test: add RDC_DATA_DIR seam and centralize unit/e2e home isolation

src/rdc/_platform.py

@@ -30,7 +30,14 @@ def join_cmdline(args: list[str]) -> str:
 
 
 def data_dir() -> Path:
-    """Return the per-user data directory for rdc."""
+    """Return the per-user data directory for rdc.
+
+    Honours the ``RDC_DATA_DIR`` environment override (mirrors ``RDC_SESSION``);
+    when unset, falls back to the per-user home-based default.
+    """
+    override = os.environ.get("RDC_DATA_DIR")
+    if override:
+        return Path(override)
     if _WIN:
         base = os.environ.get("LOCALAPPDATA", str(Path.home()))
         return Path(base) / "rdc"

tests/e2e/conftest.py

@@ -6,12 +6,14 @@
 
 from __future__ import annotations
 
+import json
 import logging
 import os
 import uuid
 from collections.abc import Generator
 from pathlib import Path
 
+import e2e_helpers
 import pytest
 from e2e_helpers import (
     DYNAMIC_RENDERING,
@@ -25,6 +27,8 @@
     self_capture,
 )
 
+from rdc import _platform
+
 # ---------------------------------------------------------------------------
 # Session-scoped fixtures
 # ---------------------------------------------------------------------------
@@ -33,6 +37,37 @@
 _DISCOVER_SESSION = "e2e_discover"
 
 
+def _reap_daemons(data_dir: Path) -> None:
+    """Terminate any daemons still recorded under *data_dir* (best effort)."""
+    for session_file in data_dir.glob("sessions/*.json"):
+        try:
+            pid = int(json.loads(session_file.read_text()).get("pid", 0))
+        except (OSError, ValueError, TypeError, json.JSONDecodeError):
+            continue
+        if pid > 0 and _platform.is_pid_alive(pid):
+            _platform.terminate_process_tree(pid)
+
+
+@pytest.fixture(scope="session", autouse=True)
+def _isolate_e2e_data_dir(
+    tmp_path_factory: pytest.TempPathFactory,
+) -> Generator[Path, None, None]:
+    """Redirect every e2e CLI subprocess to a session-scoped tmp data dir.
+
+    Sets ``RDC_DATA_DIR`` for all ``rdc`` subprocesses so the real CLI never
+    writes the developer's ~/.rdc, and reaps any surviving daemons on teardown.
+    Scope is session (not function): an e2e daemon is shared across a module's
+    tests, so per-test isolation would tear shared sessions down mid-run.
+    """
+    data_dir = tmp_path_factory.mktemp("e2e_data") / ".rdc"
+    e2e_helpers.SUBPROCESS_ENV["RDC_DATA_DIR"] = str(data_dir)
+    try:
+        yield data_dir
+    finally:
+        _reap_daemons(data_dir)
+        e2e_helpers.SUBPROCESS_ENV.pop("RDC_DATA_DIR", None)
+
+
 @pytest.fixture(scope="session")
 def captured_rdc(tmp_path_factory: pytest.TempPathFactory) -> Generator[Path, None, None]:
     """Self-capture vkcube or fall back to pre-recorded fixture."""
@@ -56,10 +91,9 @@ def captured_rdc(tmp_path_factory: pytest.TempPathFactory) -> Generator[Path, No
 def capture_meta(captured_rdc: Path) -> CaptureMetadata:
     """Open capture, discover all IDs dynamically, close session."""
     session = f"{_DISCOVER_SESSION}_{uuid.uuid4().hex[:8]}"
-    r = rdc("open", str(captured_rdc), session=session)
-    assert r.returncode == 0, f"Failed to open capture for discovery: {r.stderr}"
-
     try:
+        r = rdc("open", str(captured_rdc), session=session)
+        assert r.returncode == 0, f"Failed to open capture for discovery: {r.stderr}"
         return _discover_metadata(session)
     finally:
         rdc("close", session=session)
@@ -71,8 +105,10 @@ def can_replay_prerecorded() -> bool:
     if not VKCUBE.exists():
         return False
     name = f"e2e_probe_{uuid.uuid4().hex[:8]}"
-    r = rdc("open", str(VKCUBE), session=name)
-    rdc("close", session=name)
+    try:
+        r = rdc("open", str(VKCUBE), session=name)
+    finally:
+        rdc("close", session=name)
     return r.returncode == 0
 
 
@@ -212,10 +248,12 @@ def _discover_metadata(session: str) -> CaptureMetadata:
 def vkcube_session(captured_rdc: Path) -> Generator[str, None, None]:
     """Open captured .rdc and yield session name; close on teardown."""
     name = f"e2e_vkcube_{uuid.uuid4().hex[:8]}"
-    r = rdc("open", str(captured_rdc), session=name)
-    assert r.returncode == 0, f"Failed to open capture: {r.stderr}"
-    yield name
-    rdc("close", session=name)
+    try:
+        r = rdc("open", str(captured_rdc), session=name)
+        assert r.returncode == 0, f"Failed to open capture: {r.stderr}"
+        yield name
+    finally:
+        rdc("close", session=name)
 
 
 @pytest.fixture(scope="module")
@@ -230,8 +268,10 @@ def dynamic_session() -> Generator[str, None, None]:
     r = rdc("open", str(DYNAMIC_RENDERING), session=name)
     if r.returncode != 0:
         pytest.skip(f"dynamic_rendering.rdc failed to open (GPU mismatch?): {r.stderr}")
-    yield name
-    rdc("close", session=name)
+    try:
+        yield name
+    finally:
+        rdc("close", session=name)
 
 
 @pytest.fixture(scope="module")
@@ -246,8 +286,10 @@ def oit_session() -> Generator[str, None, None]:
     r = rdc("open", str(OIT_DEPTH_PEELING), session=name)
     if r.returncode != 0:
         pytest.skip(f"oit_depth_peeling.rdc failed to open (GPU mismatch?): {r.stderr}")
-    yield name
-    rdc("close", session=name)
+    try:
+        yield name
+    finally:
+        rdc("close", session=name)
 
 
 @pytest.fixture(scope="session")

tests/e2e/e2e_helpers.py

@@ -50,6 +50,16 @@ class CaptureMetadata:
 
 VKCUBE_BIN: str | None = os.environ.get("VKCUBE_BIN") or shutil.which("vkcube")
 
+# Extra environment merged into every CLI subprocess. The session-scoped
+# isolation fixture in conftest.py populates this with ``RDC_DATA_DIR`` so the
+# real CLI never touches the developer's ~/.rdc or leaks live daemons.
+SUBPROCESS_ENV: dict[str, str] = {}
+
+
+def _subprocess_env() -> dict[str, str]:
+    """Return the full environment for a CLI subprocess (os.environ + overrides)."""
+    return {**os.environ, **SUBPROCESS_ENV}
+
 
 def self_capture(vkcube_path: str, output: Path, timeout: int = 60) -> Path:
     """Run ``rdc capture`` against *vkcube_path* and return the .rdc path."""
@@ -58,6 +68,7 @@ def self_capture(vkcube_path: str, output: Path, timeout: int = 60) -> Path:
         capture_output=True,
         text=True,
         timeout=timeout,
+        env=_subprocess_env(),
     )
     if r.returncode != 0:
         raise RuntimeError(f"self_capture failed (exit {r.returncode}):\n{r.stderr}")
@@ -84,6 +95,7 @@ def rdc(
         capture_output=True,
         text=True,
         timeout=timeout,
+        env=_subprocess_env(),
     )
 
 

tests/unit/conftest.py

@@ -13,6 +13,19 @@
 from rdc.daemon_server import DaemonState
 
 
+@pytest.fixture(autouse=True)
+def _isolate_data_dir(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    """Isolate every unit test's rdc data dir to a per-test tmp directory.
+
+    Sets ``RDC_DATA_DIR`` (so any subprocess inherits the override) and patches
+    ``rdc._platform.data_dir`` (so in-process callers resolve the same path),
+    guaranteeing tests never read or write the developer's real ``~/.rdc``.
+    """
+    data = tmp_path / ".rdc"
+    monkeypatch.setenv("RDC_DATA_DIR", str(data))
+    monkeypatch.setattr("rdc._platform.data_dir", lambda: data)
+
+
 def rpc_request(
     method: str,
     params: dict[str, Any] | None = None,

tests/unit/test_android_commands.py

@@ -32,11 +32,6 @@
 )
 
 
-@pytest.fixture(autouse=True)
-def _isolate_home(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
-    monkeypatch.setattr("rdc._platform.data_dir", lambda: tmp_path / ".rdc")
-
-
 def _mock_rd_android(
     monkeypatch: pytest.MonkeyPatch,
     devices: list[str] | None = None,

tests/unit/test_capture_control.py

@@ -3,7 +3,6 @@
 from __future__ import annotations
 
 import time
-from pathlib import Path
 from typing import Any
 from unittest.mock import MagicMock
 
@@ -19,11 +18,6 @@
 from rdc.target_state import TargetControlState, save_target_state
 
 
-@pytest.fixture(autouse=True)
-def _isolate_home(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
-    monkeypatch.setattr("rdc._platform.data_dir", lambda: tmp_path / ".rdc")
-
-
 def _make_mock_tc(
     *,
     connected: bool = True,

tests/unit/test_cli_session_flag.py

@@ -77,7 +77,6 @@ def fake_status() -> tuple[bool, object]:
 def test_two_sessions_isolated(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
     """Two named sessions return independent data from their respective files."""
     monkeypatch.setenv("HOME", str(tmp_path))
-    monkeypatch.setattr("rdc._platform.data_dir", lambda: tmp_path / ".rdc")
     monkeypatch.delenv("RDC_SESSION", raising=False)
     monkeypatch.setattr("rdc.services.session_service._renderdoc_available", lambda: False)
     mock_proc = MagicMock()

tests/unit/test_keep_remote.py

@@ -2,7 +2,6 @@
 
 from __future__ import annotations
 
-from pathlib import Path
 from typing import Any
 from unittest.mock import MagicMock
 
@@ -14,11 +13,6 @@
 from rdc.remote_state import RemoteServerState, save_remote_state
 
 
-@pytest.fixture(autouse=True)
-def _isolate_home(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
-    monkeypatch.setattr("rdc._platform.data_dir", lambda: tmp_path / ".rdc")
-
-
 def _save_state() -> None:
     save_remote_state(RemoteServerState(host="192.168.1.10", port=39920, connected_at=1000.0))
 

tests/unit/test_platform.py

@@ -34,16 +34,77 @@
 
 class TestDataDir:
     def test_returns_home_dot_rdc(self, monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
-        """TP-W1-001: Unix data_dir is ~/.rdc."""
+        """TP-W1-001: Unix data_dir is ~/.rdc when no override is set."""
+        monkeypatch.delenv("RDC_DATA_DIR", raising=False)
         monkeypatch.setattr("rdc._platform.Path.home", staticmethod(lambda: tmp_path))
         assert data_dir() == tmp_path / ".rdc"
 
     def test_no_side_effects(self, monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
         """TP-W1-002: data_dir does not create the directory."""
+        monkeypatch.delenv("RDC_DATA_DIR", raising=False)
         monkeypatch.setattr("rdc._platform.Path.home", staticmethod(lambda: tmp_path))
         result = data_dir()
         assert not result.exists()
 
+    def test_env_override_returns_custom_dir(
+        self, monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+    ) -> None:
+        """RDC_DATA_DIR override wins over the home-based default."""
+        custom = tmp_path / "custom-data"
+        monkeypatch.setenv("RDC_DATA_DIR", str(custom))
+        # Even with a different home, the override must take precedence.
+        monkeypatch.setattr("rdc._platform.Path.home", staticmethod(lambda: tmp_path / "elsewhere"))
+        assert data_dir() == custom
+
+    def test_env_override_ignored_when_empty(
+        self, monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+    ) -> None:
+        """An empty RDC_DATA_DIR falls back to the home-based default."""
+        monkeypatch.setenv("RDC_DATA_DIR", "")
+        monkeypatch.setattr("rdc._platform.Path.home", staticmethod(lambda: tmp_path))
+        assert data_dir() == tmp_path / ".rdc"
+
+    def test_env_override_isolates_session_roundtrip(
+        self, monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+    ) -> None:
+        """With RDC_DATA_DIR set, a session save/load round-trip writes nothing under home.
+
+        Regression: prior to the override seam, session_state always resolved
+        ``Path.home()/.rdc`` with no way to redirect a subprocess; this asserts
+        the override fully redirects both the write and the read.
+        """
+        from rdc.session_state import SessionState, load_session, save_session
+
+        fake_home = tmp_path / "home"
+        fake_home.mkdir()
+        data = tmp_path / "isolated"
+        # Restore the genuine data_dir so the env seam (not the conftest patch)
+        # is what redirects session_state's reads and writes.
+        monkeypatch.setattr("rdc._platform.data_dir", data_dir)
+        monkeypatch.setenv("RDC_DATA_DIR", str(data))
+        monkeypatch.setattr("rdc._platform.Path.home", staticmethod(lambda: fake_home))
+        monkeypatch.delenv("RDC_SESSION", raising=False)
+
+        state = SessionState(
+            capture="/tmp/x.rdc",
+            current_eid=7,
+            opened_at="2026-01-01T00:00:00+00:00",
+            host="127.0.0.1",
+            port=4321,
+            token="tok",
+            pid=4242,
+        )
+        save_session(state)
+
+        loaded = load_session()
+        assert loaded is not None
+        assert loaded.capture == "/tmp/x.rdc"
+        assert loaded.current_eid == 7
+        assert (data / "sessions" / "default.json").exists()
+        # Nothing must have leaked under the faked home directory.
+        assert not list(fake_home.rglob("*.json"))
+        assert not (fake_home / ".rdc").exists()
+
 
 # ── Group B: terminate_process() ─────────────────────────────────────
 

tests/unit/test_remote_commands.py

@@ -22,11 +22,6 @@
 from rdc.remote_state import RemoteServerState, save_remote_state
 
 
-@pytest.fixture(autouse=True)
-def _isolate_home(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
-    monkeypatch.setattr("rdc._platform.data_dir", lambda: tmp_path / ".rdc")
-
-
 def _mock_rd(monkeypatch: pytest.MonkeyPatch) -> MagicMock:
     """Provide a mock renderdoc module and patch find_renderdoc."""
     rd = MagicMock()

tests/unit/test_remote_core.py

@@ -119,8 +119,12 @@ def test_parsed_localhost_keys_on_ipv4(self) -> None:
         host, port = parse_url("localhost:39920")
         assert (host, port) == ("127.0.0.1", 39920)
         path = _state_path(host, port)
+        # The state-file key must use the normalized IPv4, never "localhost".
+        # (Assert on the relative key, not the absolute path, since the isolated
+        # data dir lives under a per-test tmp directory whose name may itself
+        # contain "localhost".)
         assert path.name == "127.0.0.1_39920.json"
-        assert "localhost" not in str(path)
+        assert "localhost" not in path.parent.name
 
 
 class TestWarnIfPublic:

tests/unit/test_remote_setup.py

@@ -4,7 +4,6 @@
 
 import json
 import socket
-from pathlib import Path
 from typing import Any
 from unittest.mock import MagicMock
 
@@ -19,11 +18,6 @@
 )
 
 
-@pytest.fixture(autouse=True)
-def _isolate_home(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
-    monkeypatch.setattr("rdc._platform.data_dir", lambda: tmp_path / ".rdc")
-
-
 def _stderr_spy(monkeypatch: pytest.MonkeyPatch) -> list[str]:
     lines: list[str] = []
     orig = click.echo

tests/unit/test_remote_state.py

@@ -18,11 +18,6 @@
 _SAMPLE = RemoteServerState(host="192.168.1.10", port=39920, connected_at=1700000000.0)
 
 
-@pytest.fixture(autouse=True)
-def _isolate_home(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
-    monkeypatch.setattr("rdc._platform.data_dir", lambda: tmp_path / ".rdc")
-
-
 def test_save_and_load_round_trip() -> None:
     save_remote_state(_SAMPLE)
     loaded = load_remote_state("192.168.1.10", 39920)