Restore native boot scheduling without an extra core request

frontend/app-bootstrap.js

@@ -1,65 +0,0 @@
-/* Cache the single page-owned app response before it registers the worker. */
-(function (root) {
-  'use strict';
-  const doc=root.document, manifest=root.Lazy.manifest, key=root.Lazy.url('/app.js');
-  let domReady=doc.readyState==='complete', appSawDom=false;
-  doc.addEventListener('DOMContentLoaded',()=>{domReady=true;appSawDom=typeof root.boot==='function';},{once:true});
-  function execute(node) {
-    doc.head.append(node);
-    node.remove();
-    delete root.Lazy.appResponse;
-    // app.js keeps its original DOMContentLoaded listener. Async response
-    // consumption can finish after that event; boot exactly once in that case.
-    if(domReady)root.boot();
-  }
-  async function external(url) {
-    await new Promise((resolve,reject)=>{
-      const node=doc.createElement('script');node.src=url;
-      node.onload=()=>{if(domReady&&!appSawDom)root.boot();resolve();};node.onerror=()=>reject(Error('Unable to load player'));
-      doc.head.append(node);
-    });
-  }
-  async function verified(response, expected) {
-    const bytes=await response.clone().arrayBuffer();
-    const digest=new Uint8Array(await root.crypto.subtle.digest('SHA-256',bytes));
-    const hex=Array.from(digest,b=>b.toString(16).padStart(2,'0')).join('');
-    if(hex.slice(0,10)!==expected)throw Error('Player body hash mismatch');
-    return {bytes,digest};
-  }
-  async function start() {
-    if(!manifest.appCache || !root.crypto?.subtle || !root.Lazy.captureApp)return external(key);
-    const expected=manifest.files['/app.js'].h;
-    let cache;
-    try { cache=await root.caches?.open('ytplayer-assets'); } catch {}
-    let response=await cache?.match(key);
-    if(!response || response.headers.get('X-Asset-Hash')!==expected) {
-      try { response=await (root.Lazy.appResponse || root.fetch(key,{credentials:'same-origin'})); } catch {}
-    }
-    if(!response?.ok || response.headers.get('X-Asset-Hash')!==expected) {
-      // Preserve staged N-1 boot after an individual cache eviction. Only the
-      // controller can serve this old URL safely; never fetch stale URLs bare.
-      const state=cache && await root.AssetSyncCore.state(cache);
-      const previousKey=state && root.AssetSyncCore.fallback(manifest,state.previous,'/app.js');
-      const previous=previousKey && await cache.match(previousKey);
-      const previousHash=state?.previous?.files['/app.js']?.h;
-      const contractsMatch=state?.previous && Object.entries(manifest.groups).every(([name,group])=>state.previous.groups[name]?.contract===group.contract);
-      if(contractsMatch && root.navigator?.serviceWorker?.controller && previous?.ok && previous.headers.get('X-Asset-Hash')===previousHash) {
-        await verified(previous,previousHash);
-        delete root.Lazy.appResponse;
-        return external(previousKey);
-      }
-      throw Error('Player asset hash mismatch');
-    }
-    const {bytes,digest}=await verified(response,expected);
-    const permission="'sha256-"+root.btoa(String.fromCharCode(...digest))+"'";
-    if(!doc.querySelector('meta[http-equiv="Content-Security-Policy"]').content.includes(permission))throw Error('Player body hash mismatch');
-    // CacheStorage may share a full quota with saved music. Never remove data
-    // to make room; boot from these verified bytes even if caching is refused.
-    try { await cache?.put(key,response); } catch(error) { root.console.warn('[app-cache]',error.message); }
-    const node=doc.createElement('script');node.textContent=new root.TextDecoder().decode(bytes);
-    execute(node);
-  }
-  const ready=start();
-  root.AppBootstrap={ready};
-  ready.catch(error=>root.console.error('[app-cache]',error.message));
-})(typeof window!=='undefined'?window:globalThis);

frontend/app-bootstrap.test.js

@@ -3,18 +3,18 @@ const assert=require('node:assert/strict');
 const {webcrypto,createHash}=require('node:crypto');
 const vm=require('node:vm');
 const {readFileSync}=require('node:fs');
-function fixture({cached=false,tampered=false,enabled=true,loading=false,quota=false,insecure=false,previous=false,contract=1,capture=true,controller=true}={}){
+function fixture({cached=false,tampered=false,enabled=true,loading=false,quota=false,insecure=false,previous=false,contract=1,capture=true,controller=true,parser=false}={}){
  const source='window.appRuns=(window.appRuns||0)+1; window.boot=()=>window.bootRuns=(window.bootRuns||0)+1; document.addEventListener("DOMContentLoaded",boot);',hash=createHash('sha256').update(source).digest('hex'), key='/app.js?v='+hash.slice(0,10);
  const oldSource='window.oldApp=true;'+source, oldHash=createHash('sha256').update(oldSource).digest('hex').slice(0,10), oldKey='/app.js?v='+oldHash;
- const held=new Map(), appended=[],listeners={};let calls=0;
+ const held=new Map(), appended=[],writes=[],listeners={};let calls=0;
  const response=()=>new Response(tampered?'bad':source,{headers:{'X-Asset-Hash':hash.slice(0,10)}});
  if(cached)held.set(key,response());
  if(previous){held.set(oldKey,new Response(oldSource,{headers:{'X-Asset-Hash':oldHash}}));held.set('/__ytp_asset_state',Response.json({previous:{files:{'/app.js':{h:oldHash}},groups:{core:{contract,files:['/app.js']}}}}));}
  const root={crypto:insecure?undefined:webcrypto,TextDecoder,Uint8Array,btoa,console,AssetSyncCore:require('./asset-sync-core'),navigator:{serviceWorker:{controller:controller?{}:null}},Lazy:{captureApp:capture,manifest:{groups:{core:{contract:1,files:['/app.js']}},appCache:enabled,files:{'/app.js':{h:hash.slice(0,10)}}},url:()=>key},fetch:async()=>{calls++;return previous?new Response(oldSource,{headers:{'X-Asset-Hash':oldHash}}):response();},caches:{open:async()=>({match:async k=>held.get(k)?.clone(),put:async(k,r)=>{if(quota)throw Error('quota');held.set(k,r.clone());}})}};
- const doc=root.document={readyState:loading?'loading':'complete',querySelector:()=>({content:"script-src 'self' 'sha256-"+Buffer.from(hash,'hex').toString('base64')+"'"}),addEventListener:(name,fn)=>(listeners[name] ||= []).push(fn),createElement:()=>({remove(){this.removed=true;}}),head:{append(node){appended.push(node);if(node.textContent)vm.runInContext(node.textContent,context);else {queueMicrotask(async()=>{if(previous && node.src===key){const state=await held.get('/__ytp_asset_state').clone().json();if(!root.AssetSyncCore.fallback(root.Lazy.manifest,state.previous,'/app.js'))return node.onerror();vm.runInContext(oldSource,context);}else vm.runInContext(node.src===oldKey?oldSource:source,context);node.onload();});}}}};
+ const doc=root.document={readyState:loading?'loading':'complete',currentScript:parser?{}:null,write:value=>{writes.push(value);vm.runInContext(source,context);},querySelector:()=>({content:"script-src 'self' 'sha256-"+Buffer.from(hash,'hex').toString('base64')+"'"}),addEventListener:(name,fn)=>(listeners[name] ||= []).push(fn),createElement:()=>({remove(){this.removed=true;}}),head:{append(node){appended.push(node);if(node.textContent)vm.runInContext(node.textContent,context);else {queueMicrotask(async()=>{if(previous && node.src===key){const state=await held.get('/__ytp_asset_state').clone().json();if(!root.AssetSyncCore.fallback(root.Lazy.manifest,state.previous,'/app.js'))return node.onerror();vm.runInContext(oldSource,context);}else vm.runInContext(node.src===oldKey?oldSource:source,context);node.onload();});}}}};
  root.window=root;const context=vm.createContext(root);
- vm.runInContext(readFileSync(require.resolve('./app-bootstrap.js'),'utf8'),context);
- return {root,held,appended,listeners,key,calls:()=>calls,doc,response,oldKey};
+ vm.runInContext(readFileSync(require.resolve('./section-rail.js'),'utf8'),context);
+ return {root,held,appended,writes,listeners,key,calls:()=>calls,doc,response,oldKey};
 }
 test('cold boot caches verified app before execution so worker skips its download',async()=>{
  const f=fixture();await f.root.AppBootstrap.ready;assert.equal(f.calls(),1);assert.ok(f.held.has(f.key));assert.equal(f.root.appRuns,1);assert.equal(f.root.bootRuns,1);assert.equal(f.appended[0].src,undefined);assert.equal(f.appended[0].removed,true);
@@ -74,3 +74,11 @@ test('native-cache engines still reject an incompatible retained core',async()=>
 test('native-cache engines use the validated current cache entry without decoding its body',async()=>{
  const f=fixture({capture:false,cached:true});await f.root.AppBootstrap.ready;assert.equal(f.calls(),0);assert.equal(f.appended[0].src,f.key);assert.equal(f.root.bootRuns,1);
 });
+
+test('native parser boot preserves classic evaluation before the original DOM event',async()=>{
+ const f=fixture({capture:false,loading:true,parser:true});
+ assert.equal(f.root.appRuns,1);assert.equal(f.root.bootRuns,undefined);
+ assert.deepEqual(f.writes,['<script src="'+f.key+'"></script>']);assert.equal(f.appended.length,0);
+ for(const fn of f.listeners.DOMContentLoaded)fn();await f.root.AppBootstrap.ready;
+ assert.equal(f.root.bootRuns,1);assert.equal(f.calls(),0);
+});

frontend/app-seams.test.js

@@ -30,8 +30,8 @@ test('Phase 4 preserves the exact player, continuity, tracking and queue bodies'
 test('eager shell and Settings definitions load before app state and defer reading it',()=>{
  const html=readFileSync(join(__dirname,'index.html'),'utf8');
  for(const file of ['shell-core.js','views-core.js','section-rail.js']) {
-  assert.ok(html.indexOf('src="'+file+'"')<html.indexOf('src="app-bootstrap.js"'));
-  const vm=require('node:vm');const context=vm.createContext({window:{},document:{}});
+  assert.ok(html.indexOf('src="'+file+'"')<=html.indexOf('src="section-rail.js"'));
+  const vm=require('node:vm');const doc={readyState:'complete',addEventListener(){},createElement:()=>({}),head:{append(){}}};const globals={document:doc,Lazy:{manifest:{appCache:false},url:()=>'/app.js'},console};globals.window=globals;const context=vm.createContext(globals);
   // Evaluation before any data/$/els/Player declaration must be safe.
   vm.runInContext(readFileSync(join(__dirname,file),'utf8'),context);
  }

frontend/assets.json

@@ -1,7 +1,7 @@
 {
   "groups": {
     "core": {
-      "contract": 1,
+      "contract": 2,
       "eager": true,
       "files": [
         "/index.html",
@@ -60,8 +60,7 @@
         "/device-db.js",
         "/shell-core.js",
         "/views-core.js",
-        "/section-rail.js",
-        "/app-bootstrap.js"
+        "/section-rail.js"
       ],
       "background": false
     },

frontend/lazy.js

@@ -138,7 +138,7 @@
     api.appResponse.catch(()=>{});
   } else if(manifest.appCache) {
     // Preserve native script/code-cache reuse in engines without the WebKit gap.
-    const preload=doc.createElement('link');preload.rel='preload';preload.as='script';preload.href=url('/app.js');doc.head.append(preload);
+    const preload=doc.createElement('link');preload.rel='preload';preload.as='script';preload.fetchPriority='low';preload.href=url('/app.js');doc.head.append(preload);
   }
   root.Lazy = api;
   root.navigator.serviceWorker?.addEventListener('message',event=>{

frontend/lazy.test.js

@@ -102,7 +102,7 @@ test('head capture is cache-first even before a worker controls the page',async(
 test('Chromium retains native script loading and only preloads the current app URL',async()=>{
  const f=fixture(null,[],true,'AppleWebKit/537.36 Chrome/140.0 Safari/537.36');
  assert.equal(f.root.Lazy.captureApp,false);assert.equal(f.root.Lazy.appResponse,undefined);assert.deepEqual(f.fetched,[]);
- assert.equal(f.inserted.length,1);assert.equal(f.inserted[0].rel,'preload');assert.equal(f.inserted[0].as,'script');assert.equal(f.inserted[0].href,'/app.js?v=a');
+ assert.equal(f.inserted.length,1);assert.equal(f.inserted[0].rel,'preload');assert.equal(f.inserted[0].as,'script');assert.equal(f.inserted[0].href,'/app.js?v=a');assert.equal(f.inserted[0].fetchPriority,'low');
 });
 test('iOS Chromium-branded browsers still use their WebKit response capture',async()=>{
  const f=fixture(null,[],true,'AppleWebKit/605.1 CriOS/140.0 Mobile Safari/605.1');await f.root.Lazy.appResponse;
@@ -112,5 +112,5 @@ test('iOS Chromium-branded browsers still use their WebKit response capture',asy
 test('controlled WebKit visits use worker-cached native app scripts without a response handoff',async()=>{
  const f=fixture(null,[],true,'AppleWebKit/605.1 Safari/605.1',true);
  assert.equal(f.root.Lazy.captureApp,false);assert.equal(f.root.Lazy.appResponse,undefined);assert.deepEqual(f.fetched,[]);
- assert.equal(f.inserted[0].as,'script');assert.equal(f.inserted[0].href,'/app.js?v=a');
+ assert.equal(f.inserted[0].as,'script');assert.equal(f.inserted[0].href,'/app.js?v=a');assert.equal(f.inserted[0].fetchPriority,'low');
 });

frontend/section-rail.js

@@ -245,3 +245,77 @@ const SectionRail = (() => {
 
   return { boot, refresh, setFolded, isFolded };
 })();
+
+/* Cache the single page-owned app response before it registers the worker. */
+(function (root) {
+  'use strict';
+  const doc=root.document, manifest=root.Lazy.manifest, key=root.Lazy.url('/app.js');
+  let domReady=doc.readyState==='complete', appSawDom=false;
+  doc.addEventListener('DOMContentLoaded',()=>{domReady=true;appSawDom=typeof root.boot==='function';},{once:true});
+  function execute(node) {
+    doc.head.append(node);
+    node.remove();
+    delete root.Lazy.appResponse;
+    // app.js keeps its original DOMContentLoaded listener. Async response
+    // consumption can finish after that event; boot exactly once in that case.
+    if(domReady)root.boot();
+  }
+  async function external(url) {
+    await new Promise((resolve,reject)=>{
+      const node=doc.createElement('script');node.src=url;
+      node.onload=()=>{if(domReady&&!appSawDom)root.boot();resolve();};node.onerror=()=>reject(Error('Unable to load player'));
+      doc.head.append(node);
+    });
+  }
+  function native() {
+    if(doc.readyState!=='loading' || !doc.currentScript)return external(key);
+    return new Promise((resolve,reject)=>{
+      doc.addEventListener('DOMContentLoaded',()=>typeof root.boot==='function'?resolve():reject(Error('Unable to load player')),{once:true});
+      const escaped=key.replaceAll('&','&amp;').replaceAll('"','&quot;').replaceAll('<','&lt;');
+      doc.write('<script src="'+escaped+'"></script>');
+    });
+  }
+  async function verified(response, expected) {
+    const bytes=await response.clone().arrayBuffer();
+    const digest=new Uint8Array(await root.crypto.subtle.digest('SHA-256',bytes));
+    const hex=Array.from(digest,b=>b.toString(16).padStart(2,'0')).join('');
+    if(hex.slice(0,10)!==expected)throw Error('Player body hash mismatch');
+    return {bytes,digest};
+  }
+  async function start() {
+    if(!manifest.appCache || !root.crypto?.subtle || !root.Lazy.captureApp)return native();
+    const expected=manifest.files['/app.js'].h;
+    let cache;
+    try { cache=await root.caches?.open('ytplayer-assets'); } catch {}
+    let response=await cache?.match(key);
+    if(!response || response.headers.get('X-Asset-Hash')!==expected) {
+      try { response=await (root.Lazy.appResponse || root.fetch(key,{credentials:'same-origin'})); } catch {}
+    }
+    if(!response?.ok || response.headers.get('X-Asset-Hash')!==expected) {
+      // Preserve staged N-1 boot after an individual cache eviction. Only the
+      // controller can serve this old URL safely; never fetch stale URLs bare.
+      const state=cache && await root.AssetSyncCore.state(cache);
+      const previousKey=state && root.AssetSyncCore.fallback(manifest,state.previous,'/app.js');
+      const previous=previousKey && await cache.match(previousKey);
+      const previousHash=state?.previous?.files['/app.js']?.h;
+      const contractsMatch=state?.previous && Object.entries(manifest.groups).every(([name,group])=>state.previous.groups[name]?.contract===group.contract);
+      if(contractsMatch && root.navigator?.serviceWorker?.controller && previous?.ok && previous.headers.get('X-Asset-Hash')===previousHash) {
+        await verified(previous,previousHash);
+        delete root.Lazy.appResponse;
+        return external(previousKey);
+      }
+      throw Error('Player asset hash mismatch');
+    }
+    const {bytes,digest}=await verified(response,expected);
+    const permission="'sha256-"+root.btoa(String.fromCharCode(...digest))+"'";
+    if(!doc.querySelector('meta[http-equiv="Content-Security-Policy"]').content.includes(permission))throw Error('Player body hash mismatch');
+    // CacheStorage may share a full quota with saved music. Never remove data
+    // to make room; boot from these verified bytes even if caching is refused.
+    try { await cache?.put(key,response); } catch(error) { root.console.warn('[app-cache]',error.message); }
+    const node=doc.createElement('script');node.textContent=new root.TextDecoder().decode(bytes);
+    execute(node);
+  }
+  const ready=start();
+  root.AppBootstrap={ready};
+  ready.catch(error=>root.console.error('[app-cache]',error.message));
+})(typeof window!=='undefined'?window:globalThis);

frontend/shell-consistency.test.js

@@ -32,7 +32,7 @@ test('assets.json describes the complete existing shell exactly once with eager
   const { groups } = JSON.parse(readFileSync(join(__dirname, 'assets.json'), 'utf8'));
   const described = new Set();
   for (const [name, group] of Object.entries(groups)) {
-    assert.equal(group.contract, 1, `${name} initial contract`);
+    assert.equal(group.contract, name === 'core' ? 2 : 1, `${name} contract (core boot packing changed)`);
     assert.equal(typeof group.eager, 'boolean');
     for (const asset of group.files) {
       assert.ok(!described.has(asset), `${asset} has one group`);
@@ -100,12 +100,15 @@ test('classic first-visit style preload is discovered before the head loader wit
 });
 
 
-test('the eager cache bootstrap stays last and retains app.js in core and legacy shell',()=>{
+test('the last core script owns boot without an extra request or unsafe stale packing',()=>{
  const {groups}=JSON.parse(readFileSync(join(__dirname,'assets.json'),'utf8'));
- assert.ok(groups.core.files.includes('/app-bootstrap.js'));
+ assert.equal(groups.core.contract,2,'old core packing cannot fall back without the loader');
  assert.ok(groups.core.files.includes('/app.js'));
- assert.ok(listed.has('/app-bootstrap.js')&&listed.has('/app.js'));
- assert.ok(html.indexOf('src="app-bootstrap.js"')>html.indexOf('src="section-rail.js"'));
+ assert.ok(groups.core.files.includes('/section-rail.js'));
+ assert.equal(groups.core.files.includes('/app-bootstrap.js'),false);
+ assert.equal(listed.has('/app-bootstrap.js'),false);
+ const scripts=[...html.matchAll(/<script src="([^"]+)"/g)].map(m=>m[1]);
+ assert.equal(scripts.at(-1),'section-rail.js');
  assert.ok(html.includes("'sha256-__APP_SCRIPT_HASH__'"));
- assert.ok(readFileSync(join(__dirname,'lazy.js'),'utf8').includes("api.appResponse=(async()=>"));
+ assert.ok(readFileSync(join(__dirname,'section-rail.js'),'utf8').includes('root.AppBootstrap={ready}'));
 });

frontend/sw.js

@@ -146,7 +146,6 @@ const SHELL = [
   '/share-external.js',
   '/stats-view.js',
   '/app.js',
-  '/app-bootstrap.js',
   '/manifest.webmanifest',
   '/icons/icon-192.png',
   '/icons/icon-512.png',