feat: daybreak finale turns the contact arrival into a sunrise with a dawn chord

tests/unit/dawn-resolve.test.ts

@@ -0,0 +1,88 @@
+import { describe, expect, it } from 'vitest';
+import {
+  createDawnResolve,
+  DAWN_CHORD_HZ,
+  DAWN_DETUNE_CENTS,
+  DAWN_OPEN_SECONDS,
+  DAWN_PAD_GAIN,
+  DAWN_RELEASE_SECONDS,
+  DAWN_SWELL_SECONDS,
+} from '@/audio/dawn-resolve';
+import { createFakeAudioHarness, type FakeAudioHarness } from '../helpers/fake-audio-context';
+
+const events = (harness: FakeAudioHarness) => harness.params.flatMap((record) => record.events);
+
+describe('dawn resolve', () => {
+  it('preallocates a silent four-note pad, each note a +/-4 cent pair, plus one breath source', () => {
+    const harness = createFakeAudioHarness();
+    createDawnResolve(harness.context, harness.destination);
+    const oscillators = harness.sources.filter((record) => record.kind === 'oscillator');
+    const buffers = harness.sources.filter((record) => record.kind === 'buffer');
+    expect(oscillators).toHaveLength(DAWN_CHORD_HZ.length * 2);
+    expect(buffers).toHaveLength(1);
+    const notes = oscillators.map((record) => {
+      const node = record.node as OscillatorNode;
+      return [node.frequency.value, node.detune.value];
+    });
+    for (const frequency of [110, 164.8, 220, 329.6]) {
+      expect(notes).toContainEqual([frequency, -DAWN_DETUNE_CENTS]);
+      expect(notes).toContainEqual([frequency, DAWN_DETUNE_CENTS]);
+    }
+    for (const source of harness.sources) expect(source.starts).toHaveLength(1);
+    // Silent until arrival: no ramp is scheduled at construction.
+    expect(events(harness).filter((event) => event.kind === 'linear' || event.kind === 'exponential'))
+      .toEqual([]);
+  });
+
+  it('swells in over 5 s while the low-pass opens 900 -> 2600 Hz over 6 s, without new nodes', () => {
+    const harness = createFakeAudioHarness();
+    const dawn = createDawnResolve(harness.context, harness.destination);
+    const sourceCount = harness.sources.length;
+    const gainCount = harness.gainNodes.length;
+    harness.setCurrentTime(10);
+    dawn.setDawn(true);
+    const scheduled = events(harness);
+    expect(scheduled).toContainEqual({ kind: 'linear', value: DAWN_PAD_GAIN, at: 10 + DAWN_SWELL_SECONDS });
+    expect(scheduled).toContainEqual({ kind: 'exponential', value: 2_600, at: 10 + DAWN_OPEN_SECONDS });
+    expect(DAWN_PAD_GAIN).toBe(0.09);
+    expect(harness.sources).toHaveLength(sourceCount);
+    expect(harness.gainNodes).toHaveLength(gainCount);
+  });
+
+  it('releases over 1.6 s when driving away and ignores repeated states', () => {
+    const harness = createFakeAudioHarness();
+    const dawn = createDawnResolve(harness.context, harness.destination);
+    dawn.setDawn(false);
+    expect(events(harness).filter((event) => event.kind === 'linear')).toEqual([]);
+    harness.setCurrentTime(1);
+    dawn.setDawn(true);
+    const afterOn = events(harness).length;
+    dawn.setDawn(true);
+    expect(events(harness)).toHaveLength(afterOn);
+    harness.setCurrentTime(4);
+    dawn.setDawn(false);
+    // Events are grouped per parameter, so pick the release out by its start time.
+    const release = events(harness).filter((event) => event.at >= 4);
+    expect(release).toContainEqual({ kind: 'linear', value: 0, at: 4 + DAWN_RELEASE_SECONDS });
+    expect(release).toContainEqual({ kind: 'exponential', value: 900, at: 4 + DAWN_RELEASE_SECONDS });
+    // Every ramp holds its parameter first, so a release mid-swell never jumps.
+    expect(release.filter((event) => event.kind === 'hold' && event.at === 4)).toHaveLength(4);
+  });
+
+  it('stops and disconnects every source exactly once and goes quiet after dispose', () => {
+    const harness = createFakeAudioHarness();
+    const dawn = createDawnResolve(harness.context, harness.destination);
+    dawn.dispose();
+    dawn.dispose();
+    for (const source of harness.sources) {
+      expect(source.stops).toHaveLength(1);
+      expect(source.disconnectCount).toBe(1);
+    }
+    for (const node of harness.gainNodes) {
+      expect((node as GainNode & { disconnectCount: number }).disconnectCount).toBe(1);
+    }
+    const before = events(harness).length;
+    dawn.setDawn(true);
+    expect(events(harness)).toHaveLength(before);
+  });
+});