feat(Channel): Support new about popup (#537)

* feat(Channel): Support new about popup

* chore: Minor cleanup

* fix(concatMemos): Merge duplicate nodes instead of overwriting

* fix(Feed): `has_continuation` and `getContinuation()` avoid header continuations

* chore(Channel): Remove unused import

---------

Co-authored-by: LuanRT <luan.lrt4@gmail.com>

src/parser/classes/AboutChannel.ts

@@ -0,0 +1,18 @@
+import { YTNode } from '../helpers.js';
+import { Parser, type RawNode } from '../index.js';
+import AboutChannelView from './AboutChannelView.js';
+import Button from './Button.js';
+
+export default class AboutChannel extends YTNode {
+  static type = 'AboutChannel';
+
+  metadata: AboutChannelView | null;
+  share_channel: Button | null;
+
+  constructor(data: RawNode) {
+    super();
+
+    this.metadata = Parser.parseItem(data.metadata, AboutChannelView);
+    this.share_channel = Parser.parseItem(data.shareChannel, Button);
+  }
+}

src/parser/classes/AboutChannelView.ts

@@ -0,0 +1,87 @@
+import type { ObservedArray } from '../helpers.js';
+import { YTNode } from '../helpers.js';
+import { Parser, type RawNode } from '../index.js';
+import ChannelExternalLinkView from './ChannelExternalLinkView.js';
+import NavigationEndpoint from './NavigationEndpoint.js';
+import Text from './misc/Text.js';
+
+export default class AboutChannelView extends YTNode {
+  static type = 'AboutChannelView';
+
+  description?: string;
+  description_label?: Text;
+  country?: string;
+  custom_links_label?: Text;
+  subscriber_count?: string;
+  view_count?: string;
+  joined_date?: Text;
+  canonical_channel_url?: string;
+  channel_id?: string;
+  additional_info_label?: Text;
+  custom_url_on_tap?: NavigationEndpoint;
+  video_count?: string;
+  sign_in_for_business_email?: Text;
+  links: ObservedArray<ChannelExternalLinkView>;
+
+  constructor(data: RawNode) {
+    super();
+
+    if (Reflect.has(data, 'description')) {
+      this.description = data.description;
+    }
+
+    if (Reflect.has(data, 'descriptionLabel')) {
+      this.description_label = Text.fromAttributed(data.descriptionLabel);
+    }
+
+    if (Reflect.has(data, 'country')) {
+      this.country = data.country;
+    }
+
+    if (Reflect.has(data, 'customLinksLabel')) {
+      this.custom_links_label = Text.fromAttributed(data.customLinksLabel);
+    }
+
+    if (Reflect.has(data, 'subscriberCountText')) {
+      this.subscriber_count = data.subscriberCountText;
+    }
+
+    if (Reflect.has(data, 'viewCountText')) {
+      this.view_count = data.viewCountText;
+    }
+
+    if (Reflect.has(data, 'joinedDateText')) {
+      this.joined_date = Text.fromAttributed(data.joinedDateText);
+    }
+
+    if (Reflect.has(data, 'canonicalChannelUrl')) {
+      this.canonical_channel_url = data.canonicalChannelUrl;
+    }
+
+    if (Reflect.has(data, 'channelId')) {
+      this.channel_id = data.channelId;
+    }
+
+    if (Reflect.has(data, 'additionalInfoLabel')) {
+      this.additional_info_label = Text.fromAttributed(data.additionalInfoLabel);
+    }
+
+    if (Reflect.has(data, 'customUrlOnTap')) {
+      this.custom_url_on_tap = new NavigationEndpoint(data.customUrlOnTap);
+    }
+
+    if (Reflect.has(data, 'videoCountText')) {
+      this.video_count = data.videoCountText;
+    }
+
+    if (Reflect.has(data, 'signInForBusinessEmail')) {
+      this.sign_in_for_business_email = Text.fromAttributed(data.signInForBusinessEmail);
+    }
+
+    if (Reflect.has(data, 'links')) {
+      this.links = Parser.parseArray(data.links, ChannelExternalLinkView);
+    } else {
+      this.links = [] as unknown as ObservedArray<ChannelExternalLinkView>;
+    }
+  }
+}

src/parser/classes/C4TabbedHeader.ts

@@ -3,6 +3,7 @@ import Parser, { type RawNode } from '../index.js';
 import Button from './Button.js';
 import ChannelHeaderLinks from './ChannelHeaderLinks.js';
 import ChannelHeaderLinksView from './ChannelHeaderLinksView.js';
+import ChannelTagline from './ChannelTagline.js';
 import SubscribeButton from './SubscribeButton.js';
 import Author from './misc/Author.js';
 import Text from './misc/Text.js';
@@ -22,6 +23,7 @@ export default class C4TabbedHeader extends YTNode {
   header_links?: ChannelHeaderLinks | ChannelHeaderLinksView | null;
   channel_handle?: Text;
   channel_id?: string;
+  tagline?: ChannelTagline | null;
 
   constructor(data: RawNode) {
     super();
@@ -69,5 +71,9 @@ export default class C4TabbedHeader extends YTNode {
     if (Reflect.has(data, 'channelId')) {
       this.channel_id = data.channelId;
     }
+
+    if (Reflect.has(data, 'tagline')) {
+      this.tagline = Parser.parseItem(data.tagline, ChannelTagline);
+    }
   }
 }

src/parser/classes/ChannelExternalLinkView.ts

@@ -0,0 +1,20 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+import Text from './misc/Text.js';
+import Thumbnail from './misc/Thumbnail.js';
+
+export default class ChannelExternalLinkView extends YTNode {
+  static type = 'ChannelExternalLinkView';
+
+  title: Text;
+  link: Text;
+  favicon: Thumbnail[];
+
+  constructor(data: RawNode) {
+    super();
+
+    this.title = Text.fromAttributed(data.title);
+    this.link = Text.fromAttributed(data.link);
+    this.favicon = data.favicon.sources.map((x: any) => new Thumbnail(x)).sort((a: Thumbnail, b: Thumbnail) => b.width - a.width);
+  }
+}

src/parser/classes/ChannelTagline.ts

@@ -0,0 +1,44 @@
+import { YTNode } from '../helpers.js';
+import { Parser, type RawNode } from '../index.js';
+import NavigationEndpoint from './NavigationEndpoint.js';
+import EngagementPanelSectionList from './EngagementPanelSectionList.js';
+
+export default class ChannelTagline extends YTNode {
+  static type = 'ChannelTagline';
+
+  content: string;
+  max_lines: number;
+  more_endpoint: {
+    show_engagement_panel_endpoint: {
+      engagement_panel: EngagementPanelSectionList | null,
+      engagement_panel_popup_type: string;
+      identifier: {
+        surface: string,
+        tag: string
+      }
+    }
+  } | NavigationEndpoint;
+  more_icon_type: string;
+  more_label: string;
+  target_id: string;
+
+  constructor(data: RawNode) {
+    super();
+
+    this.content = data.content;
+    this.max_lines = data.maxLines;
+    this.more_endpoint = data.moreEndpoint.showEngagementPanelEndpoint ? {
+      show_engagement_panel_endpoint: {
+        engagement_panel: Parser.parseItem(data.moreEndpoint.showEngagementPanelEndpoint.engagementPanel, EngagementPanelSectionList),
+        engagement_panel_popup_type: data.moreEndpoint.showEngagementPanelEndpoint.engagementPanelPresentationConfigs.engagementPanelPopupPresentationConfig.popupType,
+        identifier: {
+          surface: data.moreEndpoint.showEngagementPanelEndpoint.identifier.surface,
+          tag: data.moreEndpoint.showEngagementPanelEndpoint.identifier.tag
+        }
+      }
+    } : new NavigationEndpoint(data.moreEndpoint);
+    this.more_icon_type = data.moreIcon.iconType;
+    this.more_label = data.moreLabel;
+    this.target_id = data.targetId;
+  }
+}

src/parser/classes/EngagementPanelSectionList.ts

@@ -16,6 +16,10 @@ export default class EngagementPanelSectionList extends YTNode {
   content: VideoAttributeView | SectionList | ContinuationItem | ClipSection | StructuredDescriptionContent | MacroMarkersList | ProductList | null;
   target_id?: string;
   panel_identifier?: string;
+  identifier?: {
+    surface: string,
+    tag: string
+  };
   visibility?: string;
 
   constructor(data: RawNode) {
@@ -23,6 +27,10 @@ export default class EngagementPanelSectionList extends YTNode {
     this.header = Parser.parseItem(data.header, EngagementPanelTitleHeader);
     this.content = Parser.parseItem(data.content, [ VideoAttributeView, SectionList, ContinuationItem, ClipSection, StructuredDescriptionContent, MacroMarkersList, ProductList ]);
     this.panel_identifier = data.panelIdentifier;
+    this.identifier = data.identifier ? {
+      surface: data.identifier.surface,
+      tag: data.identifier.tag
+    } : undefined;
     this.target_id = data.targetId;
     this.visibility = data.visibility;
   }

src/parser/classes/misc/Text.ts

@@ -56,6 +56,10 @@ export default class Text {
     const content = data.content;
     const command_runs = data.commandRuns;
 
+    // Haven't found an actually useful one yet, but they look like this:
+    // [ { startIndex: 0, length: 19 } ] (for a string that is 19 characters long)
+    // Const style_runs = data.styleRuns;
+
     let last_end_index = 0;
 
     if (command_runs) {