feat: add support for hashtag feeds (#312)

* feat: add hashtag params proto

* feat: add support for hashtags

* chore: add test

* docs: update API ref

* fix(tests): remove unneeded `#` from param

* fix: do not throw when missing the header

src/parser/classes/HashtagHeader.ts

@@ -0,0 +1,18 @@
+import { YTNode } from '../helpers.js';
+import Text from './misc/Text.js';
+import type { RawNode } from '../index.js';
+
+class HashtagHeader extends YTNode {
+  static type = 'HashtagHeader';
+
+  hashtag: Text;
+  hashtag_info: Text;
+
+  constructor(data: RawNode) {
+    super();
+    this.hashtag = new Text(data.hashtag);
+    this.hashtag_info = new Text(data.hashtagInfoText);
+  }
+}
+
+export default HashtagHeader;

src/parser/map.ts

@@ -98,6 +98,7 @@ import { default as GridChannel } from './classes/GridChannel.js';
 import { default as GridHeader } from './classes/GridHeader.js';
 import { default as GridPlaylist } from './classes/GridPlaylist.js';
 import { default as GridVideo } from './classes/GridVideo.js';
+import { default as HashtagHeader } from './classes/HashtagHeader.js';
 import { default as Heatmap } from './classes/Heatmap.js';
 import { default as HeatMarker } from './classes/HeatMarker.js';
 import { default as HighlightsCarousel } from './classes/HighlightsCarousel.js';
@@ -428,6 +429,7 @@ export const YTNodes = {
   GridHeader,
   GridPlaylist,
   GridVideo,
+  HashtagHeader,
   Heatmap,
   HeatMarker,
   HighlightsCarousel,

src/parser/youtube/HashtagFeed.ts

@@ -0,0 +1,42 @@
+import FilterableFeed from '../../core/FilterableFeed.js';
+import { InnertubeError } from '../../utils/Utils.js';
+import HashtagHeader from '../classes/HashtagHeader.js';
+import RichGrid from '../classes/RichGrid.js';
+import Tab from '../classes/Tab.js';
+
+import type Actions from '../../core/Actions.js';
+import type { ApiResponse } from '../../core/Actions.js';
+import type ChipCloudChip from '../classes/ChipCloudChip.js';
+import type { IBrowseResponse } from '../index.js';
+
+export default class HashtagFeed extends FilterableFeed<IBrowseResponse> {
+  header?: HashtagHeader;
+  contents: RichGrid;
+
+  constructor(actions: Actions, response: IBrowseResponse | ApiResponse) {
+    super(actions, response);
+
+    if (!this.page.contents_memo)
+      throw new InnertubeError('Unexpected response', this.page);
+
+    const tab = this.page.contents_memo.getType(Tab).first();
+
+    if (!tab.content)
+      throw new InnertubeError('Content tab has no content', tab);
+
+    if (this.page.header) {
+      this.header = this.page.header.item().as(HashtagHeader);
+    }
+
+    this.contents = tab.content.as(RichGrid);
+  }
+
+  /**
+   * Applies given filter and returns a new {@link HashtagFeed} object. Use {@link HashtagFeed.filters} to get available filters.
+   * @param filter - Filter to apply.
+   */
+  async applyFilter(filter: string | ChipCloudChip): Promise<HashtagFeed> {
+    const response = await super.getFilteredFeed(filter);
+    return new HashtagFeed(this.actions, response.page);
+  }
+}