"""Tests for the cross-Hermes-profile write guard in agent/file_safety. The guard fires when a tool tries to write into another Hermes profile's skills/plugins/cron/memories directory. It's a soft guard — defense in depth, NOT a security boundary — but it prevents the agent from silently corrupting a profile that belongs to a different session. Reference: May 2026 incident — a hermes-security profile session accidentally edited skills under both ~/.hermes/profiles/hermes-security/skills/ AND ~/.hermes/skills/ (the default profile's skills), realizing only afterwards that the second path belonged to a different profile. """ from __future__ import annotations from pathlib import Path import pytest # --------------------------------------------------------------------------- # Helpers — set up a fake Hermes root with two profiles, monkeypatch the # resolver helpers so the classifier sees the test layout. # --------------------------------------------------------------------------- @pytest.fixture def fake_hermes(tmp_path, monkeypatch): """Build a fake Hermes layout: / skills/foo/SKILL.md # default profile plugins/foo/__init__.py cron/ memories/MEMORY.md profiles/ hermes-security/ skills/foo/SKILL.md # named profile plugins/... coder/ skills/foo/SKILL.md # another named profile """ root = tmp_path / "fake-hermes" (root / "skills" / "foo").mkdir(parents=True) (root / "skills" / "foo" / "SKILL.md").write_text("# default skill\n") (root / "plugins" / "foo").mkdir(parents=True) (root / "memories").mkdir(parents=True) (root / "cron").mkdir(parents=True) sec_home = root / "profiles" / "hermes-security" (sec_home / "skills" / "foo").mkdir(parents=True) (sec_home / "skills" / "foo" / "SKILL.md").write_text("# sec skill\n") (sec_home / "plugins").mkdir(parents=True) coder_home = root / "profiles" / "coder" (coder_home / "skills" / "foo").mkdir(parents=True) (coder_home / "skills" / "foo" / "SKILL.md").write_text("# coder skill\n") # Monkeypatch the resolver functions used by file_safety so each test # can choose which profile is "active". import hermes_constants monkeypatch.setattr(hermes_constants, "get_default_hermes_root", lambda: root) # The reloads below ensure get_cross_profile_warning/classify see the patched root. import agent.file_safety as fs monkeypatch.setattr(fs, "_hermes_root_path", lambda: root) return { "root": root, "default_home": root, "security_home": sec_home, "coder_home": coder_home, } def _set_active_home(monkeypatch, hermes_home: Path): """Point file_safety._hermes_home_path at a specific profile dir.""" import agent.file_safety as fs monkeypatch.setattr(fs, "_hermes_home_path", lambda: hermes_home) # --------------------------------------------------------------------------- # _resolve_active_profile_name # --------------------------------------------------------------------------- class TestResolveActiveProfileName: def test_default_when_home_is_root(self, fake_hermes, monkeypatch): _set_active_home(monkeypatch, fake_hermes["default_home"]) from agent.file_safety import _resolve_active_profile_name assert _resolve_active_profile_name() == "default" def test_falls_back_to_default_on_resolution_failure(self, fake_hermes, monkeypatch): """If HERMES_HOME resolution raises, return 'default' rather than crashing the tool.""" import agent.file_safety as fs def _boom(): raise RuntimeError("simulated") monkeypatch.setattr(fs, "_hermes_home_path", _boom) # Should not raise — falls back to "default" assert fs._resolve_active_profile_name() == "default" # --------------------------------------------------------------------------- # classify_cross_profile_target # --------------------------------------------------------------------------- class TestClassifyCrossProfileTarget: def test_security_writing_default_skill(self, fake_hermes, monkeypatch): """The exact incident from May 2026.""" _set_active_home(monkeypatch, fake_hermes["security_home"]) from agent.file_safety import classify_cross_profile_target result = classify_cross_profile_target( str(fake_hermes["default_home"] / "skills" / "foo" / "SKILL.md") ) assert result is not None assert result["active_profile"] == "hermes-security" assert result["target_profile"] == "default" assert result["area"] == "skills" def test_default_writing_security_skill(self, fake_hermes, monkeypatch): """Inverse direction — default-profile session reaching into a named profile.""" _set_active_home(monkeypatch, fake_hermes["default_home"]) from agent.file_safety import classify_cross_profile_target result = classify_cross_profile_target( str(fake_hermes["security_home"] / "skills" / "foo" / "SKILL.md") ) assert result is not None assert result["active_profile"] == "default" assert result["target_profile"] == "hermes-security" @pytest.mark.parametrize("area", ["skills", "plugins", "cron", "memories"]) def test_all_profile_scoped_areas_classified(self, fake_hermes, monkeypatch, area): _set_active_home(monkeypatch, fake_hermes["security_home"]) from agent.file_safety import classify_cross_profile_target target = fake_hermes["default_home"] / area / "foo.txt" result = classify_cross_profile_target(str(target)) assert result is not None assert result["area"] == area # --------------------------------------------------------------------------- # get_cross_profile_warning # --------------------------------------------------------------------------- class TestGetCrossProfileWarning: """The guard is RETIRED (maintainer decision): profiles are not isolated, so the warning helper is a permanent None stub — kept only so external callers fail soft. The classifier itself survives for the system-prompt hint and diagnostics.""" def test_in_profile_returns_none(self, fake_hermes, monkeypatch): from agent.file_safety import get_cross_profile_warning assert get_cross_profile_warning( str(fake_hermes["root"] / "skills" / "a" / "SKILL.md")) is None def test_cross_profile_returns_none_guard_retired(self, fake_hermes, monkeypatch): from agent.file_safety import get_cross_profile_warning target = fake_hermes["root"] / "profiles" / "security" / "skills" / "x" / "SKILL.md" assert get_cross_profile_warning(str(target)) is None