Profile redesign: Timeline filters (#37626)

app/javascript/mastodon/selectors/timelines.ts

@@ -0,0 +1,51 @@
+import type { Map as ImmutableMap } from 'immutable';
+import { List as ImmutableList } from 'immutable';
+
+import type { TimelineParams } from '../actions/timelines_typed';
+import { timelineKey } from '../actions/timelines_typed';
+import { createAppSelector } from '../store';
+
+interface TimelineShape {
+  unread: number;
+  online: boolean;
+  top: boolean;
+  isLoading: boolean;
+  hasMore: boolean;
+  pendingItems: ImmutableList<string>;
+  items: ImmutableList<string>;
+}
+
+type TimelinesState = ImmutableMap<string, ImmutableMap<string, unknown>>;
+
+const emptyList = ImmutableList<string>();
+
+export const selectTimelineByKey = createAppSelector(
+  [(_, key: string) => key, (state) => state.timelines as TimelinesState],
+  (key, timelines) => toTypedTimeline(timelines.get(key)),
+);
+
+export const selectTimelineByParams = createAppSelector(
+  [
+    (_, params: TimelineParams) => timelineKey(params),
+    (state) => state.timelines as TimelinesState,
+  ],
+  (key, timelines) => toTypedTimeline(timelines.get(key)),
+);
+
+export function toTypedTimeline(timeline?: ImmutableMap<string, unknown>) {
+  if (!timeline) {
+    return null;
+  }
+  return {
+    unread: timeline.get('unread', 0) as number,
+    online: !!timeline.get('online', false),
+    top: !!timeline.get('top', false),
+    isLoading: !!timeline.get('isLoading', true),
+    hasMore: !!timeline.get('hasMore', false),
+    pendingItems: timeline.get(
+      'pendingItems',
+      emptyList,
+    ) as ImmutableList<string>,
+    items: timeline.get('items', emptyList) as ImmutableList<string>,
+  } as TimelineShape;
+}