Refine YouTube playback launch preparation

src/main/runtime/youtube-playback-launch.test.ts

@@ -18,7 +18,12 @@ test('prepare youtube playback skips load when current path already matches exac
   const ok = await prepare({ url: 'https://www.youtube.com/watch?v=abc123' });
 
   assert.equal(ok, true);
-  assert.deepEqual(commands, []);
+  assert.deepEqual(commands, [
+    ['set_property', 'pause', 'yes'],
+    ['set_property', 'sub-auto', 'no'],
+    ['set_property', 'sid', 'no'],
+    ['set_property', 'secondary-sid', 'no'],
+  ]);
 });
 
 test('prepare youtube playback treats matching video IDs as already loaded', async () => {
@@ -33,7 +38,12 @@ test('prepare youtube playback treats matching video IDs as already loaded', asy
   const ok = await prepare({ url: 'https://www.youtube.com/watch?v=abc123' });
 
   assert.equal(ok, true);
-  assert.deepEqual(commands, []);
+  assert.deepEqual(commands, [
+    ['set_property', 'pause', 'yes'],
+    ['set_property', 'sub-auto', 'no'],
+    ['set_property', 'sid', 'no'],
+    ['set_property', 'secondary-sid', 'no'],
+  ]);
 });
 
 test('prepare youtube playback does not mark matching target ready until tracks exist', async () => {
@@ -59,7 +69,12 @@ test('prepare youtube playback does not mark matching target ready until tracks
   });
 
   assert.equal(ok, true);
-  assert.deepEqual(commands, []);
+  assert.deepEqual(commands, [
+    ['set_property', 'pause', 'yes'],
+    ['set_property', 'sub-auto', 'no'],
+    ['set_property', 'sid', 'no'],
+    ['set_property', 'secondary-sid', 'no'],
+  ]);
 });
 
 test('prepare youtube playback replaces media and waits for path switch', async () => {
@@ -185,13 +200,17 @@ test('prepare youtube playback accepts a non-youtube resolved path once playable
   });
 
   const ok = await prepare({
-    url: 'https://www.youtube.com/watch?v=newvid',
+    url: 'https://rr16---sn.example.googlevideo.com/videoplayback?id=abc',
     timeoutMs: 1500,
     pollIntervalMs: 1,
   });
 
   assert.equal(ok, true);
-  assert.deepEqual(commands[4], ['loadfile', 'https://www.youtube.com/watch?v=newvid', 'replace']);
+  assert.deepEqual(commands[4], [
+    'loadfile',
+    'https://rr16---sn.example.googlevideo.com/videoplayback?id=abc',
+    'replace',
+  ]);
 });
 
 test('prepare youtube playback does not accept a different youtube video after path change', async () => {
@@ -234,3 +253,39 @@ test('prepare youtube playback does not accept a different youtube video after p
     'replace',
   ]);
 });
+
+test('prepare youtube playback accepts a fresh-start path change when the direct target matches exactly', async () => {
+  const commands: Array<Array<string>> = [];
+  const observedPaths = [
+    '',
+    'https://rr16---sn.example.googlevideo.com/videoplayback?id=abc',
+  ];
+  const observedTrackLists = [[], [{ type: 'video', id: 1 }, { type: 'audio', id: 2 }]];
+  let requestCount = 0;
+  const prepare = createPrepareYoutubePlaybackInMpvHandler({
+    requestPath: async () => {
+      const value = observedPaths[Math.min(requestCount, observedPaths.length - 1)] ?? null;
+      requestCount += 1;
+      return value;
+    },
+    requestProperty: async (name) => {
+      if (name !== 'track-list') return null;
+      return observedTrackLists[Math.min(requestCount - 1, observedTrackLists.length - 1)] ?? [];
+    },
+    sendMpvCommand: (command) => commands.push(command),
+    wait: createWaitStub(),
+  });
+
+  const ok = await prepare({
+    url: 'https://rr16---sn.example.googlevideo.com/videoplayback?id=abc',
+    timeoutMs: 1500,
+    pollIntervalMs: 1,
+  });
+
+  assert.equal(ok, true);
+  assert.deepEqual(commands[4], [
+    'loadfile',
+    'https://rr16---sn.example.googlevideo.com/videoplayback?id=abc',
+    'replace',
+  ]);
+});

src/main/runtime/youtube-playback-launch.ts

@@ -79,6 +79,13 @@ function hasPlayableMediaTracks(trackListRaw: unknown): boolean {
   });
 }
 
+function sendPlaybackPrepCommands(sendMpvCommand: (command: Array<string>) => void): void {
+  sendMpvCommand(['set_property', 'pause', 'yes']);
+  sendMpvCommand(['set_property', 'sub-auto', 'no']);
+  sendMpvCommand(['set_property', 'sid', 'no']);
+  sendMpvCommand(['set_property', 'secondary-sid', 'no']);
+}
+
 export function createPrepareYoutubePlaybackInMpvHandler(deps: YoutubePlaybackLaunchDeps) {
   const now = deps.now ?? (() => Date.now());
   return async (input: YoutubePlaybackLaunchInput): Promise<boolean> => {
@@ -95,6 +102,8 @@ export function createPrepareYoutubePlaybackInMpvHandler(deps: YoutubePlaybackLa
       // Ignore transient path request failures and continue with bootstrap commands.
     }
 
+    sendPlaybackPrepCommands(deps.sendMpvCommand);
+
     const alreadyTarget = pathMatchesYoutubeTarget(previousPath, targetUrl);
     if (alreadyTarget) {
       if (!deps.requestProperty) {
@@ -109,10 +118,6 @@ export function createPrepareYoutubePlaybackInMpvHandler(deps: YoutubePlaybackLa
         // Keep polling; mpv can report the target path before tracks are ready.
       }
     } else {
-      deps.sendMpvCommand(['set_property', 'pause', 'yes']);
-      deps.sendMpvCommand(['set_property', 'sub-auto', 'no']);
-      deps.sendMpvCommand(['set_property', 'sid', 'no']);
-      deps.sendMpvCommand(['set_property', 'secondary-sid', 'no']);
       deps.sendMpvCommand(['loadfile', targetUrl, 'replace']);
     }
 
@@ -139,12 +144,13 @@ export function createPrepareYoutubePlaybackInMpvHandler(deps: YoutubePlaybackLa
           // Continue polling until media tracks are actually available.
         }
       }
-      if (previousPath && currentPath !== previousPath) {
+      const pathChanged = currentPath !== previousPath;
-        if (isYoutubeMediaPath(currentPath) && isYoutubeMediaPath(targetUrl)) {
+      const matchesChangedTarget =
-          if (!pathMatchesYoutubeTarget(currentPath, targetUrl)) {
+        currentPath === targetUrl ||
-            continue;
+        (isYoutubeMediaPath(currentPath) &&
-          }
+          isYoutubeMediaPath(targetUrl) &&
-        }
+          pathMatchesYoutubeTarget(currentPath, targetUrl));
+      if (pathChanged && matchesChangedTarget) {
         if (deps.requestProperty) {
           try {
             const trackList = await deps.requestProperty('track-list');