pax bf14466382 Add Phase A test suite for core/ primitives
First regression-test layer for booru-viewer. Pure Python — no Qt, no
mpv, no network, no real filesystem outside tmp_path. Locks in the
security and concurrency invariants from the 54ccc40 + eb58d76 hardening
commits ahead of the upcoming popout state machine refactor (Prompt 3),
which needs a stable baseline to refactor against.

16 tests across five files mirroring the source layout under
booru_viewer/core/:

- tests/core/test_db.py (4):
  - _validate_folder_name rejection rules (.., /foo, \\foo, .hidden,
    ~user, empty) and acceptance categories (unicode, spaces, parens)
  - add_bookmark INSERT OR IGNORE collision returns the existing row
    id (locks in the lastrowid=0 fix)
  - get_bookmarks LIKE escaping (literal cat_ear does not match catear)

- tests/core/test_cache.py (7):
  - _referer_for hostname suffix matching (gelbooru.com / donmai.us
    apex rewrite, both exact-match and subdomain)
  - _referer_for rejects substring attackers
    (imgblahgelbooru.attacker.com does NOT pick up the booru referer)
  - ugoira frame-count and uncompressed-size caps refuse zip bombs
    before any decompression
  - _do_download MAX_DOWNLOAD_BYTES enforced both at the
    Content-Length pre-check AND in the chunk-loop running total
  - _is_valid_media returns True on OSError (no delete + redownload
    loop on transient EBUSY)

- tests/core/test_config.py (2):
  - saved_folder_dir rejects literal .. and ../escape
  - find_library_files walks root + 1 level, filters by
    MEDIA_EXTENSIONS, exact post-id stem match

- tests/core/test_concurrency.py (2):
  - get_app_loop raises RuntimeError before set_app_loop is called
  - run_on_app_loop round-trips a coroutine result from a worker
    thread loop back to the test thread

- tests/core/api/test_base.py (1):
  - BooruClient._shared_client lazy singleton constructor-once under
    10-thread first-call race

Plus tests/conftest.py with fixtures: tmp_db, tmp_library,
reset_app_loop, reset_shared_clients. All fixtures use tmp_path or
reset module-level globals around the test so the suite is parallel-
safe.

pyproject.toml:
- New [project.optional-dependencies] test extra: pytest>=8.0,
  pytest-asyncio>=0.23
- New [tool.pytest.ini_options]: asyncio_mode = "auto",
  testpaths = ["tests"]

README.md:
- Linux install section gains "Run tests" with the
  pip install -e ".[test]" + pytest tests/ invocation

Phase B (post-sweep VideoPlayer regression tests for the seek slider
pin, _pending_mute lazy replay, and volume replay) is deferred to
Prompt 3's state machine work — VideoPlayer cannot be instantiated
without QApplication and a real mpv, which is out of scope for a
unit test suite. Once the state machine carves the pure-Python state
out of VideoPlayer, those tests become trivial against the helper
module.

Suite runs in 0.07s (16 tests). Independent of Qt/mpv/network/ffmpeg.

Test cases for Prompt 3:
- (already covered) — this IS the test suite Prompt 3 builds on top of
2026-04-08 18:50:00 -05:00
..