feat: thêm soundfont và VSTi cho MIDI

tests/test_vst_engine.py

@@ -0,0 +1,95 @@
+import os
+import json
+import pytest
+import numpy as np
+from unittest.mock import patch, MagicMock
+
+from app.core.vst_engine import PluginManager, midi_note_to_freq, render_midi_events_to_audio, HAS_PEDALBOARD
+
+
+class TestPluginManager:
+    def test_init(self):
+        pm = PluginManager()
+        assert pm.vst_dir == "/opt/daw_engine/vst3"
+        assert pm.sf_dir == "/opt/daw_engine/soundfonts"
+
+    def test_midi_events_to_messages(self):
+        if not HAS_PEDALBOARD:
+            pytest.skip("pedalboard not available")
+        events = [{"note": 60, "start_beat": 0, "duration_beats": 1, "velocity": 100}]
+        bpm = 120
+        sr = 44100
+        msgs = PluginManager.midi_events_to_messages(events, bpm, sr)
+        beat_sec = 60.0 / 120
+        expected_note_on_offset = 0
+        expected_note_off_offset = int(beat_sec * sr)
+        # Check note_on message
+        assert msgs[0].sample_offset == expected_note_on_offset
+        assert msgs[0].note == 60
+        # Check note_off message
+        assert msgs[1].sample_offset == expected_note_off_offset
+        assert msgs[1].note == 60
+
+    def test_list_available_empty(self):
+        pm = PluginManager(vst_dir="/tmp/nonexistent_vst_dir_xyz", sf_dir="/tmp/nonexistent_sf_dir_xyz")
+        available = pm.list_available()
+        assert "vst_instruments" in available
+        assert "soundfonts" in available
+        assert available["vst_instruments"] == []
+        assert available["soundfonts"] == []
+
+    def test_validate_sf2_header_valid(self):
+        # Valid RIFF + sfbk header
+        valid = b'RIFF' + b'\x00' * 4 + b'sfbk' + b'\x00' * 100
+        assert PluginManager.validate_sf2_header(valid) is True
+
+    def test_validate_sf2_header_invalid_no_riff(self):
+        invalid = b'XXXX' + b'\x00' * 4 + b'sfbk' + b'\x00' * 100
+        assert PluginManager.validate_sf2_header(invalid) is False
+
+    def test_validate_sf2_header_invalid_no_sfbk(self):
+        invalid = b'RIFF' + b'\x00' * 4 + b'XXXX' + b'\x00' * 100
+        assert PluginManager.validate_sf2_header(invalid) is False
+
+    def test_validate_sf2_header_too_short(self):
+        assert PluginManager.validate_sf2_header(b'RIFF') is False
+
+
+class TestMidiNoteToFreq:
+    def test_a4_440(self):
+        assert midi_note_to_freq(69) == 440.0
+
+    def test_c4(self):
+        # C4 = MIDI 60 = 261.63
+        freq = midi_note_to_freq(60)
+        assert abs(freq - 261.63) < 0.5
+
+    def test_note_zero_to_freq(self):
+        freq = midi_note_to_freq(0)
+        assert freq > 0 and freq < 10
+
+
+class TestRenderMidiToAudio:
+    def test_render_single_note(self):
+        events = [{"note": 60, "start_beat": 0, "duration_beats": 1, "velocity": 100}]
+        audio = render_midi_events_to_audio(events, sr=44100, bpm=120)
+        assert audio.shape[0] == 2  # Stereo
+        assert audio.shape[1] > 0
+        # Should have non-zero samples
+        assert np.max(np.abs(audio)) > 0
+
+    def test_render_empty_events(self):
+        audio = render_midi_events_to_audio([], sr=44100, bpm=120)
+        assert audio.shape[0] == 2  # Stereo
+        # Empty events defaults to 2 seconds of silence (minimum length)
+        assert audio.shape[1] >= 0
+
+    def test_render_multiple_notes(self):
+        events = [
+            {"note": 60, "start_beat": 0, "duration_beats": 1, "velocity": 100},
+            {"note": 64, "start_beat": 1, "duration_beats": 1, "velocity": 80},
+            {"note": 67, "start_beat": 2, "duration_beats": 1, "velocity": 90},
+        ]
+        audio = render_midi_events_to_audio(events, sr=44100, bpm=120)
+        assert audio.shape[0] == 2
+        assert audio.shape[1] > 44100 * 1