# Test Workspace Paths — Hard Rule

## TL;DR

Test workspaces live in the project tree under `tests/artifacts/`. Conftest creates them. No env vars. No CLI args. No `tmp_path_factory`. No `%TEMP%`. No runner changes. **The user must be able to find every test workspace by looking in `tests/artifacts/`.**

## The Rule

When creating a test workspace, fixture, or scratch directory for any test infrastructure:

```python
# CORRECT — conftest creates the path
from datetime import datetime
_RUN_ID = datetime.now().strftime("%Y%m%d_%H%M%S")
_RUN_WORKSPACE = Path(f"tests/artifacts/live_gui_workspace_{_RUN_ID}")

@pytest.fixture(scope="session")
def live_gui(request):
    temp_workspace = _RUN_WORKSPACE
    ...
```

```python
# WRONG — env vars
import os
WORKSPACE = os.environ.get("LIVE_GUI_WORKSPACE", "tests/artifacts/live_gui_workspace")

# WRONG — CLI args
def pytest_addoption(parser):
    parser.addoption("--workspace", action="store", default="tests/artifacts/live_gui_workspace")

# WRONG — tmp_path_factory (lives in %TEMP%, not in project tree)
def live_gui(request, tmp_path_factory):
    temp_workspace = tmp_path_factory.mktemp("live_gui_workspace")
    # Creates: C:\Users\<user>\AppData\Local\Temp\pytest-of-<user>\pytest-N\live_gui_workspace0
    # User CANNOT FIND THIS from the project tree.
```

## Why This Rule Exists

This rule was added 2026-06-09 after a 4-day agent churn on workspace paths. The chain of decisions:

1. Original conftest: `temp_workspace = Path("tests/artifacts/live_gui_workspace")`. Sims worked. User could find the workspace. **This was correct.**

2. Phase 3 of test_infrastructure_hardening_20260609: agent changed it to `tmp_path_factory.mktemp("live_gui_workspace")`. The user did not catch this for 2 days. It moved the workspace to `%TEMP%/pytest-of-<user>/...` which:
   - The user cannot find from the project tree
   - The sims (which compute `os.path.abspath("tests/artifacts/...")` from the project root) could not find the workspace either
   - Caused `test_extended_sims.py::test_context_sim_live` to fail with "stale ui - ops disabled" because the sim's project path didn't match the controller's active_project_path
   - The agent then spent 2 more days trying to fix the sim timing, the MMA state, the RAG state, the watchdog — none of which were the actual cause

3. The user caught the regression. Their feedback: "we should be using a folder in `./tests/`" — i.e., the project tree, not the system temp dir.

4. The agent tried `Path("tests/artifacts/live_gui_workspace")` (no timestamp). That solved the sim issue but was per-session, not per-run. Per-test pollution is desirable (it exposes fragility), so per-run isolation is what we want.

5. The user pushed back on adding CLI args: "have conftest make it, conftest is the right place." The agent then tried env vars as an indirection layer.

6. The user rejected env vars: "env vars are hidden global state, pass it to conftest directly." Conftest is the source of truth.

7. Final solution: conftest creates a per-run timestamped folder under `tests/artifacts/`. One source of truth. No indirection. The user must be able to find every test workspace by looking in `tests/artifacts/`.

## Forbidden Patterns (Hard Bans)

### 1. `tmp_path_factory` for test infrastructure workspaces

`tmp_path_factory` is for pytest's own test isolation (e.g., when a unit test needs a temp dir to write a file). It is **NOT** for test infrastructure workspaces (e.g., the `live_gui` subprocess's CWD). Why:

- `tmp_path_factory` lives in `%TEMP%/pytest-of-<user>/...` — outside the project tree
- The user cannot find the workspace by looking in the project tree
- Any code that uses `os.path.abspath("tests/artifacts/...")` from the project root cannot find the workspace
- The 4 sim tests in `simulation/sim_base.py` are exactly such code

**Use `tmp_path` or `tmp_path_factory` ONLY for:**
- Unit tests that need a temp file/dir
- Test data fixtures that don't outlive the test
- Any case where the path is consumed only by the test itself, not by a subprocess

**Do NOT use for:**
- The `live_gui` subprocess CWD
- Any workspace that a long-running subprocess (GUI, server) operates on
- Any path that other code computes via `os.path.abspath("tests/...")` from the project root

### 2. Environment variables for test paths

Env vars are hidden global state. The user has explicitly banned them. They are also a host for the "I'll just check the env var" anti-pattern, which is what bad coders do.

**Do NOT use `os.environ` for:**
- Test workspace paths
- Test configuration that could be a conftest constant
- Anything that the conftest can compute itself

### 3. CLI args for test paths

The conftest is the right place. CLI args add a layer of indirection between the runner and the test, and they require the runner to be modified to pass them. The user has explicitly rejected this.

**Do NOT add `--workspace=PATH` or similar CLI args.** If you need a path, compute it in conftest.

## The Correct Pattern

```python
# tests/conftest.py

from datetime import datetime
from pathlib import Path

# Module-level constants, computed once at conftest import time.
# Per-pytest-invocation isolation: each `uv run pytest` gets a new folder.
# Per-test pollution is INTENTIONAL (exposes fragility).
_RUN_ID = datetime.now().strftime("%Y%m%d_%H%M%S")
_RUN_WORKSPACE = Path(f"tests/artifacts/live_gui_workspace_{_RUN_ID}")

@pytest.fixture(scope="session")
def live_gui(request) -> Generator["_LiveGuiHandle", None, None]:
    temp_workspace = _RUN_WORKSPACE
    # ... use temp_workspace
```

## What Lives in `tests/artifacts/`

Everything test-related that needs to be on disk:

- `tests/artifacts/live_gui_workspace_<timestamp>/` — per-run live_gui workspace (this rule)
- `tests/artifacts/manualslop_layout_default.ini` — read-only default layout
- `tests/artifacts/*.log` — test logs
- `tests/artifacts/post_*_batch_*.log` — batch run logs

All of these are gitignored via the existing `tests/artifacts/` entry in `.gitignore`.

## Verification

```bash
# The workspace must be in the project tree:
$ ls tests/artifacts/ | grep live_gui_workspace
live_gui_workspace_20260609_201530

# It must be gitignored:
$ git check-ignore tests/artifacts/live_gui_workspace_20260609_201530
tests/artifacts/live_gui_workspace_20260609_201530
```

## Audit

`scripts/check_test_toml_paths.py` already flags `Path("C:/projects/")` and other hardcoded paths. Add a check for `tmp_path_factory.mktemp` and `os.environ.get.*WORKSPACE` in production-style conftest changes. (This is a follow-up task, not a hard requirement.)

## See Also

- `conductor/workflow.md` §"Process Anti-Patterns" #9 (this rule, added 2026-06-09)
- `conductor/tracks/workspace_path_finalize_20260609/` — the track that established this rule
- `docs/reports/rag_test_batch_failure_status_20260609_pm3.md` — the audit findings that led to the rule
- `conductor/code_styleguides/test_sandbox.md` — the 4-layer sandbox enforcement model (extends this rule with the `--config` CLI flag + Layer 1 audit hook; added 2026-06-19 per `test_sandbox_hardening_20260619`)
