feat: Add "Followers you know" widget to user profiles (#34652)

app/javascript/mastodon/features/account_timeline/components/account_header.tsx

@@ -59,6 +59,7 @@ import {
 import { getAccountHidden } from 'mastodon/selectors/accounts';
 import { useAppSelector, useAppDispatch } from 'mastodon/store';
 
+import { FamiliarFollowers } from './familiar_followers';
 import { MemorialNote } from './memorial_note';
 import { MovedNote } from './moved_note';
 
@@ -1022,6 +1023,7 @@ export const AccountHeader: React.FC<{
                   />
                 </NavLink>
               </div>
+              <FamiliarFollowers accountId={accountId} />
             </div>
           )}
         </div>

app/javascript/mastodon/features/account_timeline/components/familiar_followers.tsx

@@ -0,0 +1,84 @@
+import { useEffect } from 'react';
+
+import { FormattedMessage } from 'react-intl';
+
+import { Link } from 'react-router-dom';
+
+import { fetchAccountsFamiliarFollowers } from '@/mastodon/actions/accounts_familiar_followers';
+import { AvatarGroup } from '@/mastodon/components/avatar_group';
+import type { Account } from '@/mastodon/models/account';
+import { getAccountFamiliarFollowers } from '@/mastodon/selectors/accounts';
+import { useAppDispatch, useAppSelector } from '@/mastodon/store';
+
+const AccountLink: React.FC<{ account?: Account }> = ({ account }) => (
+  <Link to={`/@${account?.username}`} data-hover-card-account={account?.id}>
+    {account?.display_name}
+  </Link>
+);
+
+const FamiliarFollowersReadout: React.FC<{ familiarFollowers: Account[] }> = ({
+  familiarFollowers,
+}) => {
+  const messageData = {
+    name1: <AccountLink account={familiarFollowers.at(0)} />,
+    name2: <AccountLink account={familiarFollowers.at(1)} />,
+    othersCount: familiarFollowers.length - 2,
+  };
+
+  if (familiarFollowers.length === 1) {
+    return (
+      <FormattedMessage
+        id='account.familiar_followers_one'
+        defaultMessage='Followed by {name1}'
+        values={messageData}
+      />
+    );
+  } else if (familiarFollowers.length === 2) {
+    return (
+      <FormattedMessage
+        id='account.familiar_followers_two'
+        defaultMessage='Followed by {name1} and {name2}'
+        values={messageData}
+      />
+    );
+  } else {
+    return (
+      <FormattedMessage
+        id='account.familiar_followers_many'
+        defaultMessage='Followed by {name1}, {name2}, and {othersCount, plural, one {# other} other {# others}}'
+        values={messageData}
+      />
+    );
+  }
+};
+
+export const FamiliarFollowers: React.FC<{ accountId: string }> = ({
+  accountId,
+}) => {
+  const dispatch = useAppDispatch();
+  const familiarFollowers = useAppSelector((state) =>
+    getAccountFamiliarFollowers(state, accountId),
+  );
+
+  const hasNoData = familiarFollowers === null;
+
+  useEffect(() => {
+    if (hasNoData) {
+      void dispatch(fetchAccountsFamiliarFollowers({ id: accountId }));
+    }
+  }, [dispatch, accountId, hasNoData]);
+
+  if (hasNoData || familiarFollowers.length === 0) {
+    return null;
+  }
+
+  return (
+    <div className='account__header__familiar-followers'>
+      <AvatarGroup
+        compact
+        accountIds={familiarFollowers.slice(0, 3).map((account) => account.id)}
+      />
+      <FamiliarFollowersReadout familiarFollowers={familiarFollowers} />
+    </div>
+  );
+};

app/javascript/mastodon/features/notifications_v2/components/avatar_group.tsx

@@ -1,31 +0,0 @@
-import { Link } from 'react-router-dom';
-
-import { Avatar } from 'mastodon/components/avatar';
-import { NOTIFICATIONS_GROUP_MAX_AVATARS } from 'mastodon/models/notification_group';
-import { useAppSelector } from 'mastodon/store';
-
-const AvatarWrapper: React.FC<{ accountId: string }> = ({ accountId }) => {
-  const account = useAppSelector((state) => state.accounts.get(accountId));
-
-  if (!account) return null;
-
-  return (
-    <Link
-      to={`/@${account.acct}`}
-      title={`@${account.acct}`}
-      data-hover-card-account={account.id}
-    >
-      <Avatar account={account} size={28} />
-    </Link>
-  );
-};
-
-export const AvatarGroup: React.FC<{ accountIds: string[] }> = ({
-  accountIds,
-}) => (
-  <div className='notification-group__avatar-group'>
-    {accountIds.slice(0, NOTIFICATIONS_GROUP_MAX_AVATARS).map((accountId) => (
-      <AvatarWrapper key={accountId} accountId={accountId} />
-    ))}
-  </div>
-);

app/javascript/mastodon/features/notifications_v2/components/notification_group_with_status.tsx

@@ -7,12 +7,13 @@ import { HotKeys } from 'react-hotkeys';
 
 import { replyComposeById } from 'mastodon/actions/compose';
 import { navigateToStatus } from 'mastodon/actions/statuses';
+import { AvatarGroup } from 'mastodon/components/avatar_group';
 import type { IconProp } from 'mastodon/components/icon';
 import { Icon } from 'mastodon/components/icon';
 import { RelativeTimestamp } from 'mastodon/components/relative_timestamp';
+import { NOTIFICATIONS_GROUP_MAX_AVATARS } from 'mastodon/models/notification_group';
 import { useAppSelector, useAppDispatch } from 'mastodon/store';
 
-import { AvatarGroup } from './avatar_group';
 import { DisplayedName } from './displayed_name';
 import { EmbeddedStatus } from './embedded_status';
 
@@ -98,7 +99,12 @@ export const NotificationGroupWithStatus: React.FC<{
         <div className='notification-group__main'>
           <div className='notification-group__main__header'>
             <div className='notification-group__main__header__wrapper'>
-              <AvatarGroup accountIds={accountIds} />
+              <AvatarGroup
+                accountIds={accountIds.slice(
+                  0,
+                  NOTIFICATIONS_GROUP_MAX_AVATARS,
+                )}
+              />
 
               {actions && (
                 <div className='notification-group__actions'>{actions}</div>