# Cross-Code Review Report: B-9 (LOGS_DIR import-time cwd freeze fix)

- **Job ID**: c35385ad
- **Reviewer**: cline
- **Date**: 2026-08-17
- **Backlog Item**: B-9 (P4-1) — `LOGS_DIR` import-time cwd freeze resolution
- **Changed Files**: `mqtt_common.py`, `registry.py`, `registry.md`, `tests/test_tier1_unit.py`, `IMPROVEMENTS.md`, `VERSIONS.md`

---

## 1. Objective

Verify that the B-9 implementation correctly refactors `mqtt_common.py` and `registry.py` to resolve the audit-log root (`LOGS_DIR`) dynamically at call time via `get_logs_dir()`, eliminating the import-time `os.getcwd()` freeze that caused audit-log path drift after `chdir`. Backward compatibility for `mqtt_common.LOGS_DIR` consumers must be preserved, 5 dedicated regression tests must be added, and documentation must be accurate.

---

## 2. Implementation Review

### 2.1 `mqtt_common.py` — Core Fix

**Before:**
```python
def _default_logs_dir() -> str: ...
LOGS_DIR = _default_logs_dir()      # frozen at import time
```

**After:**
```python
def get_logs_dir() -> str:
    """Audit-log root, resolved at call time (B-9). ..."""
    env = os.environ.get("DELEGATE_JOB_LOGS_DIR")
    if env and env.strip():
        return env
    return os.path.join(os.getcwd(), ".mam", "delegate_job_logs")

def __getattr__(name: str):          # PEP 562 (3.7+)
    if name == "LOGS_DIR":
        return get_logs_dir()
    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")

def __dir__():
    return sorted(set(globals()) | {"LOGS_DIR"})
```

**Assessment:**
- The module-level `LOGS_DIR = _default_logs_dir()` assignment is **removed** — verified by AST guard test and manual grep (0 hits at module scope).
- `get_logs_dir()` is now **public** (renamed from `_default_logs_dir`), resolving the path per call.
- PEP 562 `__getattr__` provides backward-compatible `mqtt_common.LOGS_DIR` access, resolving dynamically each time.
- PEP 562 `__dir__` keeps `LOGS_DIR` discoverable in `dir()` and tab-completion.
- `__getattr__` correctly raises `AttributeError` for unknown attributes (prevents infinite recursion in `hasattr`).

**Internal callers updated (all resolve through `get_logs_dir()` when `logs_dir=None`):**
| Function | Line | Pattern |
|---|---|---|
| `job_log_dir` | 441 | `Path(logs_dir or get_logs_dir()) / job_id` |
| `job_log_path` | 444 | delegates to `job_log_dir` |
| `append_event` | 488 | delegates to `job_log_path` |
| `init_job_log` | 523 | delegates to `job_log_dir` |
| `update_logged_status` | 505 | delegates to `job_log_path` |
| `read_logged_meta` | 553 | delegates to `job_log_path` |
| `read_logged_status` | 561 | delegates to `job_log_path` |
| `iter_logged_events` | 572 | delegates to `job_log_path` |
| `list_logged_jobs` | 589 | `Path(logs_dir or get_logs_dir())` |

All 9 audit-log functions chain through `get_logs_dir()` when no explicit `logs_dir` is passed. **No stale `or LOGS_DIR` (bare global) references remain.**

### 2.2 `registry.py` — Consumer Updates

Two references updated from `mqtt_common.LOGS_DIR` to `mqtt_common.get_logs_dir()`:
- Line 198 (`get_feedback`): `logs_dir = mqtt_common.get_logs_dir()` ✓
- Line 389 (`_cmd_logs`): `logs_dir = args.logs_dir or mqtt_common.get_logs_dir()` ✓

### 2.3 `registry.md` — Documentation

Helper list updated to describe `get_logs_dir` as the primary API with `LOGS_DIR` noted as a "dynamic compat alias". Accurate and consistent with the implementation.

### 2.4 Backward Compatibility

- `from mqtt_common import LOGS_DIR` — **0 occurrences** in the entire repository (verified by grep). Compat surface 100% covered by `__getattr__`.
- `mqtt_common.LOGS_DIR` attribute access — preserved via PEP 562 `__getattr__`, resolves dynamically.
- `DELEGATE_JOB_LOGS_DIR` env override — now reflected at call time (bonus improvement, not a regression).

### 2.5 Test Suite (`tests/test_tier1_unit.py`)

5 new B-9 regression tests (lines 406–473):

| Test | Guard Type | What It Verifies |
|---|---|---|
| `test_b9_logs_dir_follows_cwd_changes` | T1 (dynamic) | `get_logs_dir()` and `LOGS_DIR` compat alias follow `chdir` |
| `test_b9_audit_log_lands_under_the_current_cwd` | T3 (file creation) | Actual `meta.json` file appears under current cwd (catches swallowed errors) |
| `test_b9_logs_dir_env_override_is_dynamic` | Env dynamic | `DELEGATE_JOB_LOGS_DIR` honored at call time; clearing restores cwd default |
| `test_b9_no_module_level_logs_dir_binding` | T1 (AST static) | No module-level `LOGS_DIR` assignment (covers `Assign` and `AnnAssign`) |
| `test_b9_logs_dir_stays_discoverable` | C2-a (PEP 562) | `LOGS_DIR` in `dir()`, `hasattr` works, no duplicates |

The T3 guard is particularly well-designed — it asserts the **actual file** appears on disk, not just string equality. This is critical because the audit-log layer uses best-effort `except Exception` that swallows errors silently.

### 2.6 Documentation (`IMPROVEMENTS.md`, `VERSIONS.md`)

**IMPROVEMENTS.md:** Header updated (date, 276/276, 24 completed, 1 open). B-9 moved to completed section (lines 84–90). Edge-case section shows "0건 — 전원 완료". ✓

---

## 3. Verification Results

### 3.1 Syntax Checks (`py_compile`)
| File | Result |
|---|---|
| `mqtt_common.py` | ✅ PASS |
| `registry.py` | ✅ PASS |
| `tests/test_tier1_unit.py` | ✅ PASS |

### 3.2 Stale Reference Scan
| Check | Result |
|---|---|
| `from mqtt_common import LOGS_DIR` in source | ✅ 0 occurrences |
| Bare `or LOGS_DIR` (global) in source | ✅ 0 occurrences |
| Module-level `LOGS_DIR =` assignment | ✅ 0 occurrences (removed) |

### 3.3 B-9 Targeted Tests
```
tests/test_tier1_unit.py::test_b9_logs_dir_follows_cwd_changes PASSED    [ 20%]
tests/test_tier1_unit.py::test_b9_audit_log_lands_under_the_current_cwd PASSED [ 40%]
tests/test_tier1_unit.py::test_b9_logs_dir_env_override_is_dynamic PASSED [ 60%]
tests/test_tier1_unit.py::test_b9_no_module_level_logs_dir_binding PASSED [ 80%]
tests/test_tier1_unit.py::test_b9_logs_dir_stays_discoverable PASSED     [100%]
5 passed, 30 deselected in 0.10s
```

### 3.4 Full Test Suite
```
276 passed in 422.40s (0:07:02)
```
**Zero failures, zero errors, zero regressions.** Test count increased from 271 → 276 (+5 new B-9 tests), consistent with documentation claims.

---

## 4. Lint & Quality Assessment

- **No unused imports** introduced by the change.
- **No dead code** — `__getattr__` and `__dir__` are both exercised by tests.
- **PEP 562** is the idiomatic Python ≥3.7 pattern for dynamic module attributes; test environment runs Python 3.9.6.
- **Thread safety**: `get_logs_dir()` calls `os.environ.get()` and `os.getcwd()`, both thread-safe in CPython. Per-call overhead is negligible vs. the file I/O it precedes.
- **No surgical-change violations**: every changed line traces directly to the B-9 requirement.

---

## 5. Concerns & Observations

1. **Minor (non-blocking):** `__dir__` returns `sorted(set(globals()) | {"LOGS_DIR"})` — `LOGS_DIR` would still appear in `dir()` even if `__getattr__` were removed. Purely cosmetic; the AST guard test catches actual binding regressions.
2. **No escalation needed:** The fix is a clean, surgical refactor. No design-level rework required.

---

## 6. Verdict

The B-9 implementation is **correct, complete, and well-tested**:
- The import-time cwd freeze is eliminated — `get_logs_dir()` resolves per call.
- Backward compatibility is fully preserved via PEP 562 `__getattr__`/`__dir__`.
- All internal callers and external consumers (`registry.py`) are updated.
- 5 high-quality regression tests guard against regression (AST static guard + file-creation guard).
- Documentation (`IMPROVEMENTS.md`, `VERSIONS.md`, `registry.md`) is accurate.
- Full test suite: **276/276 PASS**, zero regressions.

[VERDICT: PASS]