test: update bit-depth guard tests to the unified quality-guard behavior

check_flac_bit_depth now delegates to check_quality_target, which probes the
real file and treats bit depth as a MINIMUM (24-bit satisfies a 16-bit
target) — the old context-string parsing, per-quality bit_depth_fallback, and
'reject higher bit depth' semantics are gone. Rewrite the wrapper tests to
the probe-based model and update the rejection-reason assertion to the
unified 'quality filter' wording.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/imports/test_import_guards.py

@@ -1,47 +1,55 @@
+"""``check_flac_bit_depth`` is a thin legacy wrapper that delegates to the
+unified ``check_quality_target`` guard, which probes the REAL file (mutagen)
+and ranks it against the v3 ranked-targets list.
+
+The old per-quality ``bit_depth_fallback`` config and the "reject a higher bit
+depth" semantics are gone by design: bit depth is now a MINIMUM, so a 24-bit
+file satisfies a 16-bit target. These tests pin the wrapper's current
+behaviour (deeper coverage of ``check_quality_target`` lives in
+``tests/imports/test_quality_guard.py``).
+"""
+
 from types import SimpleNamespace
 
-from core.imports import guards
+import core.imports.guards as guards
+import core.imports.file_ops as file_ops
+from core.quality.model import AudioQuality
 
 
 class _FakeDB:
-    def __init__(self, quality_profile):
-        self._quality_profile = quality_profile
+    def __init__(self, profile):
+        self._profile = profile
 
     def get_quality_profile(self):
-        return self._quality_profile
+        return self._profile
 
 
-def test_check_flac_bit_depth_rejects_strict_mismatch(monkeypatch):
+_WANT_FLAC24 = {
+    "fallback_enabled": False,
+    "ranked_targets": [
+        {"label": "FLAC 24-bit/96kHz", "format": "flac", "bit_depth": 24, "min_sample_rate": 96000},
+    ],
+}
+
+
+def _patch(monkeypatch, aq, profile):
+    monkeypatch.setattr(file_ops, "probe_audio_quality", lambda fp: aq)
+    monkeypatch.setattr(guards, "MusicDatabase", lambda: _FakeDB(profile))
     monkeypatch.setattr(
-        guards,
-        "MusicDatabase",
-        lambda: _FakeDB({"qualities": {"flac": {"bit_depth": "16", "bit_depth_fallback": False}}}),
-    )
-    monkeypatch.setattr(
-        guards,
-        "_get_config_manager",
+        guards, "_get_config_manager",
         lambda: SimpleNamespace(get=lambda _key, default=None: False),
     )
 
-    context = {"_audio_quality": "FLAC 24bit", "track_info": {"name": "Song One"}}
 
-    assert guards.check_flac_bit_depth("/tmp/Song One.flac", context) == (
-        "FLAC bit depth mismatch: file is 24-bit, preference is 16-bit"
-    )
+def test_check_flac_bit_depth_rejects_below_target(monkeypatch):
+    # 16-bit file, target wants 24-bit, fallback off → rejected.
+    _patch(monkeypatch, AudioQuality("flac", sample_rate=44100, bit_depth=16), _WANT_FLAC24)
+    reason = guards.check_flac_bit_depth("/tmp/Song One.flac", {})
+    assert reason is not None
+    assert "FLAC 24-bit/96kHz" in reason
 
 
-def test_check_flac_bit_depth_allows_fallback_when_enabled(monkeypatch):
-    monkeypatch.setattr(
-        guards,
-        "MusicDatabase",
-        lambda: _FakeDB({"qualities": {"flac": {"bit_depth": "16", "bit_depth_fallback": True}}}),
-    )
-    monkeypatch.setattr(
-        guards,
-        "_get_config_manager",
-        lambda: SimpleNamespace(get=lambda _key, default=None: False),
-    )
-
-    context = {"_audio_quality": "FLAC 24bit", "track_info": {"name": "Song One"}}
-
-    assert guards.check_flac_bit_depth("/tmp/Song One.flac", context) is None
+def test_check_flac_bit_depth_accepts_when_meeting_target(monkeypatch):
+    # 24-bit/96k file meets the 24-bit target → accepted.
+    _patch(monkeypatch, AudioQuality("flac", sample_rate=96000, bit_depth=24), _WANT_FLAC24)
+    assert guards.check_flac_bit_depth("/tmp/Song One.flac", {}) is None

tests/imports/test_import_rejection_reason.py

@@ -48,9 +48,11 @@ def test_acoustid_quarantine_without_message_still_flags():
 
 
 def test_bitdepth_rejection_detected():
+    # The _bitdepth_rejected flag now signals any quality-target rejection
+    # (bit depth, sample rate, format, bitrate) — the unified quality guard.
     reason = import_rejection_reason({'_bitdepth_rejected': True})
     assert reason is not None
-    assert 'bit-depth' in reason.lower()
+    assert 'quality filter' in reason.lower()
 
 
 def test_race_guard_failure_detected():