feedback7 R22-HUD: a skill cue that reaches the client before its unit is held and sounds once when the unit is tracked — the first cast of a deploy-time skill was silent (PR #292 by @LimitlessHPPK, without handing the whole early buffer to the sound); golden: unchanged

Seen (Grok's review, reproduced here with the real sim): the sim's deploy emits a deployment-activated skill's
['skill', id, 1] before the unit's ['spawn', unitInfo] (宴: three events earlier) and audio.js dropped a skill event of an
unknown unit, so that one cast made no sound while every later one did.

- audio.js: pendingSkill — a 'skill' ON for an unknown unit is held (one per unit, 64 at most, the oldest go first);
  _track plays it once when the unit's spawn arrives; a skill OFF is no cast and is not held; setFieldUnits drops the holds.
  Changed from the PR: setFieldUnits clears the holds BEFORE it tracks the new field's units (the PR cleared after, so a hold
  left over from the previous field would have sounded for a unit of the new field that shares its id — ids are per battle).
- screens/game.js: NOT the PR's change. The pre-entry buffer (keepEarly: every spawn, die, deploy, status and skill since the
  field's m.field, up to 1500 of them) is handed to the sound as its 'spawn' tuples only (new early.js audioEarly): the whole
  list would play every old death, deploy line and cast at once on entering. The live path (onEv) already forwards the full
  list, so the hold alone fixes the live silent first cast; a deploy-tick cast that falls into the short pre-entry gap
  stays unheard (a deliberate gap — replaying "only the casts before their spawn" would still sound a minute-old cast when a
  field was buffered while another one was on screen).
- Tests: test/ui/audio.test.js (3: the held cast in one batch and across batches, once, no hold for a skill OFF; a hold does
  not outlive its field and is bounded; 宴's real deploy: the sim's cast comes before the spawn and sounds exactly once — all
  fail on the parent) and test/match/feedback1-runner-forms.test.js (the audio gets the spawn tuples only: silent replay that
  still teaches the units, the next live cast sounds; the whole list would have sounded old cues). Docs: design/client.md.
- Golden: unchanged (client audio only).

test/ui/audio.test.js

@@ -577,6 +577,89 @@ describe('AudioManager', () => {
       } finally { globalThis.fetch = origFetch; }
     }
   });
+
+  // 「技能音效有时候不触发」 (PR #292 by @LimitlessHPPK): the sim emits the cast of a deployment that fires inside its own first
+  // tick (`initSp` already at `spCost`, 宴's deploy-timed skill, 银灰 S3 真银斩 …) before the unit's `['spawn', unitInfo]` — the
+  // same batch, or the next — so `handleBattleEvents` used to skip the cue for good: that first cast was silent and every
+  // later one played. The cue is held and answered once, when the unit is tracked (`_track`); it never outlives its field.
+  test('a cast that arrives before its unit is known is held and plays once when the unit is tracked', () => {
+    const vm = { audio: { sfx: { ui: {}, battle: {}, units: { char_a: { skill: '/s/a_skill.mp3' } } },
+      voice: { char_a: { skill3: '/v/a_s3.mp3' } } } };
+    const a = new AudioManager({ win: null, getManifest: () => vm });
+    a.ctx = {};                                   // unlocked: every path below is the real one
+    const played = [], voiced = [];
+    a._play = (url) => { played.push(url); };     // the cue itself, and the 作战中 line that goes with it
+    a.voice = (charId, slot, o) => { voiced.push([charId, slot, o.unitKey]); return true; };
+    /** UnitInfo of the operator `char_a` (spine = the sfx.units key; skillIndex picks its 作战中N slot). */
+    const info = (id, skillIndex) => ({ id, side: 'ally', spine: 'char_a', kind: 'op', skillIndex });
+
+    // (1) the sim's order inside one batch: the cast, then the unit's spawn — the cast waits, then sounds once
+    a.handleBattleEvents([['skill', 8, 1]]);
+    assert.deepEqual(played, [], 'nothing to play yet: the unit is unknown');
+    a.handleBattleEvents([['spawn', info(8, 2)]]);
+    assert.deepEqual(played, ['/s/a_skill.mp3'], 'the held cast plays as soon as the unit is tracked');
+    assert.deepEqual(voiced, [['char_a', 'skill3', 8]], 'with the 作战中N line its skillIndex picks');
+    a.handleBattleEvents([['skill', 7, 1], ['atk', 7, 8, 'none'], ['spawn', info(7, 0)]]);
+    assert.equal(played.length, 2, 'the same batch: the cast waits for the spawn of its own batch');
+    assert.deepEqual(voiced.at(-1), ['char_a', 'skill1', 7]);
+    // (2) once: a unit that is told about again (a repeated spawn) never replays it; a later cast plays directly
+    a.handleBattleEvents([['spawn', info(8, 2)], ['spawn', info(7, 0)]]);
+    assert.equal(played.length, 2, 'no second cue for the held cast');
+    a.handleBattleEvents([['skill', 8, 1]]);
+    assert.equal(played.length, 3, 'a later cast of a known unit plays through');
+    assert.deepEqual(voiced.at(-1), ['char_a', 'skill3', 8], 'and sounds the same as the replayed one');
+    // (3) skill off (`['skill', id, 0]`) is no cast: nothing is held for it
+    a.handleBattleEvents([['skill', 9, 0]]);
+    a.handleBattleEvents([['spawn', info(9, 0)]]);
+    assert.equal(played.length, 3, 'the off event holds nothing');
+    assert.equal(a.pendingSkill.size, 0);
+  });
+
+  test('a held cast does not outlive its field: a unit of the next field that shares its id does not sound it', () => {
+    const vm = { audio: { sfx: { ui: {}, battle: {}, units: { char_a: { skill: '/s/a_skill.mp3' } } }, voice: {} } };
+    const a = new AudioManager({ win: null, getManifest: () => vm });
+    a.ctx = {};
+    const played = [];
+    a._play = (url) => { played.push(url); };
+    a.voice = () => true;
+    const info = (id) => ({ id, side: 'ally', spine: 'char_a', kind: 'op' });
+    a.handleBattleEvents([['skill', 9, 1]]);          // a cast whose unit never appeared on this field
+    assert.equal(a.pendingSkill.size, 1);
+    a.setFieldUnits([info(9)]);                       // another battle: unit ids are per battle, 9 is a different unit
+    assert.equal(a.pendingSkill.size, 0, 'the field change drops the hold');
+    a.handleBattleEvents([['spawn', info(9)]]);
+    assert.deepEqual(played, [], 'the old field\'s cast never sounds in the new one');
+    // the hold is bounded: casts of units that never appear cannot pile up
+    for (let id = 100; id < 400; id++) a.handleBattleEvents([['skill', id, 1]]);
+    assert.ok(a.pendingSkill.size <= 64, `${a.pendingSkill.size} holds`);
+    assert.ok(a.pendingSkill.has(399) && !a.pendingSkill.has(100), 'the oldest holds go first');
+  });
+
+  test('a real battle: the deploy-tick cast of a deployment-activated skill is heard, once', () => {
+    // The reported shape in 0.2.0's own sim: 宴's kit activates its skill on deployment (activateOnDeploy, PR #109), and
+    // `sim/battle/deploy.js` runs `skill.reset()` (→ `activate` → `['skill', id, 1]`) BEFORE it emits
+    // `['spawn', unitInfo]` — three events earlier in 宴's case (a status and an fx come between). Fed to the audio as
+    // the socket delivers it, that cast used to be dropped for good.
+    const chessId = 'chess_char_1_18_a';   // 宴 (char_337_utage): a deploy-timed skill with a skill sound
+    const h = makeBattle({ seed: 7, autoFinish: false, timeLimit: 5, units: [{ chessId, row: 9, col: 5 }] });
+    h.step(3);
+    const ev = h.events;
+    const iCast = ev.findIndex((e) => e[0] === 'skill' && e[2]);
+    const iSpawn = ev.findIndex((e) => e[0] === 'spawn');
+    assert.ok(iCast >= 0 && iSpawn > iCast, `the sim emits the deploy-tick cast before the unit info (${iCast} < ${iSpawn})`);
+    // the cast's sound, resolved as `unit()` does (the equipped skill's own ON_SKILL_START file, else its `skill`)
+    const info = ev[iSpawn][1];
+    const rec = manifest.audio.sfx.units[info.spine];
+    const url = (Number.isInteger(info.skillIndex) && rec?.skills ? rec.skills[info.skillIndex] : null) ?? rec?.skill;
+    assert.ok(typeof url === 'string', `前提：${info.spine} 有技能音效`);
+    const played = [];
+    const a = new AudioManager({ win: null, getManifest: () => manifest });
+    a.ctx = {};
+    a._play = (u) => { played.push(u); };
+    a.voice = () => true;
+    a.handleBattleEvents(ev);
+    assert.equal(played.filter((u) => u === url).length, 1, 'the cast of the deployment is heard, exactly once');
+  });
 });
 
 // user playtest #4 item 6: 纯烬艾雅法拉's skill sound rang outside her skill — her manifest `hit` is her S3 impact