fix: a/b test 20: music continuation item renderer

codegen/src/abtest.rs

@@ -39,10 +39,14 @@ pub enum ABTest {
     ChannelPlaylistsLockup = 17,
     MusicPlaylistFacepile = 18,
     MusicAlbumGroupsReordered = 19,
+    MusicContinuationItemRenderer = 20,
 }
 
 /// List of active A/B tests that are run when none is manually specified
-const TESTS_TO_RUN: &[ABTest] = &[ABTest::MusicAlbumGroupsReordered];
+const TESTS_TO_RUN: &[ABTest] = &[
+    ABTest::MusicAlbumGroupsReordered,
+    ABTest::MusicContinuationItemRenderer,
+];
 
 #[derive(Debug, Serialize, Deserialize)]
 pub struct ABTestRes {
@@ -114,6 +118,9 @@ pub async fn run_test(
                     ABTest::ChannelPlaylistsLockup => channel_playlists_lockup(&query).await,
                     ABTest::MusicPlaylistFacepile => music_playlist_facepile(&query).await,
                     ABTest::MusicAlbumGroupsReordered => music_album_groups_reordered(&query).await,
+                    ABTest::MusicContinuationItemRenderer => {
+                        music_continuation_item_renderer(&query).await
+                    }
                 }
                 .unwrap();
                 pb.inc(1);
@@ -421,3 +428,18 @@ pub async fn music_album_groups_reordered(rp: &RustyPipeQuery) -> Result<bool> {
         .await?;
     Ok(res.contains("\"Singles & EPs\""))
 }
+
+pub async fn music_continuation_item_renderer(rp: &RustyPipeQuery) -> Result<bool> {
+    let id = "VLPLbZIPy20-1pN7mqjckepWF78ndb6ci_qi";
+    let res = rp
+        .raw(
+            ClientType::DesktopMusic,
+            "browse",
+            &QBrowse {
+                browse_id: id,
+                params: None,
+            },
+        )
+        .await?;
+    Ok(res.contains("\"continuationItemRenderer\""))
+}

notes/AB_Tests.md

@@ -1034,5 +1034,21 @@ commandContext missing).
 
 YouTube Music used to group artist albums into 2 rows: "Albums" and "Singles".
 
-These groups were changed into "Albums" and "Singles & EPs". Now the "Album" label is omitted
+These groups were changed into "Albums" and "Singles & EPs". Now the "Album" label is
-for albums in their group, while singles and EPs have a label with their type.
+omitted for albums in their group, while singles and EPs have a label with their type.
+
+## [20] Music continuation item renderer
+
+- **Encountered on:** 25.01.2025
+- **Impact:** 🟢 Low
+- **Endpoint:** browse (YTM)
+- **Status:** Common (4%)
+
+YouTube Music now uses a `continuationItemRenderer` for music playlists instead of
+putting the continuations in a separate attribute of the MusicShelf.
+
+The continuation response now uses a `onResponseReceivedActions` field for its music
+items.
+
+YouTube Music now also sends a random 16-character string as a `clientScreenNonce` in
+the request context. This is not mandatory though.

src/client/music_playlist.rs

@@ -196,13 +196,15 @@ impl MapResponse<MusicPlaylist> for response::MusicPlaylist {
 
         let mut mapper = MusicListMapper::new(ctx.lang);
         mapper.map_response(shelf.contents);
-        let map_res = mapper.conv_items();
 
-        let ctoken = shelf
+        let ctoken = mapper.ctoken.clone().or_else(|| {
-            .continuations
+            shelf
-            .into_iter()
+                .continuations
-            .next()
+                .into_iter()
-            .map(|cont| cont.next_continuation_data.continuation);
+                .next()
+                .map(|cont| cont.next_continuation_data.continuation)
+        });
+        let map_res = mapper.conv_items();
 
         let track_count = if ctoken.is_some() {
             header.as_ref().and_then(|h| {

src/client/music_search.rs

@@ -189,6 +189,7 @@ impl<T: FromYtItem> MapResponse<MusicSearchResult<T>> for response::MusicSearch
             response::music_search::ItemSection::None => {}
         });
 
+        let ctoken = ctoken.or(mapper.ctoken.clone());
         let map_res = mapper.conv_items();
 
         Ok(MapResult {

src/client/pagination.rs

@@ -199,11 +199,17 @@ impl MapResponse<Paginator<MusicItem>> for response::MusicContinuation {
             None => {}
         }
 
+        for a in self.on_response_received_actions {
+            mapper.map_response(a.append_continuation_items_action.continuation_items);
+        }
+
+        let ctoken = mapper.ctoken.clone().or_else(|| {
+            continuations
+                .into_iter()
+                .next()
+                .map(|cont| cont.next_continuation_data.continuation)
+        });
         let map_res = mapper.items();
-        let ctoken = continuations
-            .into_iter()
-            .next()
-            .map(|cont| cont.next_continuation_data.continuation);
 
         Ok(MapResult {
             c: Paginator::new_ext(

src/client/response/music_item.rs

@@ -18,7 +18,8 @@ use super::{
     url_endpoint::{
         BrowseEndpointWrap, MusicPage, MusicPageType, MusicVideoType, NavigationEndpoint, PageType,
     },
-    ContentsRenderer, MusicContinuationData, SimpleHeaderRenderer, Thumbnails, ThumbnailsWrap,
+    ContentsRenderer, ContinuationActionWrap, ContinuationEndpoint, MusicContinuationData,
+    SimpleHeaderRenderer, Thumbnails, ThumbnailsWrap,
 };
 
 #[derive(Debug, Deserialize)]
@@ -86,6 +87,10 @@ pub(crate) enum MusicResponseItem {
     MusicResponsiveListItemRenderer(ListMusicItem),
     MusicTwoRowItemRenderer(CoverMusicItem),
     MessageRenderer(serde::de::IgnoredAny),
+    #[serde(rename_all = "camelCase")]
+    ContinuationItemRenderer {
+        continuation_endpoint: ContinuationEndpoint,
+    },
 }
 
 #[serde_as]
@@ -322,10 +327,14 @@ impl From<MusicThumbnailRenderer> for Vec<model::Thumbnail> {
 }
 
 /// Music list continuation response model
+#[serde_as]
 #[derive(Debug, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub(crate) struct MusicContinuation {
     pub continuation_contents: Option<ContinuationContents>,
+    #[serde(default)]
+    #[serde_as(as = "VecSkipError<_>")]
+    pub on_response_received_actions: Vec<ContinuationActionWrap<MusicResponseItem>>,
 }
 
 #[derive(Debug, Deserialize)]
@@ -434,6 +443,7 @@ pub(crate) struct MusicListMapper {
     search_suggestion: bool,
     items: Vec<MusicItem>,
     warnings: Vec<String>,
+    pub ctoken: Option<String>,
 }
 
 #[derive(Debug)]
@@ -455,6 +465,7 @@ impl MusicListMapper {
             search_suggestion: false,
             items: Vec::new(),
             warnings: Vec::new(),
+            ctoken: None,
         }
     }
 
@@ -468,6 +479,7 @@ impl MusicListMapper {
             search_suggestion: true,
             items: Vec::new(),
             warnings: Vec::new(),
+            ctoken: None,
         }
     }
 
@@ -482,6 +494,7 @@ impl MusicListMapper {
             search_suggestion: false,
             items: Vec::new(),
             warnings: Vec::new(),
+            ctoken: None,
         }
     }
 
@@ -496,6 +509,7 @@ impl MusicListMapper {
             search_suggestion: false,
             items: Vec::new(),
             warnings: Vec::new(),
+            ctoken: None,
         }
     }
 
@@ -507,6 +521,12 @@ impl MusicListMapper {
             // Tile
             MusicResponseItem::MusicTwoRowItemRenderer(item) => self.map_tile(item),
             MusicResponseItem::MessageRenderer(_) => Ok(None),
+            MusicResponseItem::ContinuationItemRenderer {
+                continuation_endpoint,
+            } => {
+                self.ctoken = Some(continuation_endpoint.continuation_command.token);
+                Ok(None)
+            }
         }
     }
 

src/client/search.rs

@@ -120,7 +120,7 @@ impl<T: FromYtItem> MapResponse<SearchResult<T>> for response::Search {
                         .filter_map(T::from_yt_item)
                         .collect(),
                     mapper.ctoken,
-                    None,
+                    ctx.visitor_data.map(str::to_owned),
                     ContinuationEndpoint::Search,
                     false,
                 ),

src/client/video_details.rs

@@ -277,7 +277,7 @@ impl MapResponse<VideoDetails> for response::VideoDetails {
                         r,
                         sr.secondary_results.continuations,
                         visitor_data.clone(),
-                        ctx.lang,
+                        ctx,
                     );
                     warnings.append(&mut res.warnings);
                     res.c
@@ -359,7 +359,7 @@ impl MapResponse<VideoDetails> for response::VideoDetails {
                     comment_ctoken,
                     visitor_data.clone(),
                     ContinuationEndpoint::Next,
-                    false,
+                    ctx.authenticated,
                 ),
                 latest_comments: Paginator::new_ext(
                     comment_count,
@@ -367,7 +367,7 @@ impl MapResponse<VideoDetails> for response::VideoDetails {
                     latest_comments_ctoken,
                     visitor_data.clone(),
                     ContinuationEndpoint::Next,
-                    false,
+                    ctx.authenticated,
                 ),
                 visitor_data,
             },
@@ -468,9 +468,9 @@ fn map_recommendations(
     r: MapResult<Vec<response::YouTubeListItem>>,
     continuations: Option<Vec<response::MusicContinuationData>>,
     visitor_data: Option<String>,
-    lang: Language,
+    ctx: &MapRespCtx<'_>,
 ) -> MapResult<Paginator<VideoItem>> {
-    let mut mapper = response::YouTubeListMapper::<VideoItem>::new(lang);
+    let mut mapper = response::YouTubeListMapper::<VideoItem>::new(ctx.lang);
     mapper.map_response(r);
 
     mapper.ctoken = mapper.ctoken.or_else(|| {
@@ -486,7 +486,7 @@ fn map_recommendations(
             mapper.ctoken,
             visitor_data,
             ContinuationEndpoint::Next,
-            false,
+            ctx.authenticated,
         ),
         warnings: mapper.warnings,
     }