monotonic() < deadline:
+        if predicate():
+            return True
+        time.sleep(interval)
+    return bool(predicate())
+
+
+def _readline(stream, timeout: float = 60.0) -> str:
+    """``stream.readline()`` bounded by *timeout* (a hung child fails, not hangs)."""
+    got: queue.Queue = queue.Queue()
+    threading.Thread(target=lambda: got.put(stream.readline()), daemon=True).start()
+    try:
+        return got.get(timeout=timeout)
+    except queue.Empty:
+        return ""
+
+
+def _argv_visible(pid: int, marker: str) -> bool:
+    """True once the process table shows *pid* with *marker* in its argv."""
+    import psutil
+
+    try:
+        return marker in " ".join(psutil.Process(pid).cmdline())
+    except (psutil.NoSuchProcess, psutil.AccessDenied):
+        return False
+
 _CHILD_CODE = r"""
 import asyncio, os, sys
 sys.path.insert(0, sys.argv[1])
@@ -65,10 +96,10 @@ def live_server(tmp_path: Path):
         text=True,
         cwd=str(PROJECT_ROOT),
     )
-    line = proc.stdout.readline().strip()
+    line = _readline(proc.stdout).strip()
     if not line.startswith("SERVER_STARTED"):
         err = proc.stderr.read() if proc.poll() is not None else ""
-        proc.kill()
+        _kill_tree(proc)
         pytest.fail(f"pipe server child failed to start: {line!r} {err}")
     server_pid = int(line.split()[1])
     yield proc, home, server_pid
@@ -126,9 +157,10 @@ def test_pipe_gone_after_kill_falls_back(live_server, monkeypatch):
 
     assert identify_gateway(home, timeout=5.0) is not None
     _kill_tree(proc)
-    time.sleep(0.5)
 
-    assert identify_gateway(home, timeout=2.0) is None
+    # taskkill /T returns once the tree is signalled; the pipe disappears when
+    # the kernel tears the server's handles down.
+    assert _wait_until(lambda: identify_gateway(home, timeout=0.5) is None)
 
     # Consumer falls back to the state file. That file is a claim, not an
     # identity: its sha classifies a row only when live_gateway_pid_for_home
@@ -163,8 +195,7 @@ def test_pipe_gone_after_kill_falls_back(live_server, monkeypatch):
         stderr=subprocess.DEVNULL,
     )
     try:
-        time.sleep(0.5)
-        assert standin.poll() is None
+        assert _wait_until(lambda: _argv_visible(standin.pid, "gateway")), "stand-in argv never visible"
         _write_state(standin.pid)
         fleet = ur.collect_fleet_versions()
         assert len(fleet) == 1, fleet
diff --git a/tests/gateway/test_delivery_ledger_single_connection.py b/tests/gateway/test_delivery_ledger_single_connection.py
index 450132dd90..049861e71f 100644
--- a/tests/gateway/test_delivery_ledger_single_connection.py
+++ b/tests/gateway/test_delivery_ledger_single_connection.py
@@ -7,17 +7,23 @@ second connection opened after the first one closed.
 from __future__ import annotations
 
 import sqlite3
+from pathlib import Path
 
 from gateway import delivery_ledger as dl
 
 
 def test_recording_a_reply_does_not_open_a_second_connection(tmp_path, monkeypatch):
-    monkeypatch.setattr(dl, "_db_path", lambda: tmp_path / "state.db")
+    db = tmp_path / "state.db"
+    monkeypatch.setattr(dl, "_db_path", lambda: db)
     real_connect = sqlite3.connect
     opened: list[str] = []
 
     def counting_connect(*args, **kwargs):
-        opened.append(str(args[0]) if args else str(kwargs.get("database")))
+        target = args[0] if args else kwargs.get("database")
+        # Only the ledger's own database counts: unrelated sqlite users in the
+        # process (other modules, background threads) must not move the tally.
+        if Path(str(target)).resolve() == db.resolve():
+            opened.append(str(target))
         return real_connect(*args, **kwargs)
 
     monkeypatch.setattr(sqlite3, "connect", counting_connect)
diff --git a/tests/hermes_cli/test_codex_models.py b/tests/hermes_cli/test_codex_models.py
index efd6c48f0a..e73ad6c636 100644
--- a/tests/hermes_cli/test_codex_models.py
+++ b/tests/hermes_cli/test_codex_models.py
@@ -2,29 +2,34 @@ import json
 from unittest.mock import patch
 
 from hermes_cli.codex_models import (
+    _FORWARD_COMPAT_TEMPLATE_MODELS,
+    DEFAULT_CODEX_MODELS,
     get_codex_model_ids,
 )
 
 
-CHATGPT_REJECTED_CODEX_PRO_SLUGS = {
-    "gpt-5.6-sol-pro",
-    "gpt-5.6-terra-pro",
-    "gpt-5.6-luna-pro",
-}
+def _pro_slugs(model_ids):
+    return [m for m in model_ids if m.removesuffix("-900k").endswith("-pro")]
 
 
-def test_curated_codex_fallback_excludes_chatgpt_rejected_pro_slugs(monkeypatch):
-    """OAuth fallback retains real models but never synthesizes rejected ones."""
-    retained_models = {"gpt-5.6-sol", "gpt-5.6-terra", "gpt-5.6-luna"}
+def test_codex_catalog_never_offers_chatgpt_rejected_pro_slugs(monkeypatch, tmp_path):
+    """The ChatGPT Codex OAuth backend 400s every ``-pro`` slug (#52492), so
+    neither the offline fallback nor forward-compat synthesis over a live
+    catalog may offer one, while the fallback still keeps every curated model."""
+    monkeypatch.setenv("CODEX_HOME", str(tmp_path))  # no config.toml default, no cache
+    offline = get_codex_model_ids()
+    assert set(DEFAULT_CODEX_MODELS) <= set(offline)
+    assert _pro_slugs(offline) == []
 
+    # Live discovery returning only template slugs fires every forward-compat
+    # synthesis rule; none of what it adds may be -pro.
+    templates = list(dict.fromkeys(t for _, ts in _FORWARD_COMPAT_TEMPLATE_MODELS for t in ts))
     monkeypatch.setattr(
-        "hermes_cli.codex_models._fetch_models_from_api",
-        lambda access_token: ["gpt-5.5"],
+        "hermes_cli.codex_models._fetch_models_from_api", lambda access_token: templates
     )
-    model_ids = get_codex_model_ids(access_token="codex-access-token")
-
-    assert retained_models.issubset(model_ids)
-    assert CHATGPT_REJECTED_CODEX_PRO_SLUGS.isdisjoint(model_ids)
+    live = get_codex_model_ids(access_token="codex-access-token")
+    assert {synthetic for synthetic, _ in _FORWARD_COMPAT_TEMPLATE_MODELS} <= set(live)
+    assert _pro_slugs(live) == []
 
 
 
diff --git a/tests/hermes_cli/test_desktop_lifecycle_windows_live.py b/tests/hermes_cli/test_desktop_lifecycle_windows_live.py
index 6930032ac6..c77a2b1b2b 100644
--- a/tests/hermes_cli/test_desktop_lifecycle_windows_live.py
+++ b/tests/hermes_cli/test_desktop_lifecycle_windows_live.py
@@ -31,6 +31,25 @@ pytestmark = pytest.mark.windows_only
 PROJECT_ROOT = Path(__file__).resolve().parents[2]
 
 
+def _wait_until(predicate, timeout: float = 15.0, interval: float = 0.05) -> bool:
+    deadline = time.monotonic() + timeout
+    while time.monotonic() < deadline:
+        if predicate():
+            return True
+        time.sleep(interval)
+    return bool(predicate())
+
+
+def _argv_visible(pid: int, marker: str) -> bool:
+    """True once the process table shows *pid* with *marker* in its argv."""
+    import psutil
+
+    try:
+        return marker in " ".join(psutil.Process(pid).cmdline())
+    except (psutil.NoSuchProcess, psutil.AccessDenied):
+        return False
+
+
 @pytest.fixture()
 def sleeper():
     procs: list[subprocess.Popen] = []
@@ -42,8 +61,7 @@ def sleeper():
             stderr=subprocess.DEVNULL,
         )
         procs.append(p)
-        time.sleep(0.5)
-        assert p.poll() is None
+        assert _wait_until(lambda: _argv_visible(p.pid, "time.sleep(120)")), "sleeper argv never visible"
         return p
 
     yield _spawn
@@ -98,8 +116,7 @@ def test_live_supervised_serve_suppresses_cold_start(sleeper, monkeypatch, tmp_p
     # Dead serve → ownership drops → plan returns.
     serve.kill()
     serve.wait()
-    time.sleep(0.5)
-    assert update_cmd._desktop_owns_gateway_lifecycle() is False
+    assert _wait_until(lambda: update_cmd._desktop_owns_gateway_lifecycle() is False)
     token = update_cmd._pause_windows_gateways_for_update()
     assert token is not None and token.get("cold_start_if_installed") is True
 
@@ -116,27 +133,29 @@ def test_holder_scan_fallback_respects_token_classifier(sleeper, monkeypatch, tm
     # Lookalike from the #90778 class — must NOT confer ownership.
     kanban_like = sleeper("-m", "hermes_cli.main", "kanban", "--preserve-cache")
 
-    def fake_holders():
-        import psutil
+    import psutil
 
-        out = []
-        for p in (serve_like, kanban_like):
-            proc = psutil.Process(p.pid)
-            out.append((p.pid, proc.name(), " ".join(proc.cmdline())))
-        return out
+    # Snapshot both holder rows while both processes are alive. Building the
+    # kanban row later (after the serve kill) would re-read the dead serve pid,
+    # raise NoSuchProcess and hand the fallback an empty scan, which returns
+    # False without ever reaching the token classifier.
+    serve_row, kanban_row = (
+        (p.pid, psutil.Process(p.pid).name(), " ".join(psutil.Process(p.pid).cmdline()))
+        for p in (serve_like, kanban_like)
+    )
+    assert "--preserve-cache" in kanban_row[2]
 
     monkeypatch.setattr(
-        "hermes_cli.main._detect_venv_python_processes", fake_holders
+        "hermes_cli.main._detect_venv_python_processes", lambda: [serve_row, kanban_row]
     )
-
     # serve-shaped holder with a live parent (us) → owns
     assert update_cmd._desktop_owns_gateway_lifecycle() is True
 
-    # Only the kanban lookalike left → classifier rejects → does not own
+    # Only the (still live) kanban lookalike left → classifier rejects → does not own
     serve_like.kill()
     serve_like.wait()
+    assert kanban_like.poll() is None
     monkeypatch.setattr(
-        "hermes_cli.main._detect_venv_python_processes",
-        lambda: [fake_holders()[1]],
+        "hermes_cli.main._detect_venv_python_processes", lambda: [kanban_row]
     )
     assert update_cmd._desktop_owns_gateway_lifecycle() is False
diff --git a/tests/hermes_cli/test_gateway_proc_fallback.py b/tests/hermes_cli/test_gateway_proc_fallback.py
index 6a70da35f1..8ce5f93255 100644
--- a/tests/hermes_cli/test_gateway_proc_fallback.py
+++ b/tests/hermes_cli/test_gateway_proc_fallback.py
@@ -114,16 +114,18 @@ class TestProcFallback:
         mock_ps.assert_not_called()  # /proc dir existed, so ps not called
 
 
+@pytest.mark.linux_only
 class TestPsFallbackBsdCompat:
     """The ps fallback must use flags BSD/macOS ps accepts (#73626, #74075).
 
     ``ps -A eww`` fails on macOS (BSD ``e`` is not the procps flag), which
     made gateway discovery silently return nothing whenever /proc is absent.
+    Linux-only like ``TestProcFallback``: the real host selects the POSIX arm
+    and only /proc's absence is faked, to force the ps rung.
     """
 
     def test_ps_fallback_uses_bsd_compatible_flags_and_columns(self):
         with (
-            patch("hermes_cli.gateway.is_windows", return_value=False),
             patch("os.path.isdir", side_effect=lambda p: p != "/proc"),
             patch("hermes_cli.gateway._get_ancestor_pids", return_value=set()),
             patch("subprocess.run") as mock_run,
diff --git a/tests/hermes_cli/test_plan_reconciliation_windows_live.py b/tests/hermes_cli/test_plan_reconciliation_windows_live.py
index 3f6e8825ca..dce4b7e321 100644
--- a/tests/hermes_cli/test_plan_reconciliation_windows_live.py
+++ b/tests/hermes_cli/test_plan_reconciliation_windows_live.py
@@ -25,6 +25,25 @@ import pytest
 pytestmark = [pytest.mark.windows_only, pytest.mark.spawns_gateway_lookalike]
 
 
+def _wait_until(predicate, timeout: float = 15.0, interval: float = 0.05) -> bool:
+    deadline = time.monotonic() + timeout
+    while time.monotonic() < deadline:
+        if predicate():
+            return True
+        time.sleep(interval)
+    return bool(predicate())
+
+
+def _argv_visible(pid: int, marker: str) -> bool:
+    """True once the process table shows *pid* with *marker* in its argv."""
+    import psutil
+
+    try:
+        return marker in " ".join(psutil.Process(pid).cmdline())
+    except (psutil.NoSuchProcess, psutil.AccessDenied):
+        return False
+
+
 def test_plan_reconciliation_live_windows(tmp_path, monkeypatch):
     home = tmp_path / ".hermes"
     home.mkdir()
@@ -43,9 +62,8 @@ def test_plan_reconciliation_live_windows(tmp_path, monkeypatch):
         stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
     )
     try:
-        time.sleep(0.5)
-        assert child.poll() is None
-        assert foreign.poll() is None
+        assert _wait_until(lambda: _argv_visible(child.pid, "gateway")), "stand-in argv never visible"
+        assert _wait_until(lambda: _argv_visible(foreign.pid, "time.sleep(120)")), "sleeper never visible"
 
         import psutil
 
diff --git a/tests/hermes_cli/test_shim_fail_closed_windows_live.py b/tests/hermes_cli/test_shim_fail_closed_windows_live.py
index 8bff93bb86..982ccc45ee 100644
--- a/tests/hermes_cli/test_shim_fail_closed_windows_live.py
+++ b/tests/hermes_cli/test_shim_fail_closed_windows_live.py
@@ -13,8 +13,10 @@ the real rename attempt hitting the real sharing violation.
 from __future__ import annotations
 
 import os
+import queue
 import subprocess
 import sys
+import threading
 import time
 from pathlib import Path
 
@@ -25,6 +27,36 @@ pytestmark = pytest.mark.windows_only
 
 PROJECT_ROOT = Path(__file__).resolve().parents[2]
 
+
+def _wait_until(predicate, timeout: float = 15.0, interval: float = 0.05) -> bool:
+    deadline = time.monotonic() + timeout
+    while time.monotonic() < deadline:
+        if predicate():
+            return True
+        time.sleep(interval)
+    return bool(predicate())
+
+
+def _readline(stream, timeout: float = 60.0) -> str:
+    """``stream.readline()`` bounded by *timeout* (a hung child fails, not hangs)."""
+    got: queue.Queue = queue.Queue()
+    threading.Thread(target=lambda: got.put(stream.readline()), daemon=True).start()
+    try:
+        return got.get(timeout=timeout)
+    except queue.Empty:
+        return ""
+
+
+def _rename_round_trips(path: Path) -> bool:
+    """True once no handle blocks a rename of *path* (the holder is gone)."""
+    probe = path.with_name(path.name + ".probe")
+    try:
+        os.rename(path, probe)
+    except OSError:
+        return False
+    os.rename(probe, path)
+    return True
+
 # Child that opens a file with GENERIC_READ and NO FILE_SHARE_DELETE —
 # the exact sharing mode a running .exe image / desktop backend exhibits.
 _HOLDER_CODE = r"""
@@ -55,7 +87,7 @@ def held_shim(tmp_path: Path):
         stdout=subprocess.PIPE,
         text=True,
     )
-    line = holder.stdout.readline().strip()
+    line = _readline(holder.stdout).strip()
     if line != "HOLDING":
         holder.kill()
         pytest.fail(f"lock-holder child failed: {line!r}")
@@ -129,10 +161,12 @@ def test_release_then_strict_quarantine_succeeds(tmp_path, monkeypatch):
         stdout=subprocess.PIPE,
         text=True,
     )
-    assert holder.stdout.readline().strip() == "HOLDING"
+    assert _readline(holder.stdout).strip() == "HOLDING"
     holder.kill()
     holder.wait()
-    time.sleep(0.3)  # handle teardown
+    # The handle is released when the kernel tears the (possibly trampolined)
+    # holder down, not when wait() returns.
+    assert _wait_until(lambda: _rename_round_trips(scripts / "hermes.exe")), "holder handle never released"
 
     install_ran: list = []
     monkeypatch.setattr(