Update Ableton MIDI exporter and add comprehensive test suite

tests/pattern-events.test.ts

@@ -1,6 +1,7 @@
 import assert from 'node:assert/strict';
 import test from 'node:test';
-import { parsePatternEvents } from '../src/lib/parsers';
+import { collectScenesAndPatterns, parsePatternEvents } from '../src/lib/parsers';
+import { TarFile } from '../src/lib/untar';
 
 function buildPattern(records: number[][], bars: number = 4, declaredCount = records.length) {
   const data = new Uint8Array(4 + records.length * 8);
@@ -56,18 +57,18 @@ test('parses and normalizes fader records', () => {
 });
 
 test('preserves MIDI and unknown records', () => {
-  const midi = [1, 0, (4 << 3) | 2, 0xd0, 75, 3, 4, 5];
+  const midi = [0x27, 0, (2 << 3) | 2, 0xd0, 0x62, 0xff, 0, 0x3d];
   const unknown = [2, 0, (5 << 3) | 6, 10, 11, 12, 13, 14];
   const result = parsePatternEvents(buildPattern([midi, unknown]));
 
   assert.deepEqual(result.events[0], {
     type: 'midi',
     kind: 2,
-    position: 1,
-    source: 4,
-    flags: 5,
+    position: 0x27,
+    source: 2,
+    flags: 0x3d,
     rawData: new Uint8Array(midi),
-    data: new Uint8Array([0xd0, 75, 3, 4]),
+    data: new Uint8Array([0xd0, 0x62, 0xff, 0]),
   });
   assert.deepEqual(result.events[1], {
     type: 'unknown',
@@ -80,6 +81,20 @@ test('preserves MIDI and unknown records', () => {
   });
 });
 
+test('retains MIDI-only sources as empty-note scene patterns', () => {
+  const patternData = buildPattern([[0x27, 0, (2 << 3) | 2, 0xd0, 0x62, 0xff, 0, 0x3d]]);
+  const scenes = collectScenesAndPatterns(
+    [new TarFile('patterns/a01', patternData.length, patternData)],
+    'TE032AS001',
+  );
+
+  assert.equal(scenes.length, 1);
+  assert.equal(scenes[0].patterns.length, 1);
+  assert.equal(scenes[0].patterns[0].pad, 'a2');
+  assert.deepEqual(scenes[0].patterns[0].notes, []);
+  assert.equal(scenes[0].patternEvents.a?.events.length, 1);
+});
+
 test('uses the uint16 header count and ignores undeclared or partial records', () => {
   const records = Array.from({ length: 300 }, (_, index) => [
     index & 0xff,