test(audio): [PKG-AUDIO-02] cover released behavior and real media

.gitattributes

@@ -3,4 +3,5 @@
 test/browser/media/hls/*.m3u8 text eol=lf
 test/browser/fixtures/hls-grouped.m3u8 text eol=lf
 test/browser/media/hls/*.mpegts binary
+test/browser/media/*.m4a binary
 refactor/baselines/core-vendor/*.txt text eol=lf

package.json

@@ -50,7 +50,7 @@
     "ci:build": "yarn build:types && yarn build all && yarn build:i18n && yarn build:ts && yarn build:docs && yarn test:imports",
     "test:imports": "node --test test/esm.test.js test/i18n.test.js test/ssr.test.js",
     "typecheck": "node scripts/typecheck.mjs",
-    "test:unit": "node --test test/playback.test.js test/dash-control.test.js test/hls-control.test.js test/public-behavior.test.js test/helpers.test.js test/chapter.test.js test/utils.test.js test/resource-scope.test.js test/instance-lifecycle.test.js test/options.test.js test/media-hosts.test.js test/plugins.test.js test/source.test.js test/playback-properties.test.js test/media-events.test.js test/template-resources.test.js test/core-vendor.test.js test/component-resources.test.js test/setting-model.test.js test/setting-layout.test.js test/setting-resources.test.js test/subtitle.test.js test/display-native.test.js test/display-video-fullscreen.test.js test/display-pip.test.js test/display-mini.test.js test/display-sizing.test.js test/display-orientation.test.js test/hotkey.test.js test/listener-registry.test.js test/global-events.test.js test/pointer-events.test.js test/gesture.test.js test/event-scheduling.test.js test/notice.test.js test/fast-forward.test.js test/auto-playback.test.js test/builtin-layers.test.js test/prompt-components.test.js test/screenshot.test.js test/thumbnails.test.js test/progress.test.js test/environment.test.js test/storage.test.js test/facade-properties.test.js test/dom-boundaries.test.js test/initialization.test.js test/entry.test.js test/accessibility-button.test.js test/accessibility-focus.test.js test/accessibility-slider.test.js",
+    "test:unit": "node --test test/playback.test.js test/dash-control.test.js test/hls-control.test.js test/audio-track.test.js test/public-behavior.test.js test/helpers.test.js test/chapter.test.js test/utils.test.js test/resource-scope.test.js test/instance-lifecycle.test.js test/options.test.js test/media-hosts.test.js test/plugins.test.js test/source.test.js test/playback-properties.test.js test/media-events.test.js test/template-resources.test.js test/core-vendor.test.js test/component-resources.test.js test/setting-model.test.js test/setting-layout.test.js test/setting-resources.test.js test/subtitle.test.js test/display-native.test.js test/display-video-fullscreen.test.js test/display-pip.test.js test/display-mini.test.js test/display-sizing.test.js test/display-orientation.test.js test/hotkey.test.js test/listener-registry.test.js test/global-events.test.js test/pointer-events.test.js test/gesture.test.js test/event-scheduling.test.js test/notice.test.js test/fast-forward.test.js test/auto-playback.test.js test/builtin-layers.test.js test/prompt-components.test.js test/screenshot.test.js test/thumbnails.test.js test/progress.test.js test/environment.test.js test/storage.test.js test/facade-properties.test.js test/dom-boundaries.test.js test/initialization.test.js test/entry.test.js test/accessibility-button.test.js test/accessibility-focus.test.js test/accessibility-slider.test.js",
     "test:coverage": "node --test test/coverage.test.js && node scripts/coverage.mjs",
     "test": "yarn test:node && yarn test:baseline",
     "test:browser": "playwright test",

refactor/audio-validation.md

@@ -0,0 +1,61 @@
+# Audio Track 行为与媒体测试
+
+PKG-AUDIO-02；公开来源见 [1.1.0 契约](baselines/audio-track-contract.md)，
+固定执行结果及失败保留见 [验证记录](baselines/audio-validation.json)。
+
+## 已实现命令
+
+```sh
+node --test test/audio-track.test.js
+yarn ci:check
+yarn test:browser test/browser/audio-track.spec.js --trace on
+```
+
+Node 专项 38 项：源码和真实发布 main/legacy/module，初始化/延迟安装、暴露 audio、
+严格阈值、正负偏移、seek/播放前同步、playing 条件、waiting/pause、音量/静音/倍率、
+同/空/新 URL、三处 play 拒绝、销毁和多实例隔离。Audio 是记录调用的受控对象，不模拟解码。
+工厂输入跨 realm 检查使用冻结归档，源码使用既有 JS/TS loader，可随迁移继续回归。
+
+真实浏览器最终 36 项通过，无重试、跳过：每引擎 8 项新旧核心/插件播放及失败恢复，
+1 项原生 WAV 诊断、1 项旧插件空 src 销毁问题、2 项不同核心的原生暂停/结束缺陷观察。
+因此 36 通过不代表 36 项无缺陷的候选功能验收：9 项复现历史问题，3 项是原生能力诊断。
+旧核心固定 5.4.0、旧插件固定 1.1.0；候选来自源码构建，非隔离安装包。
+
+播放证据包括主视频实际解码颜色、媒体时钟、AAC 音频加载/时钟、偏移 seek、倍率/音量、
+音频切源后的同一元素及同步、503 加载失败后换源恢复。公开 audio 的事件、状态、
+原始 warning、代码/媒体/核心产物指纹随测试附件保存。不声称已经测得扬声器输出或音画主观同步。
+Node 控制 waiting/playing 与 play 拒绝；实际浏览器网络缓冲/自动播放策略和移动环境由 05 补充。
+
+## 样本与失败归因
+
+test/browser/media/audio-tone.m4a 是本地生成的 16 秒 440 Hz 单声道 AAC。
+生成命令、FFmpeg 版本、ffprobe 及哈希见旁边 audio-tone.json，测试重验哈希。
+服务器沿用已有 GET/HEAD/Range，增加 audio/mp4 MIME；无外网音频依赖。
+WAV 诊断使用整数方波，完整参数/哈希冻结。直接原生 Audio（未创建 ArtPlayer）在
+Windows WebKit 也给出错误 4；AAC 矩阵通过不能覆盖该 WAV 或真实 Safari 的能力。
+
+初轮 24 失败及后续诊断均保存，没有覆盖成绿灯：
+
+1. 测试先用了 currentTime setter；它不发 seek 事件。修正为已有公开 art.seek，未修改核心。
+2. 旧插件 src='' 后 readyState=0、paused=true，但 currentSrc 可能保留且 error=4。
+   正常基线清理检查属性/暂停/就绪状态，另立发布版缺陷断言，不把旧错误当作已修复。
+3. WAV 在 Windows WebKit 失败；用无播放器原生 Audio 对照隔离，并增加独立 AAC 测试输入。
+4. 最初 AAC route 固定返回 200 全文件，seek 返回 0；改用现有 Range 服务器，验证 seekable
+   覆盖目标再 seek。没有增加超时或移除实际 seek 断言。
+5. Windows WebKit 视频尺寸可能反映布局，既有 browser/README.md 已说明；播放证据改为
+   固定样本的真实解码像素，保留已知尺寸限制，未改媒体实现。
+
+最终源码/夹具都无生产行为变动。一次完整 CI 577 项（534+11+32）、254 个生产 TS 通过，
+最终新增的浏览器观察经定向 lint 和三引擎验证。所有失败报告/trace 均复制到独立 cache 目录，
+冻结 JSON 保存摘要、输入和关键状态；cache 丢失时应重跑，不能称旧 trace 仍存在。
+
+## 后续修复与交接
+
+- AUDIO-LIFE-01 已由旧版受控/实际媒体复现：保留的 update 可复活 src；src='' 触发新媒体错误。
+  03 应使用关闭守卫、插件自身订阅清理和无错误的媒体释放；保留同一公开 audio 及同步 update。
+- AUDIO-SYNC-01 部分已复现：主视频直接 pause 或播放结束，外部音频仍播放；03 修复原生事件同步。
+  负偏移起点/时长边界、真实缓冲和快速切源仍须在 03/05 接续，不能以本次通过关闭全部条目。
+- AUDIO-TYPE-01/DEMO-01 继续由 04/06 处理。归档分发、Monaco/8082 与设备验收尚未完成。
+
+浏览器测试均共用端口 8084 和输出目录；不要同时执行多个 suite。开始下一次前复制报告
+和结果目录（包含 trace），并记录对应测试输入。Node CI 可独立并行执行。

refactor/changes/2026-09-12-PKG-AUDIO-02-tests.md

@@ -0,0 +1,43 @@
+# PKG-AUDIO-02：外部音频行为基线
+
+状态：本步测试基线验收完成；起点 8c0a2fee。遵循已冻结的 Audio Track 1.1.0 契约。
+范围是源码及真实发布三格式的可控行为、错误与生命周期测试，以及真实浏览器的
+外部音频/主视频播放、seek、切源和清理。受控 Audio 不被描述为真实解码证据。
+公开行为不在本步修改；复现的历史问题交由 03 修复、04 类型迁移。
+
+## 交付与验证
+
+新增 test/audio-track.test.js 和窄范围受控 Audio helper，源码及发布三格式共 38 项通过。
+公开 audio、工厂延迟安装、默认阈值、偏移正负、配置更新、事件、Promise 拒绝及清理均覆盖。
+Node 测试加入现有 test:unit 脚本，不新增依赖或 lock 改动。
+
+新增 audio-track.spec.js 和自行生成的 AAC 媒体/来源 manifest，服务器复用 Range 处理。
+三引擎最终 36 项通过（其中 9 项历史缺陷复现、3 项原生能力诊断），没有重试/跳过。
+音频与视频时钟、真实解码像素、偏移 seek、音量倍率、换音源/错误恢复、清理状态均验证。
+577 项完整 CI、254 生产 TS 通过。最终浏览器补充又通过定向 lint 与三引擎执行。
+计划/风险生成校验和 Git diff 检查通过：216 项任务、126 项风险，未豁免未解决项。
+
+原始失败及下一步见 [测试说明](../audio-validation.md)，所有输入/关键状态/报告哈希冻结在
+[执行证据](../baselines/audio-validation.json)。首轮 fixture 调用错误、Range 不完整、
+WebKit 尺寸假设分别修正，没有增加超时或删掉真实播放/seek 断言。
+最初定向 lint 有换行/多语句格式错误，按现有规范修正；受控测试多宿主改为单次全局 Audio
+安装，避免多组恢复钩子的顺序污染，最终 CI 通过。
+
+## 兼容、缺陷与范围
+
+生产源码/声明/构建产物没有变更，没有新增 API、DOM/CSS 或消费者依赖。
+AUDIO-LIFE-01：发布版保留 update 可在 destroy 后写 src，且空 src 清理导致浏览器 error=4。
+AUDIO-SYNC-01：真实旧核心及候选核心中，原生暂停/自然结束后外部音频仍继续播放。
+两项保持 open，由 03 修复；本步仅把证据等级更新为已复现。
+
+负偏移起点、超时长、真实缓冲、快速切源、设备策略仍需 03/05 接续。
+WAV 在 Windows WebKit 的原生 Audio 也失败，AAC 通过不替代 WAV 或真实 Safari 认证。
+未测扬声器声音、物理设备和隔离安装包；不以本次基线关闭包发布门槛。
+实际生产模块地图随 03 源码变化交付，本步提供可重跑维护入口。
+
+## 提交与回退
+
+独立完成提交主题：`test(audio): [PKG-AUDIO-02] cover released behavior and real media`。
+回退本提交可移除新增测试/fixture/脚本接入和文档，生产播放器不受影响。
+下一步 03 开始同步与生命周期源码拆分/修复，04 接续严格 TS/公开类型。
+未 push/tag/publish/merge，全项目目标保持。

refactor/plan.md

@@ -4,7 +4,7 @@
 
 基线：`40fcda6a37d0049d42e49c1e64e70d4fd9ba5f7f`。总任务 216 项，范围 22 个包及工作区/示例。
 
-状态：todo 149 / doing 1 / blocked 0 / done 66 / deferred 0。风险 L/M/H 表示兼容风险，不表示工期。
+状态：todo 148 / doing 1 / blocked 0 / done 67 / deferred 0。风险 L/M/H 表示兼容风险，不表示工期。
 
 前置依赖是启动条件；验收是完成条件。任务可以继续拆分，但不能复用或悄悄删除旧 ID。
 
@@ -156,7 +156,7 @@
 | ID | 范围 / 步骤 | 前置依赖 | 交付物 | 验收条件 | 风险 | 状态 |
 | --- | --- | --- | --- | --- | --- | --- |
 | PKG-AUDIO-01 | artplayer-plugin-audio-track<br>核对包契约与历史用法 | BASE-05 | url/offset/sync、audio 实例暴露、update 与音量语义 | 源码/声明/README/demo/发布包差异已登记；公开形状和版本范围冻结 | H | done |
-| PKG-AUDIO-02 | artplayer-plugin-audio-track<br>建立特有行为与错误测试 | PKG-AUDIO-01, ENG-03, ENG-05 | 偏移、倍率、seek、waiting/playing、加载错误和 autoplay 拒绝 | 旧版本行为可重跑，成功/失败/切源/销毁有必要断言 | H | todo |
+| PKG-AUDIO-02 | artplayer-plugin-audio-track<br>建立特有行为与错误测试 | PKG-AUDIO-01, ENG-03, ENG-05 | 偏移、倍率、seek、waiting/playing、加载错误和 autoplay 拒绝 | 旧版本行为可重跑，成功/失败/切源/销毁有必要断言 | H | done |
 | PKG-AUDIO-03 | artplayer-plugin-audio-track<br>整理内部职责与资源 | PKG-AUDIO-02, CORE-10 | 外部 audio 的同步策略、监听与源更新生命周期 | 结构变化和缺陷修复分开记录；原 API/事件/资源生命周期通过 | H | todo |
 | PKG-AUDIO-04 | artplayer-plugin-audio-track<br>迁移自有源码和公开类型 | PKG-AUDIO-03, ENG-04, ENG-06, CORE-07 | Option/Result/audio、update 输入和事件类型 | 严格类型检查、旧消费样例通过；声明路径/导出和同步异步兼容 | H | todo |
 | PKG-AUDIO-05 | artplayer-plugin-audio-track<br>验证新旧核心和组合 | PKG-AUDIO-04, CORE-22 | 主视频切源和缓冲恢复，多实例独立音频、旧核心 | 最终核心与原支持范围核心分别通过；设备/SDK 缺证据不能标完成 | H | todo |
@@ -467,6 +467,7 @@
 - PKG-CHAPTER-03: [记录](changes/2026-09-10-PKG-CHAPTER-03-typescript-modules.md) [记录](baselines/chapter-migration-validation.json)
 - PKG-CHAPTER-04: [记录](changes/2026-09-10-PKG-CHAPTER-04-public-types.md) [记录](baselines/chapter-types-validation.json)
 - PKG-AUDIO-01: [记录](changes/2026-09-12-PKG-AUDIO-01-contract.md) [记录](baselines/audio-track-contract.md) [记录](baselines/audio-track-release.json)
+- PKG-AUDIO-02: [记录](changes/2026-09-12-PKG-AUDIO-02-tests.md) [记录](audio-validation.md) [记录](baselines/audio-validation.json)
 - PKG-HLS-01: [记录](baselines/hls-control-contract.md) [记录](baselines/hls-control-release.json) [记录](changes/2026-09-11-PKG-HLS-01-contract.md)
 - PKG-HLS-02: [记录](hls-validation.md) [记录](baselines/hls-sdk.json) [记录](baselines/hls-validation.json) [记录](changes/2026-09-11-PKG-HLS-02-tests.md)
 - PKG-HLS-03: [记录](changes/2026-09-12-PKG-HLS-03-modules.md) [记录](baselines/hls-modules-validation.json) [记录](hls-validation.md)

refactor/progress.md

@@ -1,5 +1,18 @@
 # 进度与证据
 
+## 最新完成：PKG-AUDIO-02 行为与真实媒体基线
+
+38 项 Node 契约覆盖源码和发布三格式，完整 CI 577 项、254 个生产 TS 通过。
+三引擎最终 36 项通过、零失败/重试/跳过；其中 9 项为旧版缺陷复现、3 项为原生 WAV
+能力诊断，不能把这些数量全部作为无缺陷候选验收。真实 AAC/视频播放、偏移 seek、
+音量倍率、音频切源/503 恢复已验证。原始夹具失败与归因/trace 均保留。
+
+旧插件销毁后 update 可复活、src='' 新生媒体错误、原生视频暂停/结束未停外部音频
+已有证据；AUDIO-LIFE-01/SYNC-01 仍 open，03 接续源码拆分修复。
+当前 216 项、67 done、1 doing、148 todo；HLS 仍保持原发布门槛。
+Audio-01 已提交 8c0a2fee，Audio-02 独立本地提交后核实，再进入 03。
+详见 [测试说明](audio-validation.md) 和 [记录](changes/2026-09-12-PKG-AUDIO-02-tests.md)。
+
 ## 最新完成：PKG-AUDIO-01 外部音轨发布契约
 
 冻结 npm audio-track 1.1.0 六文件及完整性，manifest/README/声明和起点一致，

refactor/risk-table.md

@@ -126,7 +126,7 @@
 | HLS-ENV-01 | open / 已复现 | Windows WebKit 缺失 MSE，HLS 播放矩阵尚缺 Safari 证据 | PKG-HLS-05, REL-09, REVIEW-02 |
 | HLS-CRASH-01 | open / 已复现 | Firefox Hls 1.5.17 worker 销毁可在原生 video 与候选核心复现崩溃 | PKG-HLS-SDK-01, PKG-HLS-05, REVIEW-02 |
 | HLS-PLAYBACK-01 | open / 已复现 | Firefox 旧核心与 Hls 1.7.2 切组后视频档位未完成切换 | PKG-HLS-SDK-01, PKG-HLS-05, REVIEW-02 |
-| AUDIO-LIFE-01 | open / 源码/产物事实 | Audio Track 销毁后 update 与媒体/订阅缺少终止守卫 | PKG-AUDIO-02, PKG-AUDIO-03, PKG-AUDIO-05 |
-| AUDIO-SYNC-01 | open / 待取证 | Audio Track 偏移边界和切源/缓冲恢复尚缺真实时序证据 | PKG-AUDIO-02, PKG-AUDIO-03, PKG-AUDIO-05 |
+| AUDIO-LIFE-01 | open / 已复现 | Audio Track 销毁后 update 与媒体/订阅缺少终止守卫 | PKG-AUDIO-02, PKG-AUDIO-03, PKG-AUDIO-05 |
+| AUDIO-SYNC-01 | open / 已复现 | Audio Track 未同步原生暂停/结束，偏移边界与切源/缓冲仍待完整验证 | PKG-AUDIO-02, PKG-AUDIO-03, PKG-AUDIO-05 |
 | AUDIO-TYPE-01 | open / 源码/产物事实 | Audio Track update 部分配置与公开/编辑器声明不一致 | PKG-AUDIO-04 |
 | AUDIO-DEMO-01 | open / 源码/产物事实 | Audio Track README 示例链接名称不匹配且缺维护说明 | PKG-AUDIO-06 |

refactor/risks.json

@@ -2647,7 +2647,7 @@
     {
       "id": "AUDIO-LIFE-01",
       "title": "Audio Track 销毁后 update 与媒体/订阅缺少终止守卫",
-      "confirmation": "source-observed",
+      "confirmation": "reproduced",
       "status": "open",
       "owners": [
         "PKG-AUDIO-02",
@@ -2656,15 +2656,18 @@
       ],
       "evidence": [
         "refactor/baselines/audio-track-contract.md",
-        "refactor/baselines/audio-track-release.json"
+        "refactor/baselines/audio-track-release.json",
+        "test/audio-track.test.js",
+        "test/browser/audio-track.spec.js",
+        "refactor/baselines/audio-validation.json"
       ],
       "compatibleResolution": "保留公开 audio 和同步 update，封闭销毁后的资源写入并管理插件订阅，验证待决播放拒绝。",
       "closureCriteria": "受控复现和新旧核心真实媒体切源/销毁验证通过，不以源码观察代替泄漏证据。"
     },
     {
       "id": "AUDIO-SYNC-01",
-      "title": "Audio Track 偏移边界和切源/缓冲恢复尚缺真实时序证据",
-      "confirmation": "unverified",
+      "title": "Audio Track 未同步原生暂停/结束，偏移边界与切源/缓冲仍待完整验证",
+      "confirmation": "reproduced",
       "status": "open",
       "owners": [
         "PKG-AUDIO-02",
@@ -2673,7 +2676,10 @@
       ],
       "evidence": [
         "refactor/baselines/audio-track-contract.md",
-        "refactor/baselines/audio-track-release.json"
+        "refactor/baselines/audio-track-release.json",
+        "test/audio-track.test.js",
+        "test/browser/audio-track.spec.js",
+        "refactor/baselines/audio-validation.json"
       ],
       "compatibleResolution": "固定严格阈值、偏移正负、倍率和音量语义；实测负目标/超时长及连续切源，按证据修复。",
       "closureCriteria": "正常/边界/失败/缓冲恢复有媒体与受控断言，实际支持环境缺口明确处理。"

refactor/tasks.json

@@ -1490,11 +1490,15 @@
         "ENG-03",
         "ENG-05"
       ],
-      "status": "todo",
+      "status": "done",
       "risk": "H",
       "deliverable": "偏移、倍率、seek、waiting/playing、加载错误和 autoplay 拒绝",
       "acceptance": "旧版本行为可重跑，成功/失败/切源/销毁有必要断言",
-      "evidence": []
+      "evidence": [
+        "changes/2026-09-12-PKG-AUDIO-02-tests.md",
+        "audio-validation.md",
+        "baselines/audio-validation.json"
+      ]
     },
     {
       "id": "PKG-AUDIO-03",

test/README.md

@@ -40,3 +40,8 @@ Blob URL contents and cleanup when a controlled click fails.
 See [browser/README.md](browser/README.md) for `yarn test:browser`, browser installation,
 published/current combinations, media fixtures, candidate mapping and failure reports.
 These tests are separate from the fast Node suite and run in the Browser playback smoke CI job.
+
+`test/audio-track.test.js` compares source and published Audio Track 1.1.0 in all three
+formats with a controlled Audio object: timing intent, offsets, source updates, rejection,
+volume/rate, independent instances and cleanup. Published-only tests retain defect evidence.
+See [audio validation](../refactor/audio-validation.md) for actual media tests and limitations.

test/audio-track.test.js

@@ -0,0 +1,167 @@
+import assert from 'node:assert/strict'
+// eslint-disable-next-line test/no-import-node-test -- Controlled media contracts use Node's runner.
+import { test } from 'node:test'
+import { audioHost, audioImplementations, createAudioArt } from './helpers/audio-track.js'
+
+const implementations = await audioImplementations()
+for (const { name, factory } of implementations) {
+  test(`${name}: synchronous lazy installation, exposed audio and initial media properties`, (t) => {
+    const { art, instances } = audioHost(t)
+    const option = { url: 'first.aac' }
+    const attach = factory(option)
+    assert.equal(instances.length, 0)
+    option.url = 'before-install.aac'
+    const plugin = attach(art)
+    assert.equal(plugin.name, 'artplayerPluginAudioTrack')
+    assert.deepEqual(Object.keys(plugin).sort(), ['audio', 'name', 'update'])
+    assert.equal(plugin.audio, instances[0])
+    assert.deepEqual(plugin.audio.calls, [['preload', 'auto'], ['src', 'before-install.aac'], ['volume', 0.6], ['muted', false], ['playbackRate', 1.25]])
+    assert.equal(plugin.update({}), undefined)
+    assert.equal(art.muted, false, 'Plugin must not mute the main video')
+  })
+
+  test(`${name}: default threshold is strict and offset applies in both directions`, (t) => {
+    const { art } = audioHost(t)
+    const { audio, update } = factory({ url: 'audio.aac' })(art)
+    audio.calls.length = 0
+    art.currentTime = 0.3
+    art.emit('seek')
+    assert.deepEqual(audio.calls, [])
+    art.currentTime = 0.31
+    art.emit('seek')
+    assert.deepEqual(audio.calls, [['currentTime', 0.31]])
+    update({ offset: 2, sync: 0 })
+    art.currentTime = 4
+    art.emit('seek')
+    assert.equal(audio.currentTime, 6)
+    update({ offset: -1 })
+    art.emit('seek')
+    assert.equal(audio.currentTime, 3)
+  })
+
+  test(`${name}: play synchronizes before playback and timeupdate only follows playing video`, (t) => {
+    const { art } = audioHost(t)
+    const { audio } = factory({ url: 'audio.aac' })(art)
+    audio.calls.length = 0
+    art.currentTime = 4
+    art.emit('video:timeupdate')
+    assert.deepEqual(audio.calls, [])
+    art.emit('play')
+    assert.deepEqual(audio.calls, [['currentTime', 4], ['play']])
+    art.playing = true
+    art.currentTime = 5
+    art.emit('video:timeupdate')
+    assert.equal(audio.currentTime, 5)
+    art.video = null
+    audio.calls.length = 0
+    art.emit('seek')
+    assert.deepEqual(audio.calls, [])
+  })
+
+  test(`${name}: waiting pauses, playing resumes conditionally, pause always stops audio`, (t) => {
+    const { art } = audioHost(t)
+    const { audio } = factory({ url: 'audio.aac' })(art)
+    audio.calls.length = 0
+    art.emit('video:waiting').emit('video:playing')
+    assert.deepEqual(audio.calls, [['pause']])
+    art.playing = true
+    art.emit('video:playing').emit('pause')
+    assert.deepEqual(audio.calls, [['pause'], ['play'], ['pause']])
+  })
+
+  test(`${name}: independent volume mute and rate changes follow the host`, (t) => {
+    const { art } = audioHost(t)
+    const { audio } = factory({ url: 'audio.aac' })(art)
+    art.volume = 0
+    art.muted = true
+    art.video.playbackRate = 2
+    art.emit('video:volumechange').emit('video:ratechange')
+    assert.equal(audio.volume, 0)
+    assert.equal(audio.muted, true)
+    assert.equal(audio.playbackRate, 2)
+    art.video = undefined
+    assert.equal(factory({ url: '' })(art).audio.playbackRate, 1)
+  })
+
+  test(`${name}: same and empty URLs do not reload; changed source preserves audio identity`, (t) => {
+    const { art, instances } = audioHost(t)
+    const plugin = factory({ url: 'audio.aac' })(art)
+    plugin.audio.calls.length = 0
+    plugin.update({ url: 'audio.aac' })
+    plugin.update({ url: '' })
+    assert.deepEqual(plugin.audio.calls, [])
+    assert.equal(plugin.update({ url: 'paused.aac' }), undefined)
+    assert.deepEqual(plugin.audio.calls, [['src', 'paused.aac']])
+    art.playing = true
+    plugin.audio.calls.length = 0
+    plugin.update({ url: 'playing.aac' })
+    assert.deepEqual(plugin.audio.calls, [['src', 'playing.aac'], ['play']])
+    assert.equal(plugin.audio, instances[0])
+    assert.equal(instances.length, 1)
+  })
+
+  test(`${name}: an empty initial URL stays inert until configured`, (t) => {
+    const { art } = audioHost(t)
+    const { audio, update } = factory({ url: '' })(art)
+    art.currentTime = 3
+    art.playing = true
+    audio.calls.length = 0
+    art.emit('play').emit('seek').emit('video:timeupdate').emit('video:playing')
+    assert.deepEqual(audio.calls, [])
+    update({ url: 'configured.aac' })
+    assert.deepEqual(audio.calls, [['src', 'configured.aac'], ['play']])
+  })
+
+  test(`${name}: rejection at all three play sites is observed as the original warning`, async (t) => {
+    const { art, setPlay, warnings } = audioHost(t)
+    const plugin = factory({ url: 'audio.aac' })(art)
+    const rejection = new Error('Controlled NotAllowedError')
+    setPlay(() => Promise.reject(rejection))
+    art.playing = true
+    art.emit('play')
+    await Promise.resolve()
+    art.emit('video:playing')
+    await Promise.resolve()
+    assert.equal(plugin.update({ url: 'next.aac' }), undefined)
+    await Promise.resolve()
+    assert.deepEqual(warnings, [rejection, rejection, rejection])
+  })
+
+  test(`${name}: destroy releases the exposed media and multiple hosts stay independent`, (t) => {
+    const first = audioHost(t)
+    const second = createAudioArt()
+    const left = factory({ url: 'left.aac' })(first.art)
+    const right = factory({ url: 'right.aac' })(second.art)
+    assert.notEqual(left.audio, right.audio)
+    left.audio.calls.length = 0
+    right.audio.calls.length = 0
+    first.art.emit('destroy')
+    assert.deepEqual(left.audio.calls, [['pause'], ['src', ''], ['load']])
+    assert.deepEqual(right.audio.calls, [])
+    second.art.currentTime = 2
+    second.art.emit('seek')
+    assert.equal(right.audio.currentTime, 2)
+  })
+}
+
+const historical = implementations.find(item => item.name === 'published-main').factory
+test('published defect AUDIO-LIFE-01: retained update reloads audio after destroy', (t) => {
+  const { art, listeners } = audioHost(t)
+  const plugin = historical({ url: 'audio.aac' })(art)
+  art.emit('destroy')
+  plugin.audio.calls.length = 0
+  plugin.update({ url: 'revived.aac' })
+  assert.deepEqual(plugin.audio.calls, [['src', 'revived.aac']])
+  assert.equal([...listeners.values()].reduce((count, set) => count + set.size, 0), 9)
+})
+
+test('published observation: offset update is deferred, negative target is written without clamping', (t) => {
+  const { art } = audioHost(t)
+  const plugin = historical({ url: 'audio.aac' })(art)
+  plugin.audio.calls.length = 0
+  plugin.update({ offset: -2 })
+  assert.deepEqual(plugin.audio.calls, [])
+  art.currentTime = 0
+  art.emit('seek')
+  assert.deepEqual(plugin.audio.calls, [['currentTime', -2]])
+})

test/browser/README.md

@@ -1,5 +1,10 @@
 # Browser regression entry
 
+Audio Track tests use the source and frozen 1.1.0 plugin on both cores. The local AAC fixture
+has a pinned hash and generation command in media/audio-tone.json and uses the existing Range
+server. The suite retains published cleanup/native-pause defects as explicit observations.
+See [audio validation](../../refactor/audio-validation.md) for passed scope and device limitations.
+
 Use the pinned Node and Yarn versions, then run:
 
 ```sh

test/browser/audio-track.spec.js

@@ -0,0 +1,206 @@
+import assert from 'node:assert/strict'
+import { Buffer } from 'node:buffer'
+import fs from 'node:fs'
+import process from 'node:process'
+import { ensureArchive, hash, readMember } from '../../refactor/scripts/releases.mjs'
+import { compilePackage } from '../helpers/load.js'
+import { expect, test } from './fixtures.js'
+
+let publishedCode
+let sourceCode
+let evidence
+const samples = 16000 * 16
+const tone = fs.readFileSync(new URL('./media/audio-tone.m4a', import.meta.url))
+const toneManifest = JSON.parse(fs.readFileSync(new URL('./media/audio-tone.json', import.meta.url)))
+const wav = Buffer.alloc(44 + samples * 2)
+wav.write('RIFF', 0)
+wav.writeUInt32LE(wav.length - 8, 4)
+wav.write('WAVEfmt ', 8)
+wav.writeUInt32LE(16, 16)
+wav.writeUInt16LE(1, 20)
+wav.writeUInt16LE(1, 22)
+wav.writeUInt32LE(16000, 24)
+wav.writeUInt32LE(32000, 28)
+wav.writeUInt16LE(2, 32)
+wav.writeUInt16LE(16, 34)
+wav.write('data', 36)
+wav.writeUInt32LE(samples * 2, 40)
+for (let index = 0; index < samples; index++)
+  wav.writeInt16LE(index % 80 < 40 ? 2000 : -2000, 44 + index * 2)
+
+test.beforeAll(async () => {
+  assert.equal(hash(tone), toneManifest.sha256)
+  assert.equal(tone.length, toneManifest.bytes)
+  assert(!process.env.ARTPLAYER_BROWSER_ARTIFACTS, 'Audio source tests cannot represent installed artifacts')
+  const { release } = JSON.parse(fs.readFileSync(new URL('../../refactor/baselines/audio-track-release.json', import.meta.url)))
+  const member = 'package/dist/artplayer-plugin-audio-track.js'
+  const bytes = readMember(await ensureArchive(release), member)
+  assert.equal(hash(bytes), release.files[member])
+  publishedCode = bytes.toString()
+  sourceCode = await compilePackage(release.name, 'umd')
+  evidence = { release, sourceSHA256: hash(sourceCode), audio: { sha256: hash(tone), bytes: tone.length, format: 'AAC mono 48000 Hz, 16 seconds, 440 Hz tone in MP4' }, wav: { sha256: hash(wav), bytes: wav.length, format: 'PCM16LE mono 16000 Hz, 16 seconds, integer square wave 200 Hz' }, scope: 'Source browser baseline; no physical device or installed package acceptance' }
+})
+
+test.afterEach(async ({ page }, testInfo) => {
+  const state = await page.evaluate(() => {
+    const audio = window.audioPlugin?.audio
+    const video = window.art?.video
+    const media = element => element && ({ src: element.currentSrc, attribute: element.getAttribute('src'), time: element.currentTime, paused: element.paused, readyState: element.readyState, networkState: element.networkState, error: element.error?.code, rate: element.playbackRate, seekable: Array.from({ length: element.seekable.length }, (_, index) => [element.seekable.start(index), element.seekable.end(index)]) })
+    return { audio: media(audio), video: media(video), events: window.audioEvents, warnings: window.audioWarnings }
+  }).catch(error => ({ error: error.message }))
+  await testInfo.attach('audio-state', { contentType: 'application/json', body: JSON.stringify(state) })
+})
+
+async function openAudio(page, core, plugin, testInfo, url = '/test/audio-tone.m4a?source=first') {
+  await testInfo.attach('audio-inputs', { contentType: 'application/json', body: JSON.stringify(evidence) })
+  await page.goto(`/test/player.html?core=${core}`)
+  await page.addScriptTag({ content: plugin === 'published' ? publishedCode : sourceCode })
+  await page.evaluate((url) => {
+    window.audioEvents = []
+    window.audioWarnings = []
+    const warn = console.warn.bind(console)
+    console.warn = (...args) => {
+      window.audioWarnings.push(args.map(String))
+      warn(...args)
+    }
+    window.art = new window.Artplayer({
+      container: '.player',
+      url: '/test/pattern.mp4',
+      muted: true,
+      plugins: [window.artplayerPluginAudioTrack({ url, sync: 0.1 })],
+    })
+    window.audioPlugin = window.art.plugins.artplayerPluginAudioTrack
+    for (const event of ['loadedmetadata', 'playing', 'pause', 'seeked', 'error', 'emptied'])
+      window.audioPlugin.audio.addEventListener(event, () => window.audioEvents.push({ event, time: window.audioPlugin.audio.currentTime, src: window.audioPlugin.audio.currentSrc }))
+    document.querySelector('#play').onclick = () => window.art.play()
+  }, url)
+  await expect.poll(() => page.evaluate(() => window.art.isReady)).toBe(true)
+  if (url)
+    await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.readyState)).toBeGreaterThanOrEqual(2)
+}
+
+test('native WAV diagnostic isolates sample decoding from ArtPlayer and plugin', async ({ page }, testInfo) => {
+  await page.route('**/native-wave.wav', route => route.fulfill({ contentType: 'audio/wav', body: wav }))
+  await page.goto('/test/player.html')
+  await page.evaluate(() => {
+    window.nativeAudio = new Audio()
+    window.nativeAudio.muted = true
+    window.nativeAudio.src = '/native-wave.wav'
+  })
+  await expect.poll(() => page.evaluate(() => window.nativeAudio.readyState >= 2 || Boolean(window.nativeAudio.error))).toBe(true)
+  const state = await page.evaluate(() => ({ canPlay: window.nativeAudio.canPlayType('audio/wav'), readyState: window.nativeAudio.readyState, error: window.nativeAudio.error?.code || null, playerCreated: Boolean(window.art) }))
+  expect(state.playerCreated).toBe(false)
+  await testInfo.attach('native-wav-capability', { contentType: 'application/json', body: JSON.stringify(state) })
+  if (!state.error) {
+    await page.evaluate(() => window.nativeAudio.play())
+    await expect.poll(() => page.evaluate(() => window.nativeAudio.currentTime)).toBeGreaterThan(0.2)
+  }
+  else {
+    expect(state.error).toBe(4)
+  }
+  await page.evaluate(() => {
+    window.nativeAudio.pause()
+    window.nativeAudio.removeAttribute('src')
+    window.nativeAudio.load()
+  })
+})
+
+test('published AUDIO-LIFE-01: empty src cleanup produces a native media error', async ({ page }, testInfo) => {
+  await openAudio(page, 'published', 'published', testInfo)
+  await page.locator('#play').click()
+  await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.currentTime)).toBeGreaterThan(0.2)
+  await page.evaluate(() => window.art.destroy())
+  await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.error?.code)).toBe(4)
+  expect(await page.evaluate(() => window.audioPlugin.audio.getAttribute('src'))).toBe('')
+  expect(await page.evaluate(() => window.audioPlugin.audio.readyState)).toBe(0)
+})
+
+for (const core of ['published', 'candidate']) {
+  test(`${core} core + published audio: native pause and end leave external audio playing`, async ({ page }, testInfo) => {
+    await openAudio(page, core, 'published', testInfo)
+    await page.locator('#play').click()
+    await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.currentTime)).toBeGreaterThan(0.2)
+    await page.evaluate(() => window.art.video.pause())
+    expect(await page.evaluate(() => window.art.video.paused)).toBe(true)
+    expect(await page.evaluate(() => window.audioPlugin.audio.paused)).toBe(false)
+    await page.evaluate(() => {
+      window.art.seek = 7.8
+      window.art.play()
+    })
+    await expect.poll(() => page.evaluate(() => window.art.video.ended)).toBe(true)
+    expect(await page.evaluate(() => window.audioPlugin.audio.paused)).toBe(false)
+    await testInfo.attach('published-native-pause-end', { contentType: 'application/json', body: JSON.stringify(await page.evaluate(() => ({ videoEnded: window.art.video.ended, videoPaused: window.art.video.paused, audioPaused: window.audioPlugin.audio.paused, audioTime: window.audioPlugin.audio.currentTime }))) })
+    await page.evaluate(() => window.art.destroy())
+  })
+
+  for (const plugin of ['published', 'source']) {
+    test(`${core} core + ${plugin} audio: decoded play, offset seek, rate, source and cleanup`, async ({ page }, testInfo) => {
+      await openAudio(page, core, plugin, testInfo)
+      await page.locator('#play').click()
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.currentTime)).toBeGreaterThan(0.3)
+      await expect.poll(() => page.evaluate(() => window.art.currentTime)).toBeGreaterThan(0.3)
+      expect(await page.evaluate(() => window.audioPlugin.audio.duration)).toBe(16)
+      // Windows WebKit may expose layout size; decoded pixels are the playback evidence.
+      const pixel = await page.evaluate(() => {
+        const canvas = document.createElement('canvas')
+        canvas.width = 80
+        canvas.height = 45
+        const context = canvas.getContext('2d')
+        context.drawImage(window.art.video, 0, 0, 80, 45)
+        return [...context.getImageData(30, 2, 1, 1).data]
+      })
+      expect(pixel[0]).toBeGreaterThan(180)
+      expect(pixel[1]).toBeGreaterThan(180)
+      expect(pixel[2]).toBeLessThan(80)
+      await testInfo.attach('decoded-frame-pixel', { contentType: 'application/json', body: JSON.stringify(pixel) })
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.seekable.length && window.audioPlugin.audio.seekable.end(0))).toBeGreaterThan(2.25)
+      await page.evaluate(() => {
+        window.art.pause()
+        window.audioPlugin.update({ offset: 0.25 })
+        window.art.seek = 2
+      })
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.paused)).toBe(true)
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.currentTime)).toBeCloseTo(2.25, 1)
+      await page.evaluate(() => {
+        window.art.playbackRate = 1.5
+        window.art.volume = 0.4
+      })
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.playbackRate)).toBe(1.5)
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.volume)).toBeCloseTo(0.4)
+      await page.locator('#play').click()
+      await page.evaluate(() => {
+        window.originalAudio = window.audioPlugin.audio
+        window.audioPlugin.update({ url: '/test/audio-tone.m4a?source=second' })
+      })
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.currentSrc)).toContain('source=second')
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.paused)).toBe(false)
+      await expect.poll(() => page.evaluate(() => Math.abs(window.audioPlugin.audio.currentTime - window.art.currentTime - 0.25))).toBeLessThan(0.5)
+      expect(await page.evaluate(() => window.originalAudio === window.audioPlugin.audio)).toBe(true)
+      await page.evaluate(() => {
+        window.art.pause()
+        window.art.destroy()
+      })
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.readyState)).toBe(0)
+      expect(await page.evaluate(() => window.audioPlugin.audio.getAttribute('src'))).toBe('')
+      expect(await page.evaluate(() => window.audioPlugin.audio.paused)).toBe(true)
+      expect(await page.locator('.art-video-player').count()).toBe(0)
+    })
+
+    test(`${core} core + ${plugin} audio: real load error can recover with a new source`, async ({ page }, testInfo) => {
+      await openAudio(page, core, plugin, testInfo, '')
+      await page.route('**/audio-fixture/broken.m4a', route => route.fulfill({ status: 503, body: 'Intentional media failure' }))
+      await page.evaluate(() => window.audioPlugin.update({ url: '/audio-fixture/broken.m4a' }))
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.error?.code)).toBe(4)
+      expect(await page.evaluate(() => window.art.video.error)).toBeNull()
+      await page.evaluate(() => window.audioPlugin.update({ url: '/test/audio-tone.m4a?source=recovered' }))
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.readyState)).toBeGreaterThanOrEqual(2)
+      await page.locator('#play').click()
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.currentTime)).toBeGreaterThan(0.3)
+      expect(await page.evaluate(() => window.audioPlugin.audio.error)).toBeNull()
+      await page.evaluate(() => window.art.destroy())
+      await expect.poll(() => page.evaluate(() => window.audioPlugin.audio.readyState)).toBe(0)
+      expect(await page.evaluate(() => window.audioPlugin.audio.paused)).toBe(true)
+      expect(await page.evaluate(() => window.audioPlugin.audio.getAttribute('src'))).toBe('')
+    })
+  }
+}

test/browser/media/audio-tone.json

@@ -0,0 +1,23 @@
+{
+  "schemaVersion": 1,
+  "file": "audio-tone.m4a",
+  "sha256": "83e6672b880b5d1c97093b1e26bdc40221c0b279615f40e99dbf9d2ade7b4d56",
+  "bytes": 132436,
+  "command": "ffmpeg -hide_banner -loglevel error -f lavfi -i sine=frequency=440:sample_rate=48000:duration=16 -ac 1 -c:a aac -b:a 64k -map_metadata -1 -movflags +faststart test/browser/media/audio-tone.m4a",
+  "ffmpeg": "ffmpeg version 2025-11-12-git-6cdd2cbe32-full_build-www.gyan.dev Copyright (c) 2000-2025 the FFmpeg developers",
+  "probe": {
+    "programs": [],
+    "stream_groups": [],
+    "streams": [
+      {
+        "codec_name": "aac",
+        "codec_type": "audio",
+        "sample_rate": "48000",
+        "channels": 1
+      }
+    ],
+    "format": {
+      "duration": "16.000000"
+    }
+  }
+}

test/browser/server.mjs

@@ -59,8 +59,9 @@ for (const extension of ['mp4', 'webm']) {
   const name = `test/browser/media/pattern.${extension}`
   add(`/test/pattern.${extension}`, fs.readFileSync(path.join(workspace, name)), { kind: 'generated-media', file: name })
 }
+add('/test/audio-tone.m4a', fs.readFileSync(path.join(workspace, 'test/browser/media/audio-tone.m4a')), { kind: 'generated-media', file: 'test/browser/media/audio-tone.m4a' })
 
-const mime = { '.html': 'text/html', '.js': 'text/javascript', '.mjs': 'text/javascript', '.json': 'application/json', '.css': 'text/css', '.mp4': 'video/mp4', '.webm': 'video/webm', '.vtt': 'text/vtt', '.svg': 'image/svg+xml', '.png': 'image/png', '.jpg': 'image/jpeg' }
+const mime = { '.html': 'text/html', '.js': 'text/javascript', '.mjs': 'text/javascript', '.json': 'application/json', '.css': 'text/css', '.mp4': 'video/mp4', '.m4a': 'audio/mp4', '.webm': 'video/webm', '.vtt': 'text/vtt', '.svg': 'image/svg+xml', '.png': 'image/png', '.jpg': 'image/jpeg' }
 add('/test/declaration-cues.vtt', fs.readFileSync(path.join(workspace, 'test/browser/media/declaration-cues.vtt')), { kind: 'test-subtitles', file: 'test/browser/media/declaration-cues.vtt' })
 add('/test/thumbnail-grid.svg', fs.readFileSync(path.join(workspace, 'test/browser/media/thumbnail-grid.svg')), { kind: 'test-thumbnail-grid', file: 'test/browser/media/thumbnail-grid.svg' })
 add('/test/legacy-safe-area.js', fs.readFileSync(path.join(workspace, 'test/helpers/legacy-safe-area.js')), { kind: 'frozen-own-source', file: 'test/helpers/legacy-safe-area.js', commit: 'ccf77c4e' })

test/helpers/audio-track.js

@@ -0,0 +1,99 @@
+import assert from 'node:assert/strict'
+import { Buffer } from 'node:buffer'
+import fs from 'node:fs'
+import vm from 'node:vm'
+import { ensureArchive, hash, readMember } from '../../refactor/scripts/releases.mjs'
+import { loadPackage } from './load.js'
+
+export async function audioImplementations() {
+  const { release } = JSON.parse(fs.readFileSync(new URL('../../refactor/baselines/audio-track-release.json', import.meta.url)))
+  const archive = await ensureArchive(release)
+  const implementations = [{ name: 'source', factory: (await loadPackage(release.name)).default }]
+  for (const format of ['main', 'legacy', 'module']) {
+    const member = `package/${release.manifest[format].replace(/^\.\//, '')}`
+    const bytes = readMember(archive, member)
+    assert.equal(hash(bytes), release.files[member])
+    let factory
+    if (format === 'module') {
+      factory = (await import(`data:text/javascript;base64,${Buffer.from(bytes).toString('base64')}`)).default
+    }
+    else {
+      const context = {
+        module: { exports: {} },
+        Audio: function Audio() {
+          return new globalThis.Audio()
+        },
+        console,
+      }
+      context.exports = context.module.exports
+      vm.runInNewContext(bytes.toString(), context, { timeout: 5000 })
+      factory = context.module.exports
+    }
+    implementations.push({ name: `published-${format}`, factory })
+  }
+  return implementations
+}
+
+// Records plugin intent only. It does not decode media or emulate browser timing.
+export function audioHost(t) {
+  const instances = []
+  const warnings = []
+  let play = () => Promise.resolve()
+  class Audio {
+    constructor() {
+      instances.push(this)
+      this.calls = []
+      this.paused = true
+      for (const [name, initial] of Object.entries({ src: '', preload: '', currentTime: 0, playbackRate: 1, volume: 1, muted: false })) {
+        let value = initial
+        Object.defineProperty(this, name, {
+          get: () => value,
+          set: (next) => {
+            this.calls.push([name, next])
+            value = next
+          },
+        })
+      }
+    }
+
+    play() {
+      this.calls.push(['play'])
+      return play(this)
+    }
+
+    pause() { this.calls.push(['pause']) }
+    load() { this.calls.push(['load']) }
+  }
+  const descriptor = Object.getOwnPropertyDescriptor(globalThis, 'Audio')
+  Object.defineProperty(globalThis, 'Audio', { configurable: true, value: Audio })
+  t.after(() => descriptor ? Object.defineProperty(globalThis, 'Audio', descriptor) : Reflect.deleteProperty(globalThis, 'Audio'))
+  t.mock.method(console, 'warn', error => warnings.push(error))
+  return { ...createAudioArt(), instances, warnings, setPlay: callback => play = callback }
+}
+
+export function createAudioArt() {
+  const listeners = new Map()
+  const art = {
+    video: { playbackRate: 1.25 },
+    currentTime: 0,
+    playing: false,
+    volume: 0.6,
+    muted: false,
+    on(event, callback) {
+      if (!listeners.has(event))
+        listeners.set(event, new Set())
+      listeners.get(event).add(callback)
+      return art
+    },
+    off(event, callback) {
+      listeners.get(event)?.delete(callback)
+      return art
+    },
+    emit(event, ...args) {
+      for (const callback of [...(listeners.get(event) || [])])
+        callback(...args)
+      return art
+    },
+  }
+  return { art, listeners }
+}