feat: Add support for retrieving transcripts (#500)

* feat: Add support for retrieving transcripts

* chore: lint

* chore: update docs

* chore: Do not include nodes in errors thrown

* chore: Improve error messages

* fix(ExpandableMetadata): `expanded_content` type mismatch

* chore: lint

src/Innertube.ts

@@ -14,6 +14,8 @@ import NotificationsMenu from './parser/youtube/NotificationsMenu.js';
 import Playlist from './parser/youtube/Playlist.js';
 import Search from './parser/youtube/Search.js';
 import VideoInfo from './parser/youtube/VideoInfo.js';
+import ContinuationItem from './parser/classes/ContinuationItem.js';
+import Transcript from './parser/classes/Transcript.js';
 
 import { Kids, Music, Studio } from './core/clients/index.js';
 import { AccountManager, InteractionManager, PlaylistManager } from './core/managers/index.js';
@@ -36,7 +38,7 @@ import {
 import { GetUnseenCountEndpoint } from './core/endpoints/notification/index.js';
 
 import type { ApiResponse } from './core/Actions.js';
-import type { IBrowseResponse, IParsedResponse } from './parser/types/index.js';
+import { type IGetTranscriptResponse, type IBrowseResponse, type IParsedResponse } from './parser/types/index.js';
 import type { INextRequest } from './types/index.js';
 import type { DownloadOptions, FormatOptions } from './types/FormatUtils.js';
 
@@ -332,6 +334,35 @@ export default class Innertube {
     return info.chooseFormat(options);
   }
 
+  /**
+   * Retrieves a video's transcript.
+   * @param video_id - The video id.
+   */
+  async getTranscript(video_id: string): Promise<Transcript> {
+    throwIfMissing({ video_id });
+
+    const next_response = await this.actions.execute(NextEndpoint.PATH, { ...NextEndpoint.build({ video_id }), parse: true });
+
+    if (!next_response.engagement_panels)
+      throw new InnertubeError('Engagement panels not found. Video likely has no transcript.');
+
+    const transcript_panel = next_response.engagement_panels.get({
+      panel_identifier: 'engagement-panel-searchable-transcript'
+    });
+
+    if (!transcript_panel)
+      throw new InnertubeError('Transcript panel not found. Video likely has no transcript.');
+
+    const transcript_continuation = transcript_panel.content?.as(ContinuationItem);
+
+    if (!transcript_continuation)
+      throw new InnertubeError('Transcript continuation not found.');
+
+    const transcript_response = await transcript_continuation.endpoint.call<IGetTranscriptResponse>(this.actions, { parse: true });
+
+    return transcript_response.actions_memo.getType(Transcript).first();
+  }
+
   /**
    * Downloads a given video. If you only need the direct download link see {@link getStreamingData}.
    * If you wish to retrieve the video info too, have a look at {@link getBasicInfo} or {@link getInfo}.

src/parser/classes/EngagementPanelSectionList.ts

@@ -3,6 +3,7 @@ import Parser, { type RawNode } from '../index.js';
 import ContinuationItem from './ContinuationItem.js';
 import EngagementPanelTitleHeader from './EngagementPanelTitleHeader.js';
 import MacroMarkersList from './MacroMarkersList.js';
+import ProductList from './ProductList.js';
 import SectionList from './SectionList.js';
 import StructuredDescriptionContent from './StructuredDescriptionContent.js';
 
@@ -10,7 +11,7 @@ export default class EngagementPanelSectionList extends YTNode {
   static type = 'EngagementPanelSectionList';
 
   header: EngagementPanelTitleHeader | null;
-  content: SectionList | ContinuationItem | StructuredDescriptionContent | MacroMarkersList | null;
+  content: SectionList | ContinuationItem | StructuredDescriptionContent | MacroMarkersList | ProductList | null;
   target_id?: string;
   panel_identifier?: string;
   visibility?: string;
@@ -18,9 +19,9 @@ export default class EngagementPanelSectionList extends YTNode {
   constructor(data: RawNode) {
     super();
     this.header = Parser.parseItem(data.header, EngagementPanelTitleHeader);
-    this.content = Parser.parseItem(data.content, [ SectionList, ContinuationItem, StructuredDescriptionContent, MacroMarkersList ]);
+    this.content = Parser.parseItem(data.content, [ SectionList, ContinuationItem, StructuredDescriptionContent, MacroMarkersList, ProductList ]);
     this.panel_identifier = data.panelIdentifier;
     this.target_id = data.targetId;
     this.visibility = data.visibility;
   }
-}
+}

src/parser/classes/ExpandableMetadata.ts

@@ -2,6 +2,7 @@ import { YTNode } from '../helpers.js';
 import Parser, { type RawNode } from '../index.js';
 import Button from './Button.js';
 import HorizontalCardList from './HorizontalCardList.js';
+import HorizontalList from './HorizontalList.js';
 import Text from './misc/Text.js';
 import Thumbnail from './misc/Thumbnail.js';
 
@@ -15,7 +16,7 @@ export default class ExpandableMetadata extends YTNode {
     expanded_title: Text;
   };
 
-  expanded_content: HorizontalCardList | null;
+  expanded_content: HorizontalCardList | HorizontalList | null;
   expand_button: Button | null;
   collapse_button: Button | null;
 
@@ -31,7 +32,7 @@ export default class ExpandableMetadata extends YTNode {
       };
     }
 
-    this.expanded_content = Parser.parseItem(data.expandedContent, HorizontalCardList);
+    this.expanded_content = Parser.parseItem(data.expandedContent, [ HorizontalCardList, HorizontalList ]);
     this.expand_button = Parser.parseItem(data.expandButton, Button);
     this.collapse_button = Parser.parseItem(data.collapseButton, Button);
   }

src/parser/classes/FancyDismissibleDialog.ts

@@ -0,0 +1,16 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import { Text } from '../misc.js';
+
+export default class FancyDismissibleDialog extends YTNode {
+  static type = 'FancyDismissibleDialog';
+
+  dialog_message: Text;
+  confirm_label: Text;
+
+  constructor(data: RawNode) {
+    super();
+    this.dialog_message = new Text(data.dialogMessage);
+    this.confirm_label = new Text(data.confirmLabel);
+  }
+}

src/parser/classes/ProductList.ts

@@ -0,0 +1,15 @@
+import type { ObservedArray} from '../helpers.js';
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import Parser from '../index.js';
+
+export default class ProductList extends YTNode {
+  static type = 'ProductList';
+
+  contents: ObservedArray<YTNode>;
+
+  constructor(data: RawNode) {
+    super();
+    this.contents = Parser.parseArray(data.contents);
+  }
+}

src/parser/classes/ProductListHeader.ts

@@ -0,0 +1,16 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import { Text } from '../misc.js';
+
+export default class ProductListHeader extends YTNode {
+  static type = 'ProductListHeader';
+
+  title: Text;
+  suppress_padding_disclaimer: boolean;
+
+  constructor(data: RawNode) {
+    super();
+    this.title = new Text(data.title);
+    this.suppress_padding_disclaimer = !!data.suppressPaddingDisclaimer;
+  }
+}

src/parser/classes/ProductListItem.ts

@@ -0,0 +1,31 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import Parser from '../index.js';
+import { Text, Thumbnail } from '../misc.js';
+import Button from './Button.js';
+import NavigationEndpoint from './NavigationEndpoint.js';
+
+export default class ProductListItem extends YTNode {
+  static type = 'ProductListItem';
+
+  title: Text;
+  accessibility_title: string;
+  thumbnail: Thumbnail[];
+  price: string;
+  endpoint: NavigationEndpoint;
+  merchant_name: string;
+  stay_in_app: boolean;
+  view_button: Button | null;
+
+  constructor(data: RawNode) {
+    super();
+    this.title = new Text(data.title);
+    this.accessibility_title = data.accessibilityTitle;
+    this.thumbnail = Thumbnail.fromResponse(data.thumbnail);
+    this.price = data.price;
+    this.endpoint = new NavigationEndpoint(data.onClickCommand);
+    this.merchant_name = data.merchantName;
+    this.stay_in_app = !!data.stayInApp;
+    this.view_button = Parser.parseItem(data.viewButton, Button);
+  }
+}

src/parser/classes/StructuredDescriptionContent.ts

@@ -5,11 +5,15 @@ import HorizontalCardList from './HorizontalCardList.js';
 import VideoDescriptionHeader from './VideoDescriptionHeader.js';
 import VideoDescriptionInfocardsSection from './VideoDescriptionInfocardsSection.js';
 import VideoDescriptionMusicSection from './VideoDescriptionMusicSection.js';
+import type VideoDescriptionTranscriptSection from './VideoDescriptionTranscriptSection.js';
 
 export default class StructuredDescriptionContent extends YTNode {
   static type = 'StructuredDescriptionContent';
 
-  items: ObservedArray<VideoDescriptionHeader | ExpandableVideoDescriptionBody | VideoDescriptionMusicSection | VideoDescriptionInfocardsSection | HorizontalCardList>;
+  items: ObservedArray<
+    VideoDescriptionHeader | ExpandableVideoDescriptionBody | VideoDescriptionMusicSection |
+    VideoDescriptionInfocardsSection | VideoDescriptionTranscriptSection | HorizontalCardList
+  >;
 
   constructor(data: RawNode) {
     super();

src/parser/classes/Transcript.ts

@@ -0,0 +1,15 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import Parser from '../index.js';
+import TranscriptSearchPanel from './TranscriptSearchPanel.js';
+
+export default class Transcript extends YTNode {
+  static type = 'Transcript';
+
+  content: TranscriptSearchPanel | null;
+
+  constructor(data: RawNode) {
+    super();
+    this.content = Parser.parseItem(data.content, TranscriptSearchPanel);
+  }
+}

src/parser/classes/TranscriptFooter.ts

@@ -0,0 +1,15 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import Parser from '../index.js';
+import SortFilterSubMenu from './SortFilterSubMenu.js';
+
+export default class TranscriptFooter extends YTNode {
+  static type = 'TranscriptFooter';
+
+  language_menu: SortFilterSubMenu | null;
+
+  constructor(data: RawNode) {
+    super();
+    this.language_menu = Parser.parseItem(data.languageMenu, SortFilterSubMenu);
+  }
+}

src/parser/classes/TranscriptSearchBox.ts

@@ -0,0 +1,23 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import Parser from '../index.js';
+import Button from './Button.js';
+import NavigationEndpoint from './NavigationEndpoint.js';
+import { Text } from '../misc.js';
+
+export default class TranscriptSearchBox extends YTNode {
+  static type = 'TranscriptSearchBox';
+
+  formatted_placeholder: Text;
+  clear_button: Button | null;
+  endpoint: NavigationEndpoint;
+  search_button: Button | null;
+
+  constructor(data: RawNode) {
+    super();
+    this.formatted_placeholder = new Text(data.formattedPlaceholder);
+    this.clear_button = Parser.parseItem(data.clearButton, Button);
+    this.endpoint = new NavigationEndpoint(data.onTextChangeCommand);
+    this.search_button = Parser.parseItem(data.searchButton, Button);
+  }
+}

src/parser/classes/TranscriptSearchPanel.ts

@@ -0,0 +1,23 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import Parser from '../index.js';
+import TranscriptFooter from './TranscriptFooter.js';
+import TranscriptSearchBox from './TranscriptSearchBox.js';
+import TranscriptSegmentList from './TranscriptSegmentList.js';
+
+export default class TranscriptSearchPanel extends YTNode {
+  static type = 'TranscriptSearchPanel';
+
+  header: TranscriptSearchBox | null;
+  body: TranscriptSegmentList | null;
+  footer: TranscriptFooter | null;
+  target_id: string;
+
+  constructor(data: RawNode) {
+    super();
+    this.header = Parser.parseItem(data.header, TranscriptSearchBox);
+    this.body = Parser.parseItem(data.body, TranscriptSegmentList);
+    this.footer = Parser.parseItem(data.footer, TranscriptFooter);
+    this.target_id = data.targetId;
+  }
+}

src/parser/classes/TranscriptSegment.ts

@@ -0,0 +1,22 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import { Text } from '../misc.js';
+
+export default class TranscriptSegment extends YTNode {
+  static type = 'TranscriptSegment';
+
+  start_ms: string;
+  end_ms: string;
+  snippet: Text;
+  start_time_text: Text;
+  target_id: string;
+
+  constructor(data: RawNode) {
+    super();
+    this.start_ms = data.startMs;
+    this.end_ms = data.endMs;
+    this.snippet = new Text(data.snippet);
+    this.start_time_text = new Text(data.startTimeText);
+    this.target_id = data.targetId;
+  }
+}

src/parser/classes/TranscriptSegmentList.ts

@@ -0,0 +1,23 @@
+import type { ObservedArray} from '../helpers.js';
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import Parser from '../index.js';
+import { Text } from '../misc.js';
+import TranscriptSegment from './TranscriptSegment.js';
+
+export default class TranscriptSegmentList extends YTNode {
+  static type = 'TranscriptSegmentList';
+
+  initial_segments: ObservedArray<TranscriptSegment>;
+  no_result_label: Text;
+  retry_label: Text;
+  touch_captions_enabled: boolean;
+
+  constructor(data: RawNode) {
+    super();
+    this.initial_segments = Parser.parseArray(data.initialSegments, TranscriptSegment);
+    this.no_result_label = new Text(data.noResultLabel);
+    this.retry_label = new Text(data.retryLabel);
+    this.touch_captions_enabled = data.touchCaptionsEnabled;
+  }
+}

src/parser/classes/UploadTimeFactoid.ts

@@ -0,0 +1,15 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import Parser from '../index.js';
+import Factoid from './Factoid.js';
+
+export default class UploadTimeFactoid extends YTNode {
+  static type = 'UploadTimeFactoid';
+
+  factoid: Factoid | null;
+
+  constructor(data: RawNode) {
+    super();
+    this.factoid = Parser.parseItem(data.factoid, Factoid);
+  }
+}

src/parser/classes/VideoDescriptionHeader.ts

@@ -3,6 +3,8 @@ import Parser, { type RawNode } from '../index.js';
 import { Text, Thumbnail } from '../misc.js';
 import Factoid from './Factoid.js';
 import NavigationEndpoint from './NavigationEndpoint.js';
+import UploadTimeFactoid from './UploadTimeFactoid.js';
+import ViewCountFactoid from './ViewCountFactoid.js';
 
 export default class VideoDescriptionHeader extends YTNode {
   static type = 'VideoDescriptionHeader';
@@ -10,7 +12,7 @@ export default class VideoDescriptionHeader extends YTNode {
   channel: Text;
   channel_navigation_endpoint?: NavigationEndpoint;
   channel_thumbnail: Thumbnail[];
-  factoids: ObservedArray<Factoid>;
+  factoids: ObservedArray<Factoid | ViewCountFactoid | UploadTimeFactoid>;
   publish_date: Text;
   title: Text;
   views: Text;
@@ -23,6 +25,6 @@ export default class VideoDescriptionHeader extends YTNode {
     this.channel_thumbnail = Thumbnail.fromResponse(data.channelThumbnail);
     this.publish_date = new Text(data.publishDate);
     this.views = new Text(data.views);
-    this.factoids = Parser.parseArray(data.factoid, Factoid);
+    this.factoids = Parser.parseArray(data.factoid, [ Factoid, ViewCountFactoid, UploadTimeFactoid ]);
   }
 }

src/parser/classes/VideoDescriptionTranscriptSection.ts

@@ -0,0 +1,20 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import Parser from '../index.js';
+import { Text } from '../misc.js';
+import Button from './Button.js';
+
+export default class VideoDescriptionTranscriptSection extends YTNode {
+  static type = 'VideoDescriptionTranscriptSection';
+
+  section_title: Text;
+  sub_header_text: Text;
+  primary_button: Button | null;
+
+  constructor(data: RawNode) {
+    super();
+    this.section_title = new Text(data.sectionTitle);
+    this.sub_header_text = new Text(data.subHeaderText);
+    this.primary_button = Parser.parseItem(data.primaryButton, Button);
+  }
+}

src/parser/classes/ViewCountFactoid.ts

@@ -0,0 +1,19 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import Parser from '../index.js';
+import Factoid from './Factoid.js';
+
+export default class ViewCountFactoid extends YTNode {
+  static type = 'ViewCountFactoid';
+
+  view_count_entity_key: string;
+  factoid: Factoid | null;
+  view_count_type: string;
+
+  constructor(data: RawNode) {
+    super();
+    this.view_count_entity_key = data.viewCountEntityKey;
+    this.factoid = Parser.parseItem(data.factoid, [ Factoid ]);
+    this.view_count_type = data.viewCountType;
+  }
+}

src/parser/classes/actions/UpdateEngagementPanelAction.ts

@@ -0,0 +1,17 @@
+import { YTNode } from '../../helpers.js';
+import type { RawNode } from '../../index.js';
+import Parser from '../../index.js';
+import Transcript from '../Transcript.js';
+
+export default class UpdateEngagementPanelAction extends YTNode {
+  static type = 'UpdateEngagementPanelAction';
+
+  target_id: string;
+  content: Transcript | null;
+
+  constructor(data: RawNode) {
+    super();
+    this.target_id = data.targetId;
+    this.content = Parser.parseItem(data.content, Transcript);
+  }
+}

src/parser/classes/menus/MenuPopup.ts

@@ -0,0 +1,17 @@
+import type { ObservedArray} from '../../helpers.js';
+import { YTNode } from '../../helpers.js';
+import type { RawNode } from '../../index.js';
+import Parser from '../../index.js';
+import MenuNavigationItem from './MenuNavigationItem.js';
+import MenuServiceItem from './MenuServiceItem.js';
+
+export default class MenuPopup extends YTNode {
+  static type = 'MenuPopup';
+
+  items: ObservedArray<MenuNavigationItem | MenuServiceItem>;
+
+  constructor(data: RawNode) {
+    super();
+    this.items = Parser.parseArray(data.items, [ MenuNavigationItem, MenuServiceItem ]);
+  }
+}

src/parser/nodes.ts

@@ -7,6 +7,7 @@ export { default as AccountItemSectionHeader } from './classes/AccountItemSectio
 export { default as AccountSectionList } from './classes/AccountSectionList.js';
 export { default as AppendContinuationItemsAction } from './classes/actions/AppendContinuationItemsAction.js';
 export { default as OpenPopupAction } from './classes/actions/OpenPopupAction.js';
+export { default as UpdateEngagementPanelAction } from './classes/actions/UpdateEngagementPanelAction.js';
 export { default as Alert } from './classes/Alert.js';
 export { default as AlertWithButton } from './classes/AlertWithButton.js';
 export { default as AnalyticsMainAppKeyMetrics } from './classes/analytics/AnalyticsMainAppKeyMetrics.js';
@@ -102,6 +103,7 @@ export { default as ExpandableTab } from './classes/ExpandableTab.js';
 export { default as ExpandableVideoDescriptionBody } from './classes/ExpandableVideoDescriptionBody.js';
 export { default as ExpandedShelfContents } from './classes/ExpandedShelfContents.js';
 export { default as Factoid } from './classes/Factoid.js';
+export { default as FancyDismissibleDialog } from './classes/FancyDismissibleDialog.js';
 export { default as FeedFilterChipBar } from './classes/FeedFilterChipBar.js';
 export { default as FeedTabbedHeader } from './classes/FeedTabbedHeader.js';
 export { default as GameCard } from './classes/GameCard.js';
@@ -191,6 +193,7 @@ export { default as MacroMarkersList } from './classes/MacroMarkersList.js';
 export { default as MacroMarkersListItem } from './classes/MacroMarkersListItem.js';
 export { default as Menu } from './classes/menus/Menu.js';
 export { default as MenuNavigationItem } from './classes/menus/MenuNavigationItem.js';
+export { default as MenuPopup } from './classes/menus/MenuPopup.js';
 export { default as MenuServiceItem } from './classes/menus/MenuServiceItem.js';
 export { default as MenuServiceItemDownload } from './classes/menus/MenuServiceItemDownload.js';
 export { default as MultiPageMenu } from './classes/menus/MultiPageMenu.js';
@@ -274,6 +277,9 @@ export { default as PlaylistVideoThumbnail } from './classes/PlaylistVideoThumbn
 export { default as Poll } from './classes/Poll.js';
 export { default as Post } from './classes/Post.js';
 export { default as PostMultiImage } from './classes/PostMultiImage.js';
+export { default as ProductList } from './classes/ProductList.js';
+export { default as ProductListHeader } from './classes/ProductListHeader.js';
+export { default as ProductListItem } from './classes/ProductListItem.js';
 export { default as ProfileColumn } from './classes/ProfileColumn.js';
 export { default as ProfileColumnStats } from './classes/ProfileColumnStats.js';
 export { default as ProfileColumnStatsEntry } from './classes/ProfileColumnStatsEntry.js';
@@ -349,10 +355,17 @@ export { default as ToggleButton } from './classes/ToggleButton.js';
 export { default as ToggleMenuServiceItem } from './classes/ToggleMenuServiceItem.js';
 export { default as Tooltip } from './classes/Tooltip.js';
 export { default as TopicChannelDetails } from './classes/TopicChannelDetails.js';
+export { default as Transcript } from './classes/Transcript.js';
+export { default as TranscriptFooter } from './classes/TranscriptFooter.js';
+export { default as TranscriptSearchBox } from './classes/TranscriptSearchBox.js';
+export { default as TranscriptSearchPanel } from './classes/TranscriptSearchPanel.js';
+export { default as TranscriptSegment } from './classes/TranscriptSegment.js';
+export { default as TranscriptSegmentList } from './classes/TranscriptSegmentList.js';
 export { default as TwoColumnBrowseResults } from './classes/TwoColumnBrowseResults.js';
 export { default as TwoColumnSearchResults } from './classes/TwoColumnSearchResults.js';
 export { default as TwoColumnWatchNextResults } from './classes/TwoColumnWatchNextResults.js';
 export { default as UniversalWatchCard } from './classes/UniversalWatchCard.js';
+export { default as UploadTimeFactoid } from './classes/UploadTimeFactoid.js';
 export { default as UpsellDialog } from './classes/UpsellDialog.js';
 export { default as VerticalList } from './classes/VerticalList.js';
 export { default as VerticalWatchCardList } from './classes/VerticalWatchCardList.js';
@@ -361,10 +374,12 @@ export { default as VideoCard } from './classes/VideoCard.js';
 export { default as VideoDescriptionHeader } from './classes/VideoDescriptionHeader.js';
 export { default as VideoDescriptionInfocardsSection } from './classes/VideoDescriptionInfocardsSection.js';
 export { default as VideoDescriptionMusicSection } from './classes/VideoDescriptionMusicSection.js';
+export { default as VideoDescriptionTranscriptSection } from './classes/VideoDescriptionTranscriptSection.js';
 export { default as VideoInfoCardContent } from './classes/VideoInfoCardContent.js';
 export { default as VideoOwner } from './classes/VideoOwner.js';
 export { default as VideoPrimaryInfo } from './classes/VideoPrimaryInfo.js';
 export { default as VideoSecondaryInfo } from './classes/VideoSecondaryInfo.js';
+export { default as ViewCountFactoid } from './classes/ViewCountFactoid.js';
 export { default as WatchCardCompactVideo } from './classes/WatchCardCompactVideo.js';
 export { default as WatchCardHeroVideo } from './classes/WatchCardHeroVideo.js';
 export { default as WatchCardRichHeader } from './classes/WatchCardRichHeader.js';

src/parser/parser.ts

@@ -7,6 +7,7 @@ import PlayerLiveStoryboardSpec from './classes/PlayerLiveStoryboardSpec.js';
 import PlayerStoryboardSpec from './classes/PlayerStoryboardSpec.js';
 import Alert from './classes/Alert.js';
 import AlertWithButton from './classes/AlertWithButton.js';
+import EngagementPanelSectionList from './classes/EngagementPanelSectionList.js';
 
 import type { IParsedResponse, IRawResponse, RawData, RawNode } from './types/index.js';
 
@@ -21,7 +22,13 @@ import { Memo, observe, SuperParsedResult } from './helpers.js';
 import * as YTNodes from './nodes.js';
 import type { KeyInfo } from './generator.js';
 import { camelToSnake, generateRuntimeClass, generateTypescriptClass } from './generator.js';
-import { Continuation, ItemSectionContinuation, SectionListContinuation, LiveChatContinuation, MusicPlaylistShelfContinuation, MusicShelfContinuation, GridContinuation, PlaylistPanelContinuation, NavigateAction, ShowMiniplayerCommand, ReloadContinuationItemsCommand } from './continuations.js';
+
+import {
+  Continuation, ItemSectionContinuation, SectionListContinuation,
+  LiveChatContinuation, MusicPlaylistShelfContinuation, MusicShelfContinuation,
+  GridContinuation, PlaylistPanelContinuation, NavigateAction, ShowMiniplayerCommand,
+  ReloadContinuationItemsCommand
+} from './continuations.js';
 
 export type ParserError = {
   classname: string,
@@ -289,6 +296,14 @@ export function parseResponse<T extends IParsedResponse = IParsedResponse>(data:
   }
   _clearMemo();
 
+  _createMemo();
+  const items = parse(data.items);
+  if (items) {
+    parsed_data.items = items;
+    parsed_data.items_memo = _getMemo();
+  }
+  _clearMemo();
+
   applyMutations(contents_memo, data.frameworkUpdates?.entityBatchUpdate?.mutations);
 
   const continuation = data.continuation ? parseC(data.continuation) : null;
@@ -404,20 +419,10 @@ export function parseResponse<T extends IParsedResponse = IParsedResponse>(data:
     parsed_data.cards = cards;
   }
 
-  const engagement_panels = data.engagementPanels?.map((e) => {
-    const item = parseItem(e, YTNodes.EngagementPanelSectionList) as YTNodes.EngagementPanelSectionList;
-    return item;
-  });
-  if (engagement_panels) {
+  const engagement_panels = parseArray(data.engagementPanels, EngagementPanelSectionList);
+  if (engagement_panels.length) {
     parsed_data.engagement_panels = engagement_panels;
   }
-  _createMemo();
-  const items = parse(data.items);
-  if (items) {
-    parsed_data.items = items;
-    parsed_data.items_memo = _getMemo();
-  }
-  _clearMemo();
 
   return parsed_data;
 }
@@ -429,7 +434,7 @@ export function parseResponse<T extends IParsedResponse = IParsedResponse>(data:
  */
 export function parseItem<T extends YTNode, K extends YTNodeConstructor<T>[]>(data: RawNode | undefined, validTypes: K): InstanceType<K[number]> | null;
 export function parseItem<T extends YTNode>(data: RawNode | undefined, validTypes: YTNodeConstructor<T>): T | null;
-export function parseItem(data?: RawNode) : YTNode;
+export function parseItem(data?: RawNode): YTNode;
 export function parseItem(data?: RawNode, validTypes?: YTNodeConstructor | YTNodeConstructor[]) {
   if (!data) return null;
 

src/parser/types/ParsedResponse.ts

@@ -20,6 +20,7 @@ import type NavigationEndpoint from '../classes/NavigationEndpoint.js';
 import type PlayerAnnotationsExpanded from '../classes/PlayerAnnotationsExpanded.js';
 import type EngagementPanelSectionList from '../classes/EngagementPanelSectionList.js';
 import type { AppendContinuationItemsAction } from '../nodes.js';
+
 export interface IParsedResponse {
   actions?: SuperParsedResult<YTNode>;
   actions_memo?: Memo;
@@ -63,7 +64,7 @@ export interface IParsedResponse {
   storyboards?: PlayerStoryboardSpec | PlayerLiveStoryboardSpec;
   endscreen?: Endscreen;
   cards?: CardCollection;
-  engagement_panels?: EngagementPanelSectionList[];
+  engagement_panels?: ObservedArray<EngagementPanelSectionList>;
   items?: SuperParsedResult<YTNode>;
 }
 
@@ -106,7 +107,7 @@ export interface INextResponse {
   on_response_received_endpoints?: ObservedArray<ReloadContinuationItemsCommand | AppendContinuationItemsAction>;
   on_response_received_endpoints_memo?: Memo;
   player_overlays?: SuperParsedResult<YTNode>;
-  engagement_panels?: EngagementPanelSectionList[];
+  engagement_panels?: ObservedArray<EngagementPanelSectionList>;
 }
 
 export interface IBrowseResponse {
@@ -145,6 +146,11 @@ export interface IResolveURLResponse {
   endpoint: NavigationEndpoint;
 }
 
+export interface IGetTranscriptResponse {
+  actions: SuperParsedResult<YTNode>;
+  actions_memo: Memo;
+}
+
 export interface IGetNotificationsMenuResponse {
   actions: SuperParsedResult<YTNode>;
   actions_memo: Memo;