simulator/e2e/tests/music-playlist.spec.ts

@@ -1,57 +1,63 @@
 import { test, expect, Page } from "@playwright/test";
 
-// Music is a rotating playlist that crossfades to a random OTHER track on a timer
-// (docs/music-candidate-pool.md). The e2e injects short rotate/xfade intervals via
-// window.__hefMusicRotateMs / __hefMusicXfadeMs before load.
+// Music is a shuffle: each track plays to its END, then a random OTHER track plays
+// (never an immediate repeat), gaplessly, for as long as Music is selected. The e2e
+// injects a short crossfade via window.__hefMusicXfadeMs and simulates a track finishing
+// by dispatching its "ended" event (real tracks are minutes long).
 
-async function boot(page: Page, rotateMs: number, xfadeMs: number) {
-  await page.addInitScript(([r, x]) => {
-    (window as any).__hefMusicRotateMs = r;
-    (window as any).__hefMusicXfadeMs = x;
-  }, [rotateMs, xfadeMs]);
+const MUSIC_RE = /audio\/music\/(manatees|dewdrop|eastminster|overheat|concentration)\.mp3/;
+
+async function boot(page: Page, xfadeMs = 300) {
+  await page.addInitScript((x) => { (window as any).__hefMusicXfadeMs = x; }, xfadeMs);
   await page.goto("/");
   await page.waitForFunction(() => (window as any).__hefReady === true, null, { timeout: 45_000 });
   await page.locator("#welcome-launch").click();
   await page.waitForSelector("#welcome", { state: "detached", timeout: 10_000 });
 }
 
-// The track on the louder (active) music element.
-async function activeTrack(page: Page): Promise<string> {
+// id ("aud"/"aud-b") of the louder (active) music element, and the track it holds.
+async function active(page: Page): Promise<{ id: string; url: string }> {
   return await page.evaluate(() => {
     const a = document.querySelector("#aud") as HTMLAudioElement;
     const b = document.querySelector("#aud-b") as HTMLAudioElement;
     const el = b.volume > a.volume ? b : a;
-    return el.dataset.url || "";
+    return { id: el.id, url: el.dataset.url || "" };
   });
 }
+// Simulate the active track finishing.
+async function endActive(page: Page, id: string) {
+  await page.evaluate((i) => (document.querySelector("#" + i) as HTMLAudioElement).dispatchEvent(new Event("ended")), id);
+}
 
-test("Music crossfades to a DIFFERENT playlist track after the rotate interval", async ({ page }) => {
-  await boot(page, 1200, 300);
+test("when the current track ends, a new RANDOM track plays", async ({ page }) => {
+  await boot(page);
   await page.selectOption("#audio-source", "music");
   await page.waitForTimeout(200);
-  const first = await activeTrack(page);
-  expect(first).toMatch(/audio\/music\/\w+\.mp3/);
-  // Wait past one rotation (1200ms) + the crossfade (300ms) + buffer.
+  const first = await active(page);
+  expect(first.url).toMatch(MUSIC_RE);
+  await endActive(page, first.id);
   await page.waitForFunction((f) => {
     const a = document.querySelector("#aud") as HTMLAudioElement;
     const b = document.querySelector("#aud-b") as HTMLAudioElement;
     const el = b.volume > a.volume ? b : a;
-    return (el.dataset.url || "") !== f && (el.dataset.url || "").includes("/audio/music/");
-  }, first, { timeout: 6000 });
-  const second = await activeTrack(page);
-  expect(second).toMatch(/audio\/music\/\w+\.mp3/);
-  expect(second).not.toBe(first);          // rotated to another track
+    return (el.dataset.url || "").includes("/audio/music/") && (el.dataset.url || "") !== f;
+  }, first.url, { timeout: 6000 });
+  const second = await active(page);
+  expect(second.url).toMatch(MUSIC_RE);
+  expect(second.url).not.toBe(first.url);   // never an immediate repeat
 });
 
-test("Music keeps rotating (a second rotation lands on a track again)", async ({ page }) => {
-  await boot(page, 900, 250);
+test("Music keeps playing across several track-ends", async ({ page }) => {
+  await boot(page);
   await page.selectOption("#audio-source", "music");
   const seen = new Set<string>();
   for (let i = 0; i < 3; i++) {
-    await page.waitForTimeout(1300);
-    seen.add(await activeTrack(page));
+    await page.waitForTimeout(400);
+    const cur = await active(page);
+    seen.add(cur.url);
+    await endActive(page, cur.id);
+    await page.waitForTimeout(400);          // let the crossfade settle
   }
-  // Over 3 rotations we should have heard more than one distinct track.
-  expect([...seen].every((u) => /audio\/music\/\w+\.mp3/.test(u))).toBe(true);
-  expect(seen.size).toBeGreaterThan(1);
+  expect([...seen].every((u) => MUSIC_RE.test(u))).toBe(true);
+  expect(seen.size).toBeGreaterThan(1);      // it moved through multiple tracks
 });

simulator/static/app.js

@@ -1466,7 +1466,7 @@ function updateAudioStatus() {
 }
 aud.addEventListener("error", updateAudioStatus);
 audB.addEventListener("error", updateAudioStatus);
-setInterval(updateAudioStatus, 400);
+setInterval(() => { updateAudioStatus(); musicWatchdog(); }, 400);
 
 // Cancel any in-flight fade on an element. A fade is a setInterval ramping volume;
 // if a stale one keeps running after a new fade or a direct volume set, it drags the
@@ -1523,20 +1523,22 @@ function soundtrackUrl() { return scaleAudioUrl(ringIndex); }
 
 // --- Music: a rotating playlist of mellow synth tracks that CROSSFADE between each
 // other (not one looping track), altitude-independent — the same relaxing rotation at
-// every altitude. Every MUSIC_ROTATE_MS it crossfades to a random OTHER track (never an
-// immediate repeat), reusing the two audio elements. Intervals are injectable for tests.
+// every altitude. Each track plays to its END, then a random OTHER one plays (never an
+// immediate repeat); a short crossfade a few seconds before the end keeps it GAPLESS, so
+// Music is always playing while selected. Reuses the two audio elements. The crossfade
+// duration is injectable for tests.
 const MUSIC_PLAYLIST = [
   "music/manatees.mp3", "music/dewdrop.mp3", "music/eastminster.mp3",
   "music/overheat.mp3", "music/concentration.mp3",
 ];
-const MUSIC_ROTATE_MS = (typeof window !== "undefined" && window.__hefMusicRotateMs) || 5 * 60 * 1000;
-const MUSIC_XFADE_MS  = (typeof window !== "undefined" && window.__hefMusicXfadeMs)  || 6000;
+const MUSIC_XFADE_MS = (typeof window !== "undefined" && window.__hefMusicXfadeMs) || 6000;
+const MUSIC_XFADE_S = MUSIC_XFADE_MS / 1000;
 function musicTrackUrl(i) {
   return mediaBase() + "audio/" + MUSIC_PLAYLIST[HEFScrub.wrapIndex(i, MUSIC_PLAYLIST.length)];
 }
-let musicIdx = -1;     // index of the track on the active music element (-1 = not started)
-let musicEl = null;    // the element currently carrying the active music track
-let musicTimer = null; // rotation timer
+let musicIdx = -1;         // index of the track on the active music element (-1 = not started)
+let musicEl = null;        // the element currently carrying the active music track
+let musicXfading = false;  // true during a track→track crossfade (guards re-entry)
 
 // The url the active source would play right now (for the diagnostic readout).
 function currentAudioUrl() {
@@ -1582,40 +1584,62 @@ function silenceAll() {
   fadeVolume(audB, 0, FADE_MS, () => audB.pause());
 }
 
-function scheduleMusicRotate() {
-  clearTimeout(musicTimer);
-  musicTimer = setTimeout(rotateMusic, MUSIC_ROTATE_MS);
-}
-// Crossfade the active music element out and a random OTHER track in on the other element.
-function rotateMusic() {
-  if (audioSource() !== "music" || audioVol() === 0 || musicIdx < 0) { scheduleMusicRotate(); return; }
+// Crossfade the finishing track out and a random OTHER track in on the other element.
+function advanceMusic() {
+  if (audioSource() !== "music" || audioVol() === 0 || musicIdx < 0) return;
+  musicXfading = true;
   const next = HEFScrub.pickNextIndex(musicIdx, MUSIC_PLAYLIST.length, Math.random());
   const nextEl = musicEl === aud ? audB : aud;
-  ensurePlaying(nextEl, musicTrackUrl(next), 0);                  // incoming track, silent...
-  fadeVolume(nextEl, audioVol(), MUSIC_XFADE_MS);                 // ...fade it in,
-  fadeVolume(musicEl, 0, MUSIC_XFADE_MS, () => musicEl.pause());  // ...fade the old out.
+  const prevEl = musicEl;
+  ensurePlaying(nextEl, musicTrackUrl(next), 0);                             // incoming track, silent...
+  fadeVolume(nextEl, audioVol(), MUSIC_XFADE_MS, () => { musicXfading = false; });  // ...fade it in,
+  fadeVolume(prevEl, 0, MUSIC_XFADE_MS, () => prevEl.pause());               // ...fade the finishing one out.
   musicEl = nextEl; musicIdx = next;
-  scheduleMusicRotate();
   updateAudioStatus();
 }
-// Start the rotation (first call) or just re-apply the master volume to the active track.
-// The FIRST call runs inside the audio gesture, so we prime BOTH elements here to unlock
-// them on Safari (the timer-driven crossfade later plays the 2nd element outside a gesture).
+// timeupdate: a few seconds before the active track ends, crossfade to a random next
+// (gapless). Only the active element, in Music mode, once per track.
+function onMusicProgress(e) {
+  if (musicXfading || audioSource() !== "music" || musicIdx < 0 || e.target !== musicEl) return;
+  const d = musicEl.duration;
+  if (d && isFinite(d) && d > MUSIC_XFADE_S * 2 && musicEl.currentTime >= d - MUSIC_XFADE_S) advanceMusic();
+}
+// ended: safety net — a track that finishes without a crossfade (short track / missed
+// timeupdate) immediately rolls a new random one, so Music never stops while selected.
+function onMusicEnded(e) {
+  if (audioSource() !== "music" || musicIdx < 0 || e.target !== musicEl) return;
+  musicXfading = false;
+  advanceMusic();
+}
+// Start playback (first call) or just re-apply the master volume to the active track. The
+// FIRST call runs inside the audio gesture, so we prime BOTH elements here to unlock them
+// on Safari (later crossfades play the 2nd element outside a gesture).
 function startMusic(vol) {
   if (musicIdx < 0) {
+    musicXfading = false;
     musicIdx = Math.floor(Math.random() * MUSIC_PLAYLIST.length);
     musicEl = aud;
     ensurePlaying(aud, musicTrackUrl(musicIdx), vol);
     ensurePlaying(audB, musicTrackUrl(musicIdx), 0);   // prime + unlock the 2nd element (silent)
-    scheduleMusicRotate();
   } else {
     cancelFade(musicEl);
     musicEl.volume = HEFScrub.clamp01(vol);
   }
   updateAudioStatus();
 }
-// Stop the rotation and reset (on leaving Music, or going silent).
-function stopMusic() { clearTimeout(musicTimer); musicTimer = null; musicIdx = -1; musicEl = null; }
+// Reset (on leaving Music, or going silent).
+function stopMusic() { musicXfading = false; musicIdx = -1; musicEl = null; }
+
+// Keep Music playing while selected: resume the active track if it stalls/pauses unexpectedly.
+function musicWatchdog() {
+  if (audioSource() !== "music" || audioVol() === 0 || musicIdx < 0 || !musicEl) return;
+  if (musicEl.paused && !musicXfading) { const pr = musicEl.play(); if (pr) pr.catch(() => {}); }
+}
+
+for (const el of [aud, audB]) {
+  el.addEventListener("timeupdate", onMusicProgress);
+  el.addEventListener("ended", onMusicEnded);
+}
 
 // Mid-segment scrub. Soundtrack: crossfade scale `loIndex` (gain 1-frac) against
 // loIndex+1 (gain frac), scaled by the master volume. Music: hold the single loop.