Release exp-v0.52.177: scope aux-title test module stubs (#6661) (#6848)

* test(#6630): isolate auxiliary client fixtures

* test(#6630): route both aux-title suites through one scoped module stub

* test(#6630): drop dead import and record the patch.dict restore constraint

* Release exp-v0.52.177: scope auxiliary-title test module stubs, stop cross-file sys.modules leak (#6661)

---------

Co-authored-by: Rod Boev <rod.boev@gmail.com>
Co-authored-by: nesquena-hermes <nesquena-hermes@users.noreply.github.com>

CHANGELOG.md

@@ -11,6 +11,8 @@
 
 - **Internal: removed a dead `rowIndex` parameter from the settled-scene row projector.** `attachLiveStream`'s `pushRow` helper carried an unused positional index left over from before final-segment eligibility moved to a row-identity `WeakSet`; dropping it is a pure no-op refactor (differential execution confirms byte-identical settled scenes — ordering, dedupe, final-prefix suppression, and sequence assignment all unchanged). Thanks @webtecnica. (#6258)
 
+- **Internal: auxiliary-title test suites no longer leak a synthetic `agent` module across the process.** `test_title_aux_routing.py` and `test_2235_initial_aux_title.py` installed stub `agent` / `agent.auxiliary_client` modules via `sys.modules.setdefault` at import time and never removed them, so any later test importing `agent.context_compressor` in the same process got the stub and failed (breaking `test_issue4685_post_compression_context_metering.py` by run order). Both suites now route the install through a shared `tests/_aux_client_helpers.py` chokepoint scoped with `unittest.mock.patch.dict`, plus four tests covering restore-by-identity, absent-key cleanup, present-but-`None` preservation, and restore-on-raise. Test-only, no production change. Thanks @rodboev. (#6661, #6630)
+
 - **Internal: clarified the transcript-virtualization boot comment (opt-in default retained).** The comment above the boot-time `_virtualizeTranscript` apply now records that the #4346 Phase B footer-jitter fix resolved the original scroll-up flicker root cause, while virtualization stays opt-in (default OFF) until battle-tested further. Zero behavior change — the apply predicate, settings-load fallback, checkbox, and server default all remain opt-in/OFF and in agreement. Thanks @webtecnica. (#6318, #6155)
 
 - **Internal: added regression coverage for the empty-`tool_calls` drop on the metadata-restoration mirror path.** `_api_safe_message_positions()` must apply the same `tool_calls: []` drop as the main API sanitizer (#5737) so metadata restoration never treats a `tool_calls: []` row as a distinct message; a new test pins that empty arrays lose the key while populated tool-call chains (and their tool results) survive untouched. Test-only, no production change. Thanks @webtecnica. (#6803, #6796)

tests/_aux_client_helpers.py

@@ -0,0 +1,52 @@
+"""Shared scaffolding for the auxiliary title-generation test suites.
+
+``test_title_aux_routing.py`` and ``test_2235_initial_aux_title.py`` both need
+``agent.auxiliary_client`` importable so ``api.streaming`` can be patched
+against it. Both used to install synthetic modules at import time with
+``sys.modules.setdefault`` and never remove them, so whichever ran first left
+the stub in place for the rest of the process and the next file to import
+``agent.context_compressor`` got the stub instead of the real module (#6630).
+
+Scope the install to the test that needs it and let ``mock.patch.dict`` own the
+restore: it snapshots the mapping and puts it back on exit, so a key that was
+absent is deleted, a key that was present is restored by identity, and a key
+holding ``None`` stays ``None``. ``tests/test_4413_seed_provider_models.py``
+already stubs ``sys.modules`` this way, including the ``None`` case.
+
+One constraint that comes with it: ``patch.dict`` restores by clearing the
+mapping and replacing it wholesale, so any module first imported inside the
+scope is evicted on exit and re-imported later as a new object. That is
+harmless for these suites, which import everything they touch at collection
+time, but it is the thing to check before reusing this helper around code
+that imports lazily.
+"""
+from __future__ import annotations
+
+import sys
+import types
+from unittest import mock
+
+
+def auxiliary_client_modules():
+    """Context manager installing stub ``agent`` / ``agent.auxiliary_client``.
+
+    The stubs are fresh objects owned by this helper, so the ``auxiliary_client``
+    attribute is set on our own module and no pre-existing ``agent`` module is
+    mutated. Restoration is therefore entirely ``patch.dict``'s job.
+    """
+    agent_stub = types.ModuleType("agent")
+    auxiliary_client_stub = types.ModuleType("agent.auxiliary_client")
+    agent_stub.auxiliary_client = auxiliary_client_stub
+    return mock.patch.dict(
+        sys.modules,
+        {"agent": agent_stub, "agent.auxiliary_client": auxiliary_client_stub},
+    )
+
+
+def patch_tg_config(config_dict):
+    """Make ``_get_auxiliary_task_config`` return ``config_dict``."""
+    return mock.patch(
+        "agent.auxiliary_client._get_auxiliary_task_config",
+        return_value=config_dict,
+        create=True,
+    )

tests/test_2235_initial_aux_title.py

@@ -10,24 +10,29 @@ Covers:
   3. Refresh path parity — configured aux routing still applies to the
      adaptive title refresh path.
 """
-import sys
 import threading
-import types
 import unittest
 from unittest.mock import MagicMock, patch
 
-# Stub agent.auxiliary_client so it is importable in the test environment
-# (the real package lives in hermes-agent, which is not installed here).
-_agent_stub = types.ModuleType('agent')
-_aux_stub = types.ModuleType('agent.auxiliary_client')
-sys.modules.setdefault('agent', _agent_stub)
-sys.modules.setdefault('agent.auxiliary_client', _aux_stub)
-_agent_stub.auxiliary_client = _aux_stub
+import pytest
+
+from tests._aux_client_helpers import auxiliary_client_modules, patch_tg_config
+
+
+@pytest.fixture(autouse=True)
+def _install_auxiliary_client_modules():
+    """Scope the synthetic hermes-agent modules to each test (#6630).
+
+    This file carried the same unscoped sys.modules.setdefault install as
+    test_title_aux_routing.py, so it leaked the stub the same way.
+    """
+    with auxiliary_client_modules():
+        yield
 
 
 def _patch_tg_config(config_dict):
     """Return a patch context manager that makes _get_auxiliary_task_config return config_dict."""
-    return patch('agent.auxiliary_client._get_auxiliary_task_config', return_value=config_dict, create=True)
+    return patch_tg_config(config_dict)
 
 
 def _make_provisional_session(user_text, assistant_text='Here is the answer.'):

tests/test_title_aux_routing.py

@@ -13,18 +13,73 @@ import types
 import unittest
 from unittest.mock import MagicMock, patch
 
-# Stub agent.auxiliary_client so it is importable in the test environment
-# (the real package lives in hermes-agent, which is not installed here).
-_agent_stub = types.ModuleType('agent')
-_aux_stub = types.ModuleType('agent.auxiliary_client')
-sys.modules.setdefault('agent', _agent_stub)
-sys.modules.setdefault('agent.auxiliary_client', _aux_stub)
-_agent_stub.auxiliary_client = _aux_stub
+import pytest
+
+from tests._aux_client_helpers import auxiliary_client_modules, patch_tg_config
+
+
+@pytest.fixture(autouse=True)
+def _install_auxiliary_client_modules():
+    """Scope the synthetic hermes-agent modules to each test (#6630)."""
+    with auxiliary_client_modules():
+        yield
 
 
 def _patch_tg_config(config_dict):
     """Return a patch context manager that makes _get_auxiliary_task_config return config_dict."""
-    return patch('agent.auxiliary_client._get_auxiliary_task_config', return_value=config_dict, create=True)
+    return patch_tg_config(config_dict)
+
+
+class TestAuxiliaryClientModuleRestore(unittest.TestCase):
+    """Restoration properties the #6630 fix depends on.
+
+    These drive the helper directly. The fixture boundary itself is proved by
+    the cross-file run in the PR description: running this file before
+    tests/test_issue4685_post_compression_context_metering.py used to fail that
+    file's agent.context_compressor import and no longer does.
+    """
+
+    def test_prior_modules_restored_by_identity(self):
+        prior_agent = types.ModuleType("agent")
+        prior_aux = types.ModuleType("agent.auxiliary_client")
+        prior_agent.auxiliary_client = prior_aux
+        with patch.dict(sys.modules, {"agent": prior_agent, "agent.auxiliary_client": prior_aux}):
+            with auxiliary_client_modules():
+                self.assertIsNot(sys.modules["agent"], prior_agent)
+                self.assertIsNot(sys.modules["agent.auxiliary_client"], prior_aux)
+            self.assertIs(sys.modules["agent"], prior_agent)
+            self.assertIs(sys.modules["agent.auxiliary_client"], prior_aux)
+            self.assertIs(prior_agent.auxiliary_client, prior_aux)
+
+    def test_absent_keys_removed(self):
+        with patch.dict(sys.modules):
+            sys.modules.pop("agent", None)
+            sys.modules.pop("agent.auxiliary_client", None)
+            with auxiliary_client_modules():
+                self.assertIn("agent", sys.modules)
+                self.assertIn("agent.auxiliary_client", sys.modules)
+            self.assertNotIn("agent", sys.modules)
+            self.assertNotIn("agent.auxiliary_client", sys.modules)
+
+    def test_prior_none_value_preserved(self):
+        """A present-but-None entry is not an absent entry."""
+        with patch.dict(sys.modules, {"agent": None, "agent.auxiliary_client": None}):
+            with auxiliary_client_modules():
+                self.assertIsNotNone(sys.modules["agent"])
+            self.assertIn("agent", sys.modules)
+            self.assertIsNone(sys.modules["agent"])
+            self.assertIsNone(sys.modules["agent.auxiliary_client"])
+
+    def test_restored_after_exception(self):
+        prior_agent = types.ModuleType("agent")
+        prior_aux = types.ModuleType("agent.auxiliary_client")
+        prior_agent.auxiliary_client = prior_aux
+        with patch.dict(sys.modules, {"agent": prior_agent, "agent.auxiliary_client": prior_aux}):
+            with self.assertRaisesRegex(RuntimeError, "boom"):
+                with auxiliary_client_modules():
+                    raise RuntimeError("boom")
+            self.assertIs(sys.modules["agent"], prior_agent)
+            self.assertIs(sys.modules["agent.auxiliary_client"], prior_aux)
 
 
 class TestAuxTitleConfigured(unittest.TestCase):