soulsync/tests/test_tidal_stream_tier_verification.py
Broque Thomas a9f827ef42 Reject Tidal streams that silently downgrade from the requested quality
Reported on Discord by Netti93: with Tidal configured for "HiRes only"
and "Allow Quality Fallback" disabled, tracks were still downloading
successfully — as m4a 320kbps files. Some "successful" downloads were
less than half the file size of the same track pulled via Tidarr/tiddl
from the same Tidal account.

Root cause: Tidal's API silently degrades to the best quality your
account + the track + your region permits. Setting
`session.audio_quality = Quality.hi_res_lossless` and calling
`track.get_stream()` on a track that's only available in AAC returns
an AAC stream with no error. The downloader wrote the m4a file to
disk, the ~7MB size sailed past the 100KB stub threshold, and the
download reported success.

The pre-existing "verify quality wasn't silently downgraded" block
only LOGGED a warning when this happened; it did not fail the tier.
Two knock-on effects:

- Users with "HiRes only, no fallback" got m4a files anyway, which
  defeats the setting entirely.
- The worker-level fallback chain (hires → lossless → high → low)
  couldn't advance past the first tier, because every tier
  "succeeded" at whatever Tidal happened to serve.

Fix: after `track.get_stream()`, compare `stream.audio_quality`
against the tier we asked for using a rank-based ordering:

    LOW < HIGH < LOSSLESS < HI_RES < HI_RES_LOSSLESS

- Same tier or higher → accept (so the occasional Tidal upgrade
  doesn't get rejected just because it's not an exact match).
- Lower tier → reject THIS tier. The loop `continue`s and the next
  fallback tier is tried, or the whole download fails honestly
  when the user has fallback disabled. The existing final-error
  log already has a hint directing users to enable fallback if
  they want automatic Lossless substitution.
- Unrecognized `audioQuality` value (e.g. a new Tidal tier we
  haven't mapped) → reject conservatively, so the next fallback
  tier gets a chance and the diagnostic log names the unknown
  value.

Why the rank-based approach instead of strict equality:

Tidal's API doesn't technically promise an exact-tier match on
serving; on tracks that are flagged in its catalog as a higher
tier, it can serve higher than the session setting. Rejecting
higher-than-asked quality would be user-hostile. And the `HI_RES`
(legacy MQA) value — not in tidalapi's modern `Quality` enum but
possibly still present on old catalog entries — needs to rank
below `HI_RES_LOSSLESS`: users asking for true lossless HiRes
should reject MQA since MQA is a lossy format.

tidalapi's `Quality` enum is a `str` subclass whose VALUES (not
member names) match what the Tidal API returns in the
`audioQuality` field (e.g. `Quality.hi_res_lossless.value ==
'HI_RES_LOSSLESS'`, `Quality.low_320k.value == 'HIGH'`). Both
sides of the comparison are coerced to `str` before use, so the
check is robust to whichever tidalapi version exposes the served
quality as an enum or a plain string.

The check is extracted as `_verify_stream_tier(stream, q_info,
q_key) -> (ok, reason)` at module scope — a pure function with no
I/O, unit-tested independently. Ten tests: match, three upgrade
cases (LOSSLESS → HI_RES_LOSSLESS, LOSSLESS → HI_RES, LOW → any
higher), three downgrade cases (the reported HiRes → AAC, HiRes
Lossless → MQA HiRes, Lossless → AAC), one unrecognized-tier case,
and two defensive paths for older tidalapi builds without
`audio_quality` on the stream object and for QUALITY_MAP entries
that lack `tidal_quality` (e.g. tidalapi wasn't importable at
module load). Test stub updated to use uppercase `Quality` values
matching real tidalapi so case-sensitivity regressions get caught.

Also removed the old codec-string-based warning block — the new
tier check is strictly stronger, and keeping the warning around
would just be dead code waiting to drift out of sync.

Deliberately NOT tackling in this PR (documented as follow-ups):

- Bit-depth verification of HiRes FLAC files via mutagen. The
  `stream.audio_quality` tier check catches the main "HiRes
  requested, got AAC" case; bit-depth would only matter if Tidal
  labeled a stream HI_RES_LOSSLESS but served a 16-bit FLAC
  (`Stream.bit_depth` isn't reliable for this — tidalapi defaults
  missing `bitDepth` fields to 16, so a trust-the-stream check
  would spuriously reject valid HiRes whenever Tidal omits the
  field). A proper fix runs mutagen post-download to inspect the
  actual file, then decides whether to delete + retry the next
  tier — a whole new failure mode with design trade-offs that
  deserve their own PR. The support logs don't show this
  happening.

- The "manual remap still says Not Found" symptom. Might be
  downstream of this same bug (silent-AAC "success" hitting a
  later rejection), might be a separate task-state issue. Not
  guessing without logs from the retry path.

- Quality-aware stub threshold. 100KB is a reasonable floor for
  real stub/preview detection and there's no evidence the
  universal threshold is misfiring in the wild.

Field-verified status: desk-verified via unit tests and empirical
checks against a live tidalapi import (confirming the `Quality`
enum's str-subclass behavior). Not yet smoke-tested end-to-end
against a real Tidal account with a HiRes-only-no-fallback
setting — Netti93 or anyone else with that config should notice
either the fix working (non-HiRes tracks fail honestly with a
clear log line) or any regression before wider release.

Files:
- core/tidal_download_client.py — new `_verify_stream_tier` helper
  and `_QUALITY_RANK` table at module scope, called in the
  download loop after the stream is fetched and before any
  bandwidth is spent. Removed the old inline codec-based warning
  since the new check supersedes it.
- tests/test_tidal_stream_tier_verification.py — ten tests covering
  match / upgrade / downgrade / unknown / defensive paths.
- tests/test_tidal_search_shortening.py — fake `Quality` values
  brought in line with tidalapi's real values so both files share
  a consistent stub regardless of pytest collection order.
- webui/static/helper.js — WHATS_NEW entry under 2.40 describing
  the rank-based tier comparison.

Reported on Discord by Netti93 — the "same account works via
Tidarr" comparison narrowed the cause to SoulSync's download path
rather than an account/region issue.
2026-04-24 13:12:30 -07:00

162 lines
6.3 KiB
Python

"""Tests for `_verify_stream_tier` — the guard that rejects silent Tidal
quality downgrades so the fallback chain (or "HiRes only" with fallback
disabled) behaves the way users configure it to.
Without this check, a user with "HiRes only, no quality fallback" who
asks Tidal for a track that's only available in AAC 320kbps would
receive the 320kbps stream silently — Tidal never raises, it just
serves the highest tier available — and the downloader would accept
the m4a file and report success. Reported by Netti93.
Tiers ranked worst-to-best:
LOW < HIGH < LOSSLESS < HI_RES < HI_RES_LOSSLESS
Accepting matches and upgrades, rejecting downgrades, rejecting
unrecognized values.
Note on the fake Quality values: tidalapi's real Quality enum has
VALUES that differ from the member names (e.g., `low_320k.value ==
'HIGH'`, `high_lossless.value == 'LOSSLESS'`). The stub mirrors real
values so the tests catch case-sensitivity regressions.
"""
import sys
import types
if 'tidalapi' not in sys.modules:
_fake = types.ModuleType('tidalapi')
class _FakeQuality:
low_96k = 'LOW'
low_320k = 'HIGH'
high_lossless = 'LOSSLESS'
hi_res = 'HI_RES'
hi_res_lossless = 'HI_RES_LOSSLESS'
_fake.Quality = _FakeQuality
_fake.media = types.SimpleNamespace(Track=object)
sys.modules['tidalapi'] = _fake
from core.tidal_download_client import QUALITY_MAP, _verify_stream_tier # noqa: E402
class _FakeStream:
"""Minimal stand-in for tidalapi.media.Stream."""
def __init__(self, audio_quality=None):
if audio_quality is not None:
self.audio_quality = audio_quality
# ---------------------------------------------------------------------------
# Match — served quality is exactly what was requested
# ---------------------------------------------------------------------------
def test_served_quality_matches_request():
stream = _FakeStream(audio_quality='HI_RES_LOSSLESS')
ok, reason = _verify_stream_tier(stream, QUALITY_MAP['hires'], 'hires')
assert ok is True
assert reason is None
# ---------------------------------------------------------------------------
# Upgrades — Tidal serving a higher tier than requested is accepted
# ---------------------------------------------------------------------------
def test_lossless_request_upgraded_to_hires_is_accepted():
"""If Tidal serves HI_RES_LOSSLESS on a LOSSLESS-tier request (rare
but possible on tracks flagged as such in Tidal's catalog), we take
the upgrade — rejecting a better-than-asked tier would be user-
hostile."""
stream = _FakeStream(audio_quality='HI_RES_LOSSLESS')
ok, reason = _verify_stream_tier(stream, QUALITY_MAP['lossless'], 'lossless')
assert ok is True
assert reason is None
def test_lossless_request_upgraded_to_mqa_hires_is_accepted():
stream = _FakeStream(audio_quality='HI_RES')
ok, reason = _verify_stream_tier(stream, QUALITY_MAP['lossless'], 'lossless')
assert ok is True
assert reason is None
def test_low_request_upgraded_to_any_higher_tier_is_accepted():
stream = _FakeStream(audio_quality='LOSSLESS')
ok, reason = _verify_stream_tier(stream, QUALITY_MAP['low'], 'low')
assert ok is True
assert reason is None
# ---------------------------------------------------------------------------
# Downgrades — the reported bug
# ---------------------------------------------------------------------------
def test_hires_downgraded_to_aac_is_rejected():
"""The exact case Netti93 reported: asked HiRes, Tidal served
AAC 320kbps (`'HIGH'` in Tidal's API vocabulary)."""
stream = _FakeStream(audio_quality='HIGH')
ok, reason = _verify_stream_tier(stream, QUALITY_MAP['hires'], 'hires')
assert ok is False
assert 'HIGH' in reason
assert 'HI_RES_LOSSLESS' in reason
def test_hires_lossless_downgraded_to_mqa_hires_is_rejected():
"""User explicitly asked for HI_RES_LOSSLESS (true lossless HiRes).
Getting MQA-encoded HI_RES is a downgrade even though both are
"HiRes tier" marketing-wise — MQA is lossy."""
stream = _FakeStream(audio_quality='HI_RES')
ok, reason = _verify_stream_tier(stream, QUALITY_MAP['hires'], 'hires')
assert ok is False
assert 'HI_RES_LOSSLESS' in reason
def test_lossless_downgraded_to_aac_is_rejected():
stream = _FakeStream(audio_quality='HIGH')
ok, reason = _verify_stream_tier(stream, QUALITY_MAP['lossless'], 'lossless')
assert ok is False
assert 'LOSSLESS' in reason
# ---------------------------------------------------------------------------
# Unknown quality strings — reject conservatively
# ---------------------------------------------------------------------------
def test_unknown_served_quality_is_rejected():
"""If Tidal introduces a new tier we haven't mapped yet, we can't
prove it's acceptable — reject rather than silently pass through,
so the next fallback tier gets a chance and the final diagnostic
log names the unknown value."""
stream = _FakeStream(audio_quality='SPATIAL_360_DREAM_TIER')
ok, reason = _verify_stream_tier(stream, QUALITY_MAP['hires'], 'hires')
assert ok is False
assert 'SPATIAL_360_DREAM_TIER' in reason
assert 'unrecognized' in reason.lower() or 'can\'t verify' in reason.lower()
# ---------------------------------------------------------------------------
# Defensive — missing attributes must not spuriously fail downloads
# ---------------------------------------------------------------------------
def test_stream_without_audio_quality_attr_is_accepted():
"""Older tidalapi versions may not expose audio_quality — treat as
"can't verify" and let pre-existing codec / file-size guards decide.
Better to miss a downgrade than break every Tidal download after a
library upgrade."""
stream = _FakeStream()
assert not hasattr(stream, 'audio_quality')
ok, reason = _verify_stream_tier(stream, QUALITY_MAP['hires'], 'hires')
assert ok is True
assert reason is None
def test_quality_info_without_tidal_quality_is_accepted():
"""If QUALITY_MAP somehow lacks 'tidal_quality' (tidalapi failed to
import at module load), don't spuriously reject streams."""
stream = _FakeStream(audio_quality='HI_RES_LOSSLESS')
ok, reason = _verify_stream_tier(stream, {'label': 'x'}, 'hires')
assert ok is True
assert reason is None