ep-133-project-export/tests/ableton-midi.test.ts

import assert from 'node:assert/strict';
import test from 'node:test';
import { buildMidiClipEnvelopes, decodeChannelPressure } from '../src/lib/exporters/ableton/midi';
import abletonTransformer, { AblMidiEvent } from '../src/lib/transformers/ableton';
import {
  EffectType,
  FaderParam,
  Group,
  GroupFaderParam,
  Pad,
  PatternEventKind,
  ProjectRawData,
} from '../src/types/types';

function midiEvent(position: number, source: number, value: number): AblMidiEvent {
  const rawData = new Uint8Array([
    position & 0xff,
    position >> 8,
    (source << 3) | PatternEventKind.Midi,
    0xd0,
    value,
    0xff,
    0,
    0x3d,
  ]);
  return {
    position,
    source,
    flags: rawData[7],
    rawData,
    data: rawData.slice(3, 7),
  };
}

function faderParams(): GroupFaderParam {
  return Object.fromEntries(
    (['a', 'b', 'c', 'd'] as Group[]).map((group) => [
      group,
      Object.fromEntries(Array.from({ length: 12 }, (_, parameter) => [parameter, -1])),
    ]),
  ) as GroupFaderParam;
}

function pad(group: Group, index: number): Pad {
  return {
    pad: index + 1,
    name: `${group}${index}`,
    group,
    file: null,
    rawData: null,
    soundId: 0,
    volume: 100,
    attack: 0,
    release: 0,
    trimLeft: 0,
    trimRight: 0,
    soundLength: 0,
    playMode: 'oneshot',
    pan: 0,
    pitch: 0,
    rootNote: 60,
    timeStretch: 'off',
    timeStretchBpm: 0,
    timeStretchBars: 0,
    inChokeGroup: false,
    midiChannel: 0,
  };
}

test('decodes only the captured EP Channel Pressure record shape', () => {
  assert.equal(decodeChannelPressure(midiEvent(39, 2, 98)), 98);
  assert.equal(
    decodeChannelPressure({ ...midiEvent(39, 2, 98), data: new Uint8Array([0xd0, 98, 3, 4]) }),
    undefined,
  );
  assert.equal(
    decodeChannelPressure({ ...midiEvent(39, 2, 98), data: new Uint8Array([0xb0, 1, 98, 0]) }),
    undefined,
  );
});

test('builds native Live 10 Channel Pressure steps with raw values', () => {
  const controllerTargets = {
    'ControllerTargets.1': { '@Id': 45123, LockEnvelope: { '@Value': 0 } },
  };
  const envelopes = buildMidiClipEnvelopes(
    [midiEvent(192, 2, 20), midiEvent(96, 2, 75), midiEvent(96, 2, 20)],
    controllerTargets,
  );
  const envelope = envelopes[0];
  const events = envelope.Automation.Events.FloatEvent;

  assert.equal(envelope.EnvelopeTarget.PointeeId['@Value'], 45123);
  assert.equal(controllerTargets['ControllerTargets.1'].LockEnvelope['@Value'], 1);
  assert.deepEqual(
    events.map((event: any) => [event['@Time'], event['@Value']]),
    [
      [-63072000, 0],
      [1, 0],
      [1, 75],
      [1, 75],
      [1, 20],
      [2, 20],
    ],
  );
  assert.deepEqual(envelope.LoopSlot, { Value: {} });
});

test('retains an unchanged zero-pressure event at its original time', () => {
  const envelopes = buildMidiClipEnvelopes([midiEvent(48, 2, 0)], {
    'ControllerTargets.1': { '@Id': 45123 },
  });

  assert.deepEqual(
    envelopes[0].Automation.Events.FloatEvent.map((event: any) => [
      event['@Time'],
      event['@Value'],
    ]),
    [
      [-63072000, 0],
      [0.5, 0],
    ],
  );
});

test('routes each source curve only to its matching pad clip, including MIDI-only pads', () => {
  const source0 = midiEvent(24, 0, 30);
  const source1 = midiEvent(48, 1, 60);
  const source2 = midiEvent(72, 2, 90);
  const params = faderParams();
  const events = [source0, source1, source2].map((event) => ({
    type: 'midi' as const,
    kind: PatternEventKind.Midi,
    ...event,
  }));
  const project = {
    pads: {
      a: [pad('a', 0), pad('a', 1), pad('a', 2)],
      b: [],
      c: [],
      d: [],
    },
    scenes: [
      {
        number: 1,
        name: '01',
        patternNumbers: { a: 1, b: 0, c: 0, d: 0 },
        timeSignature: { numerator: 4, denominator: 4 },
        patterns: [
          { pad: 'a0', group: 'a', notes: [], bars: 1 },
          { pad: 'a1', group: 'a', notes: [], bars: 1 },
          { pad: 'a2', group: 'a', notes: [], bars: 1 },
        ],
        patternEvents: {
          a: {
            group: 'a',
            patternNumber: 1,
            bars: 1,
            recordCount: 3,
            events,
          },
        },
      },
    ],
    groupPatterns: [
      {
        group: 'a',
        patternNumber: 1,
        bars: 1,
        recordCount: 3,
        events,
        notes: { 0: [], 1: [], 2: [] },
      },
    ],
    songPositions: [],
    settings: {
      bpm: 120,
      scale: 0,
      rootNote: 0,
      groupFaderParams: params,
      faderAssignment: {
        a: FaderParam.LVL,
        b: FaderParam.LVL,
        c: FaderParam.LVL,
        d: FaderParam.LVL,
      },
      rawData: new Uint8Array(),
    },
    effects: {
      rawData: new Uint8Array(),
      effectType: EffectType.Off,
      param1: 0,
      param2: 0,
    },
    sounds: [],
    projectFile: null as unknown as File,
    scenesSettings: { timeSignature: { numerator: 4, denominator: 4 } },
  } satisfies ProjectRawData;

  const result = abletonTransformer(project, {});

  assert.deepEqual(
    result.tracks.map((track) => [
      track.padCode,
      track.lane?.sessionClips[0].notes.length,
      track.lane?.sessionClips[0].midiEvents.map((event) => event.data[1]),
    ]),
    [
      ['a0', 0, [30]],
      ['a1', 0, [60]],
      ['a2', 0, [90]],
    ],
  );
});