Revert PR #1342's test_issue1195 rewrite — del sys.modules corrupts shared module state

PR #1342's rewrite introduced `del sys.modules['api.config']`, 'api.profiles']`
anti-pattern that breaks tests/test_live_models_ttl_cache.py::test_live_models_cache_is_profile_scoped
(v0.50.252) when run after test_issue1195_*. The pattern is explicitly banned per
~/WebUI/docs/agent-memory/pytest-isolation.md — sibling tests that import api.profiles
later see the wrong (re-imported) module.

Master's version of this test passes 5/5 and uses no del sys.modules calls. The PR's
core /branch feature does NOT depend on this test rewrite — reverting it loses no
coverage of the branching feature.

tests/test_issue1195_session_profile_routing.py

@@ -1,116 +1,81 @@
-"""Regression tests for issue #1195.
+"""Tests for issue #1195: sessions must route to the correct profile directory
+even when that profile directory does not exist yet on disk."""
 
-When the WebUI creates a session for a profile whose directory doesn't exist yet
-(e.g. 'ayan' in ~/.hermes/profiles/ayan/), the session must be routed to that
-profile's sessions dir — NOT to the default ~/.hermes/ dir.  Otherwise sessions
-created in WebUI for 'ayan' appear in TUI under 'awen' or 'default', breaking
-profile isolation.
-"""
-import importlib
 import os
-import sys
 import tempfile
 from pathlib import Path
+from unittest.mock import patch
 
 import pytest
 
-REPO_ROOT = Path(__file__).parent.parent.resolve()
-if str(REPO_ROOT) not in sys.path:
-    sys.path.insert(0, str(REPO_ROOT))
+
+# ── helpers ──────────────────────────────────────────────────────────────────
+
+def _make_hermes_home(base: Path, profile_name: str | None = None) -> Path:
+    """Create a temp HERMES_HOME (with optional profile dir) and return it."""
+    hermes_home = base / ".hermes"
+    hermes_home.mkdir(parents=True, exist_ok=True)
+    if profile_name:
+        (hermes_home / "profiles" / profile_name).mkdir(parents=True, exist_ok=True)
+    return hermes_home
 
 
-def _reload_profiles_module(base_home: Path):
-    """Hot-reload api.profiles with a fresh _DEFAULT_HERMES_HOME."""
-    os.environ["HERMES_BASE_HOME"] = str(base_home)
-    os.environ["HERMES_HOME"] = str(base_home)
+# ── tests ────────────────────────────────────────────────────────────────────
 
-    # Save and remove so we get a fresh import
-    _saved = {name: sys.modules[name] for name in ["api.config", "api.profiles"]
-              if name in sys.modules}
-    for name in ["api.config", "api.profiles"]:
-        if name in sys.modules:
-            del sys.modules[name]
+class TestGetHermesHomeForProfile:
+    """get_hermes_home_for_profile() must return the profile path regardless of
+    whether the directory already exists on disk (#1195)."""
 
-    profiles = importlib.import_module("api.profiles")
+    @pytest.fixture(autouse=True)
+    def _patch_default_home(self, tmp_path):
+        """Patch _DEFAULT_HERMES_HOME to a temp directory for isolation."""
+        from api.profiles import _DEFAULT_HERMES_HOME as real_default
 
-    # Restore so other tests aren't broken
-    sys.modules.update(_saved)
-    return profiles
+        fake_home = tmp_path / ".hermes"
+        fake_home.mkdir(parents=True)
+        with patch("api.profiles._DEFAULT_HERMES_HOME", fake_home):
+            yield fake_home, real_default
 
+    def test_existing_profile_returns_profile_dir(self, _patch_default_home):
+        fake_home, _ = _patch_default_home
+        from api.profiles import get_hermes_home_for_profile
 
-def test_get_hermes_home_routes_to_profile_dir_when_dir_missing():
-    """Issue #1195: get_hermes_home_for_profile should return the profile dir
-    even when that directory does not exist yet.
-
-    WebUI can create sessions for a profile before TUI has ever initialised it.
-    The routing must NOT fallback to default home in that case — otherwise
-    session files end up in the wrong profile directory.
-    """
-    with tempfile.TemporaryDirectory() as td:
-        base = Path(td) / ".hermes"
-        base.mkdir(parents=True)
-        # Deliberately NO profiles/ayan subdir — simulating a WebUI-only profile
-
-        profiles = _reload_profiles_module(base)
-
-        result = profiles.get_hermes_home_for_profile("ayan")
-        expected = base / "profiles" / "ayan"
-
-        assert result == expected, (
-            f"Expected {expected}, got {result}. "
-            "Sessions for 'ayan' would be saved to the wrong directory!"
-        )
-
-
-def test_get_hermes_home_routes_to_existing_profile_dir():
-    """Existing profile dir should still be returned as-is."""
-    with tempfile.TemporaryDirectory() as td:
-        base = Path(td) / ".hermes"
-        base.mkdir(parents=True)
-        profile_dir = base / "profiles" / "ayan"
+        # Create an existing profile directory
+        profile_dir = fake_home / "profiles" / "ayan"
         profile_dir.mkdir(parents=True)
 
-        profiles = _reload_profiles_module(base)
-        result = profiles.get_hermes_home_for_profile("ayan")
-
+        result = get_hermes_home_for_profile("ayan")
         assert result == profile_dir
 
+    def test_nonexistent_profile_still_returns_profile_path(self, _patch_default_home):
+        """Core bug fix: profile dir doesn't exist yet but should still route there."""
+        fake_home, _ = _patch_default_home
+        from api.profiles import get_hermes_home_for_profile
 
-def test_default_profile_routes_to_default_home():
-    """'default' profile should always route to _DEFAULT_HERMES_HOME."""
-    with tempfile.TemporaryDirectory() as td:
-        base = Path(td) / ".hermes"
-        base.mkdir(parents=True)
+        # Do NOT create the profile directory
+        expected = fake_home / "profiles" / "newprofile"
+        assert not expected.exists()  # confirm it doesn't exist
 
-        profiles = _reload_profiles_module(base)
-        result = profiles.get_hermes_home_for_profile("default")
+        result = get_hermes_home_for_profile("newprofile")
+        assert result == expected, "Should route to profile path even when dir missing"
 
-        assert result == base
+    def test_none_returns_default(self, _patch_default_home):
+        fake_home, _ = _patch_default_home
+        from api.profiles import get_hermes_home_for_profile
 
+        result = get_hermes_home_for_profile(None)
+        assert result == fake_home
 
-def test_none_empty_profile_routes_to_default_home():
-    """None / empty profile should route to default home."""
-    with tempfile.TemporaryDirectory() as td:
-        base = Path(td) / ".hermes"
-        base.mkdir(parents=True)
+    def test_empty_string_returns_default(self, _patch_default_home):
+        fake_home, _ = _patch_default_home
+        from api.profiles import get_hermes_home_for_profile
 
-        profiles = _reload_profiles_module(base)
+        result = get_hermes_home_for_profile("")
+        assert result == fake_home
 
-        for name in [None, "", "default"]:
-            result = profiles.get_hermes_home_for_profile(name)
-            assert result == base, f"Profile {name!r} should route to default home"
+    def test_default_string_returns_default(self, _patch_default_home):
+        fake_home, _ = _patch_default_home
+        from api.profiles import get_hermes_home_for_profile
 
-
-def test_path_traversal_still_rejected():
-    """Path traversal attempts must still be rejected (security regression guard)."""
-    with tempfile.TemporaryDirectory() as td:
-        base = Path(td) / ".hermes"
-        base.mkdir(parents=True)
-
-        profiles = _reload_profiles_module(base)
-
-        for malicious in ["../../etc", "../..", "%2e%2e/etc"]:
-            result = profiles.get_hermes_home_for_profile(malicious)
-            assert result == base, (
-                f"Path traversal {malicious!r} should be rejected and fallback to default"
-            )
+        result = get_hermes_home_for_profile("default")
+        assert result == fake_home