test: isolate state-dir probes from user state

Author: pxxD1998

tests/test_issue4449_state_dir_contract.py

@@ -12,27 +12,35 @@
 
 from __future__ import annotations
 
+import json
 import os
 import subprocess
 import sys
 from pathlib import Path
 
 REPO_ROOT = Path(__file__).resolve().parents[1]
 
-_PROBE = (
-    "import api.config as c; "
-    "print(c.STATE_DIR)"
-)
+_PROBE = "import api.config as c; print(c.STATE_DIR)"
 
 
-def _state_dir_for_env(**env_overrides) -> Path:
+def _state_dir_for_env(platform_home: Path, **env_overrides) -> Path:
     """Import api.config in a fresh subprocess under the given env and return
     the resolved STATE_DIR it computes. None-valued overrides unset the var."""
     env = dict(os.environ)
-    # Start from a clean slate for the two vars under test so the parent
-    # process's pytest values don't bleed in.
+    # Keep every probe inside fixture-owned platform paths. Inheriting the real
+    # user home lets an import-only probe reconcile pytest workspace defaults
+    # into the user's settings.json before it prints STATE_DIR.
+    env["HOME"] = str(platform_home)
+    env["USERPROFILE"] = str(platform_home)
+    env["LOCALAPPDATA"] = str(platform_home / "AppData" / "Local")
+    # Start from a clean slate for the vars that can redirect state or trigger
+    # startup settings reconciliation in the child process.
     env.pop("HERMES_HOME", None)
+    env.pop("HERMES_BASE_HOME", None)
     env.pop("HERMES_WEBUI_STATE_DIR", None)
+    env.pop("HERMES_WEBUI_TEST_STATE_DIR", None)
+    env.pop("HERMES_WEBUI_DEFAULT_WORKSPACE", None)
+    env.pop("HERMES_CONFIG_PATH", None)
     for key, value in env_overrides.items():
         if value is None:
             env.pop(key, None)
@@ -50,33 +58,66 @@ def _state_dir_for_env(**env_overrides) -> Path:
     return Path(out.stdout.strip()).resolve()
 
 
-def _platform_default_state_dir() -> Path:
+def _platform_default_state_dir(platform_home: Path) -> Path:
     """What STATE_DIR resolves to with HERMES_HOME + STATE_DIR both unset."""
-    return _state_dir_for_env()
+    return _state_dir_for_env(platform_home)
+
+
+def test_state_dir_probe_does_not_mutate_platform_default_settings(
+    tmp_path, monkeypatch
+):
+    """The subprocess probe must not reconcile pytest defaults into user state."""
+    platform_home = tmp_path / "platform-home"
+    if os.name == "nt":
+        settings_file = (
+            platform_home / "AppData" / "Local" / "hermes" / "webui" / "settings.json"
+        )
+    else:
+        settings_file = platform_home / ".hermes" / "webui" / "settings.json"
+    settings_file.parent.mkdir(parents=True)
+    persisted_workspace = tmp_path / "persisted-workspace"
+    persisted_workspace.mkdir()
+    original = (
+        json.dumps({"default_workspace": str(persisted_workspace)}) + "\n"
+    ).encode()
+    settings_file.write_bytes(original)
+
+    monkeypatch.setenv("HOME", str(platform_home))
+    monkeypatch.setenv("USERPROFILE", str(platform_home))
+    monkeypatch.setenv(
+        "HERMES_WEBUI_DEFAULT_WORKSPACE", str(tmp_path / "pytest-workspace")
+    )
+
+    state_dir = _platform_default_state_dir(platform_home)
+
+    assert settings_file.read_bytes() == original
+    assert state_dir == settings_file.parent.resolve()
 
 
 def test_config_state_dir_defaults_to_hermes_home_webui(tmp_path):
     hermes_home = tmp_path / ".hermes" / "profiles" / "isolated"
     hermes_home.mkdir(parents=True)
 
-    state_dir = _state_dir_for_env(HERMES_HOME=hermes_home)
+    state_dir = _state_dir_for_env(tmp_path / "platform-home", HERMES_HOME=hermes_home)
     assert state_dir == (hermes_home / "webui").resolve()
 
 
-def test_config_state_dir_unchanged_for_normal_install_hermes_home_unset():
+def test_config_state_dir_unchanged_for_normal_install_hermes_home_unset(tmp_path):
     """Backward-compat: with HERMES_HOME unset, STATE_DIR stays at the platform
     default `<~/.hermes>/webui` — a normal install's state must NOT relocate
     (the #4449/#4454 state-dir move only affects an explicitly-set HERMES_HOME).
 
     Cross-check: the unset-HERMES_HOME result must NOT equal the result of
     pointing HERMES_HOME at an arbitrary other base — i.e. the default is
     genuinely the platform home, not whatever the test environment injected."""
-    default = _platform_default_state_dir()
+    platform_home = tmp_path / "platform-home"
+    default = _platform_default_state_dir(platform_home)
     assert default.name == "webui"
     # Pointing HERMES_HOME elsewhere produces a DIFFERENT dir, proving the unset
     # case resolves to the platform default rather than echoing an injected base.
-    elsewhere = _state_dir_for_env(HERMES_HOME="/tmp/hermes-4449-elsewhere-base")
-    assert elsewhere == Path("/tmp/hermes-4449-elsewhere-base/webui").resolve()
+    elsewhere_base = tmp_path / "elsewhere-base"
+    elsewhere = _state_dir_for_env(platform_home, HERMES_HOME=elsewhere_base)
+    assert elsewhere == (elsewhere_base / "webui").resolve()
     assert default != elsewhere
 
 
@@ -88,6 +129,7 @@ def test_config_state_dir_explicit_override_takes_precedence(tmp_path):
     explicit = tmp_path / "custom-state"
 
     state_dir = _state_dir_for_env(
+        tmp_path / "platform-home",
         HERMES_HOME=hermes_home,
         HERMES_WEBUI_STATE_DIR=explicit,
     )