hermes - 💡(How to fix) Fix gateway/mirror.py has no test coverage despite being production code

Problem

gateway/mirror.py is a production module with 4 public functions (mirror_to_session, _find_session_id, _append_to_jsonl, _append_to_sqlite) that writes mirrored messages to both JSONL and SQLite backends. It has zero test coverage — no unit tests or integration tests reference it.

Expected Outcome

All functions in gateway/mirror.py have unit tests covering normal paths and error paths (missing session, JSONL write failure, SQLite write failure).

Suggested Approach

Create tests/gateway/test_mirror.py with:

• test_mirror_to_session_jsonl — verify JSONL append on a known session
• test_mirror_to_session_sqlite — verify SQLite insert on a known session
• test_mirror_to_session_unknown_session — _find_session_id returns None, function handles gracefully
• test_append_jsonl_creates_dir — JSONL append creates parent dir if missing
• test_append_sqlite_creates_db — SQLite append creates DB file if missing

Suggested Files

• gateway/mirror.py (source)
• tests/gateway/test_mirror.py (new test file)