Clean release snapshot

tests/test_notation_lift.py

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+"""Tests for lib/notation_lift.py — the reusable wire → notation heuristics.
+
+These cover the extracted core directly (independent of the
+scripts/lift_keys_notation.py CLI glue): wire decode, simultaneity grouping,
+hand split, downbeat/tempo derivation, duration quantization, and full
+``build_notation`` assembly including anacrusis and tie-across-barline.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+import notation
+import notation_lift as nl
+
+
+# ── Helpers ──────────────────────────────────────────────────────────────────
+
+def _wire(t: float, midi: int, sus: float = 0.0) -> dict:
+    """Guitar-wire keys note: midi packed as s*24 + f."""
+    return {"t": t, "s": midi // 24, "f": midi % 24, "sus": sus}
+
+
+def _beats_4_4(n_measures: int, bpm: float = 120.0) -> list[dict]:
+    """Song-level downbeats for ``n_measures`` bars of 4/4 at a steady tempo."""
+    secs_per_measure = (4 * 4.0 / 4) * 60.0 / bpm  # 4 quarter notes
+    return [{"time": round(i * secs_per_measure, 6), "measure": i}
+            for i in range(n_measures)]
+
+
+# ── Wire decoding ────────────────────────────────────────────────────────────
+
+def test_decode_wire_notes_unpacks_midi_and_sorts():
+    arr = {"notes": [_wire(1.0, 67, 0.5), _wire(0.0, 60)]}
+    out = nl.decode_wire_notes(arr)
+    assert [n["midi"] for n in out] == [60, 67]
+    assert out[0] == {"t": 0.0, "midi": 60, "sus": 0.0}
+    assert out[1]["sus"] == 0.5
+
+
+def test_decode_wire_notes_includes_chord_notes_at_chord_time():
+    # Chord notes carry no own time → they sound at the chord's t.
+    chord_note = lambda midi: {"s": midi // 24, "f": midi % 24}
+    arr = {"chords": [{"t": 2.0, "notes": [chord_note(60), chord_note(64)]}]}
+    out = nl.decode_wire_notes(arr)
+    assert {n["midi"] for n in out} == {60, 64}
+    assert all(n["t"] == 2.0 for n in out)
+
+
+def test_decode_wire_notes_skips_malformed_and_out_of_range():
+    arr = {"notes": [{"t": "x", "s": 2, "f": 5}, {"t": 0.0, "s": 99, "f": 0}]}
+    assert nl.decode_wire_notes(arr) == []
+
+
+def test_decode_wire_notes_accepts_legacy_l_sustain_alias():
+    out = nl.decode_wire_notes({"notes": [{"t": 0.0, "s": 2, "f": 12, "l": 0.75}]})
+    assert out[0]["sus"] == 0.75
+
+
+# ── Simultaneity grouping ────────────────────────────────────────────────────
+
+def test_group_simultaneous_buckets_within_window():
+    notes = [{"t": 0.0, "midi": 60}, {"t": 0.005, "midi": 64},
+             {"t": 0.5, "midi": 67}]
+    groups = nl.group_simultaneous(notes)
+    assert [len(g) for g in groups] == [2, 1]
+
+
+# ── Hand split ───────────────────────────────────────────────────────────────
+
+def test_split_hands_wide_span_splits_at_largest_gap_low_to_lh():
+    # 36 (C2) ... 72 (C5): span 36 > 12 → split at the largest internal gap.
+    notes = [{"t": 0.0, "midi": 36, "sus": 0}, {"t": 0.0, "midi": 72, "sus": 0}]
+    hands = nl.split_hands(notes)
+    assert hands["lh"][0]["midi"] == 36
+    assert hands["rh"][0]["midi"] == 72
+
+
+def test_split_hands_narrow_group_goes_by_mean_vs_middle_c():
+    low = nl.split_hands([{"t": 0.0, "midi": 48, "sus": 0},
+                          {"t": 0.0, "midi": 52, "sus": 0}])
+    assert "lh" in low and "rh" not in low  # mean 50 < 60
+    high = nl.split_hands([{"t": 0.0, "midi": 64, "sus": 0},
+                           {"t": 0.0, "midi": 67, "sus": 0}])
+    assert "rh" in high and "lh" not in high  # mean ~65.5 ≥ 60
+
+
+# ── Timing ───────────────────────────────────────────────────────────────────
+
+def test_downbeat_times_filters_non_downbeats_and_sorts():
+    beats = [{"time": 2.0, "measure": 1}, {"time": 0.5, "measure": -1},
+             {"time": 0.0, "measure": 0}]
+    assert nl.downbeat_times(beats) == [0.0, 2.0]
+
+
+def test_measure_tempos_from_spacing_and_inherits_last():
+    # 2.0 s per 4/4 bar → 120 BPM; last bar inherits previous.
+    assert nl.measure_tempos([0.0, 2.0, 4.0], (4, 4)) == pytest.approx([120, 120, 120])
+    assert nl.measure_tempos([0.0], (4, 4)) == [120.0]
+
+
+def test_quantize_duration_floors_at_32nd_and_picks_dotted():
+    qn = 60.0 / 120.0  # 0.5 s
+    assert nl.quantize_duration(qn, 120.0) == (4, 0)          # quarter
+    assert nl.quantize_duration(qn * 1.5, 120.0) == (4, 1)    # dotted quarter
+    assert nl.quantize_duration(0.0001, 120.0) == (32, 0)     # floor
+
+
+# ── Full assembly ────────────────────────────────────────────────────────────
+
+def test_build_notation_returns_none_without_notes_or_downbeats():
+    assert nl.build_notation([], _beats_4_4(1)) is None
+    assert nl.build_notation(nl.decode_wire_notes({"notes": [_wire(0, 60)]}), []) is None
+
+
+def test_build_notation_valid_payload_and_staves():
+    notes = nl.decode_wire_notes({"notes": [
+        _wire(0.0, 60, 0.5), _wire(0.0, 48, 0.5),  # both hands, beat 1
+        _wire(0.5, 64, 0.5),
+    ]})
+    payload = nl.build_notation(notes, _beats_4_4(1), instrument="piano")
+    ok, reason = notation.validate_notation(payload)
+    assert ok, reason
+    assert payload["instrument"] == "piano"
+    assert {s["id"] for s in payload["staves"]} == {"rh", "lh"}
+    assert payload["measures"][0]["ts"] == [4, 4]
+
+
+def test_build_notation_marks_pickup_for_anacrusis():
+    # An onset before the first downbeat (downbeat at t=0.5) → pickup measure.
+    beats = [{"time": 0.5, "measure": 0}, {"time": 2.5, "measure": 1}]
+    notes = nl.decode_wire_notes({"notes": [_wire(0.0, 67), _wire(0.5, 72)]})
+    payload = nl.build_notation(notes, beats)
+    assert payload["measures"][0].get("pickup") is True
+
+
+def test_build_notation_ties_note_across_barline():
+    # A whole-bar sustain that starts mid-bar must split into tied continuations.
+    beats = _beats_4_4(2, bpm=120.0)  # 2 s per bar
+    notes = nl.decode_wire_notes({"notes": [_wire(1.0, 48, sus=2.0)]})  # spans bar 1→2
+    payload = nl.build_notation(notes, beats)
+    ok, reason = notation.validate_notation(payload)
+    assert ok, reason
+    # The continuation in measure 2 must be tied (midi 48 → lh).
+    m2 = payload["measures"][1]["staves"]["lh"]["voices"][0]["beats"]
+    assert any(n.get("tied") for b in m2 for n in b["notes"])