DP18: add getMemberName helper and dedup name-fallback sites

Add a pure `getMemberName(room, userId): string` helper in utils/room.ts
(= getMemberDisplayName ?? getMxIdLocalPart ?? userId) and replace the
inline `getMemberDisplayName(room, id) ?? getMxIdLocalPart(id) ?? id`
fallback across the codebase. No behavior change.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/components/CallEmbedProvider.tsx

@@ -59,7 +59,7 @@ import { useTheme, ThemeKind } from '../hooks/useTheme';
 import { useReducedMotion } from '../hooks/useReducedMotion';
 import { useSetting } from '../state/hooks/settings';
 import { settingsAtom } from '../state/settings';
-import { getStateEvent, getStateEvents, getMemberDisplayName } from '../utils/room';
+import { getStateEvent, getStateEvents, getMemberName } from '../utils/room';
 import { StateEvent } from '../../types/matrix/room';
 import { getPowersLevelFromMatrixEvent } from '../hooks/usePowerLevels';
 import { getRoomCreatorsForRoomId } from '../hooks/useRoomCreators';
@@ -161,9 +161,7 @@ function IncomingCall({ dm, info, onIgnore, onAnswer, onReject }: IncomingCallPr
           <Dialog style={{ maxWidth: toRem(324) }}>
             <Box style={{ padding: config.space.S400 }} direction="Column" gap="700">
               <Text size="T200" align="Center">
-                {getMemberDisplayName(info.room, info.sender) ??
-                  getMxIdLocalPart(info.sender) ??
-                  info.sender}
+                {getMemberName(info.room, info.sender)}
               </Text>
               <Box direction="Column" gap="500" alignItems="Center">
                 <Box shrink="No">
@@ -316,8 +314,7 @@ function IncomingCallBanner({ dm, info, onIgnore, onAnswer, onReject }: Incoming
     return () => clearTimeout(id);
   }, [info.senderTs, info.lifetime, onIgnore]);
 
-  const callerName =
-    getMemberDisplayName(info.room, info.sender) ?? getMxIdLocalPart(info.sender) ?? info.sender;
+  const callerName = getMemberName(info.room, info.sender);
 
   return (
     <Box
@@ -453,8 +450,7 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
           decliner !== mx.getSafeUserId() &&
           callEmbed?.roomId === room.roomId
         ) {
-          const declinerName =
-            getMemberDisplayName(room, decliner) ?? getMxIdLocalPart(decliner) ?? decliner;
+          const declinerName = getMemberName(room, decliner);
           setToast({
             id: `rtc-decline-${event.getId() ?? decliner}`,
             displayName: declinerName,

src/app/components/editor/autocomplete/UserMentionAutocomplete.tsx

@@ -16,7 +16,7 @@ import { onTabPress } from '../../../utils/keyboard';
 import { createMentionElement, moveCursor, replaceWithElement } from '../utils';
 import { useKeyDown } from '../../../hooks/useKeyDown';
 import { getMxIdLocalPart, getMxIdServer, isUserId } from '../../../utils/matrix';
-import { getMemberDisplayName, getMemberSearchStr } from '../../../utils/room';
+import { getMemberName, getMemberSearchStr } from '../../../utils/room';
 import { UserAvatar } from '../../user-avatar';
 import { useMediaAuthentication } from '../../../hooks/useMediaAuthentication';
 import { Membership } from '../../../../types/matrix/room';
@@ -140,8 +140,7 @@ export function UserMentionAutocomplete({
     });
   });
 
-  const getName = (member: RoomMember) =>
-    getMemberDisplayName(room, member.userId) ?? getMxIdLocalPart(member.userId) ?? member.userId;
+  const getName = (member: RoomMember) => getMemberName(room, member.userId);
 
   return (
     <AutocompleteMenu headerContent={<Text size="L400">Mentions</Text>} requestClose={requestClose}>

src/app/components/member-tile/MemberTile.tsx

@@ -1,13 +1,12 @@
 import React, { ReactNode } from 'react';
 import { as, Avatar, Box, Icon, Icons, Text } from 'folds';
 import { MatrixClient, Room, RoomMember } from 'matrix-js-sdk';
-import { getMemberDisplayName } from '../../utils/room';
+import { getMemberName } from '../../utils/room';
 import { getMxIdLocalPart } from '../../utils/matrix';
 import { UserAvatar } from '../user-avatar';
 import * as css from './style.css';
 
-const getName = (room: Room, member: RoomMember) =>
-  getMemberDisplayName(room, member.userId) ?? getMxIdLocalPart(member.userId) ?? member.userId;
+const getName = (room: Room, member: RoomMember) => getMemberName(room, member.userId);
 
 type MemberTileProps = {
   mx: MatrixClient;

src/app/features/call-status/LiveChip.tsx

@@ -20,8 +20,8 @@ import FocusTrap from 'focus-trap-react';
 import { Room } from 'matrix-js-sdk';
 import * as css from './styles.css';
 import { stopPropagation } from '../../utils/keyboard';
-import { getMemberAvatarMxc, getMemberDisplayName } from '../../utils/room';
-import { getMxIdLocalPart, mxcUrlToHttp } from '../../utils/matrix';
+import { getMemberAvatarMxc, getMemberName } from '../../utils/room';
+import { mxcUrlToHttp } from '../../utils/matrix';
 import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { useMediaAuthentication } from '../../hooks/useMediaAuthentication';
 import { UserAvatar } from '../../components/user-avatar';
@@ -77,8 +77,7 @@ export function LiveChip({ count, room, members }: LiveChipProps) {
                     {members.map((callMember) => {
                       const userId = callMember.sender;
                       if (!userId) return null;
-                      const name =
-                        getMemberDisplayName(room, userId) ?? getMxIdLocalPart(userId) ?? userId;
+                      const name = getMemberName(room, userId);
                       const avatarMxc = getMemberAvatarMxc(room, userId);
                       const avatarUrl = avatarMxc
                         ? (mxcUrlToHttp(mx, avatarMxc, useAuthentication, 96, 96) ?? undefined)

src/app/features/call-status/MemberGlance.tsx

@@ -4,8 +4,8 @@ import React, { useState } from 'react';
 import FocusTrap from 'focus-trap-react';
 import { Room } from 'matrix-js-sdk';
 import { UserAvatar } from '../../components/user-avatar';
-import { getMemberAvatarMxc, getMemberDisplayName } from '../../utils/room';
-import { getMxIdLocalPart, mxcUrlToHttp } from '../../utils/matrix';
+import { getMemberAvatarMxc, getMemberName } from '../../utils/room';
+import { mxcUrlToHttp } from '../../utils/matrix';
 import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { useMediaAuthentication } from '../../hooks/useMediaAuthentication';
 import { StackedAvatar } from '../../components/stacked-avatar';
@@ -128,7 +128,7 @@ export function MemberGlance({ room, members, speakers, callEmbed, max = 6 }: Me
         {visibleMembers.map((callMember) => {
           const { userId } = callMember;
           if (!userId) return null;
-          const name = getMemberDisplayName(room, userId) ?? getMxIdLocalPart(userId) ?? userId;
+          const name = getMemberName(room, userId);
           const avatarMxc = getMemberAvatarMxc(room, userId);
           const avatarUrl = avatarMxc
             ? (mxcUrlToHttp(mx, avatarMxc, useAuthentication, 96, 96) ?? undefined)

src/app/features/call-status/MemberSpeaking.tsx

@@ -1,17 +1,14 @@
 import { Room } from 'matrix-js-sdk';
 import React from 'react';
 import { Box, Icon, Icons, Text } from 'folds';
-import { getMemberDisplayName } from '../../utils/room';
-import { getMxIdLocalPart } from '../../utils/matrix';
+import { getMemberName } from '../../utils/room';
 
 type MemberSpeakingProps = {
   room: Room;
   speakers: Set<string>;
 };
 export function MemberSpeaking({ room, speakers }: MemberSpeakingProps) {
-  const speakingNames = Array.from(speakers).map(
-    (userId) => getMemberDisplayName(room, userId) ?? getMxIdLocalPart(userId) ?? userId,
-  );
+  const speakingNames = Array.from(speakers).map((userId) => getMemberName(room, userId));
   return (
     <Box alignItems="Center" gap="100">
       <Icon size="100" src={Icons.Mic} filled />

src/app/features/call/CallMemberCard.tsx

@@ -5,9 +5,9 @@ import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { useMediaAuthentication } from '../../hooks/useMediaAuthentication';
 import { useOpenUserRoomProfile } from '../../state/hooks/userRoomProfile';
 import { SequenceCard } from '../../components/sequence-card';
-import { getMemberAvatarMxc, getMemberDisplayName } from '../../utils/room';
+import { getMemberAvatarMxc, getMemberName } from '../../utils/room';
 import { useRoom } from '../../hooks/useRoom';
-import { getMxIdLocalPart, mxcUrlToHttp } from '../../utils/matrix';
+import { mxcUrlToHttp } from '../../utils/matrix';
 import { UserAvatar } from '../../components/user-avatar';
 import { AvatarDecoration } from '../../components/avatar-decoration/AvatarDecoration';
 import { getMouseEventCords } from '../../utils/dom';
@@ -26,7 +26,7 @@ export function CallMemberCard({ member }: CallMemberCardProps) {
   const { userId } = member;
   if (!userId) return null;
 
-  const name = getMemberDisplayName(room, userId) ?? getMxIdLocalPart(userId) ?? userId;
+  const name = getMemberName(room, userId);
   const avatarMxc = getMemberAvatarMxc(room, userId);
   const avatarUrl = avatarMxc
     ? (mxcUrlToHttp(mx, avatarMxc, useAuthentication, 96, 96) ?? undefined)

src/app/features/message-search/SearchResultGroup.tsx

@@ -12,7 +12,7 @@ import {
   makeMentionCustomProps,
   renderMatrixMention,
 } from '../../plugins/react-custom-html-parser';
-import { getMxIdLocalPart, mxcUrlToHttp } from '../../utils/matrix';
+import { mxcUrlToHttp } from '../../utils/matrix';
 import { useMatrixEventRenderer } from '../../hooks/useMatrixEventRenderer';
 import { GetContentCallback, MessageEvent, StateEvent } from '../../../types/matrix/room';
 import {
@@ -31,7 +31,7 @@ import { Image } from '../../components/media';
 import { ImageViewer } from '../../components/image-viewer';
 import * as customHtmlCss from '../../styles/CustomHtml.css';
 import { RoomAvatar, RoomIcon } from '../../components/room-avatar';
-import { getMemberAvatarMxc, getMemberDisplayName, getRoomAvatarUrl } from '../../utils/room';
+import { getMemberAvatarMxc, getMemberName, getRoomAvatarUrl } from '../../utils/room';
 import { ResultItem } from './useMessageSearch';
 import { SequenceCard } from '../../components/sequence-card';
 import { UserAvatar } from '../../components/user-avatar';
@@ -220,10 +220,7 @@ export function SearchResultGroup({
         {items.map((item) => {
           const { event } = item;
 
-          const displayName =
-            getMemberDisplayName(room, event.sender) ??
-            getMxIdLocalPart(event.sender) ??
-            event.sender;
+          const displayName = getMemberName(room, event.sender);
           const senderAvatarMxc = getMemberAvatarMxc(room, event.sender);
 
           const relation = event.content['m.relates_to'];

src/app/features/room-settings/RoomInsights.tsx

@@ -6,8 +6,8 @@ import { SequenceCard } from '../../components/sequence-card';
 import { useRoom } from '../../hooks/useRoom';
 import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { useMediaAuthentication } from '../../hooks/useMediaAuthentication';
-import { getMemberAvatarMxc, getMemberDisplayName } from '../../utils/room';
-import { getMxIdLocalPart, mxcUrlToHttp } from '../../utils/matrix';
+import { getMemberAvatarMxc, getMemberName } from '../../utils/room';
+import { mxcUrlToHttp } from '../../utils/matrix';
 import { UserAvatar } from '../../components/user-avatar';
 
 // ── Helpers ───────────────────────────────────────────────────────────────────
@@ -297,8 +297,7 @@ export function RoomInsights({ requestClose }: RoomInsightsProps) {
                   <SectionHeader label="Most Active Members" />
                   <Box direction="Column" gap="200">
                     {stats.top5.map(([userId, count], index) => {
-                      const displayName =
-                        getMemberDisplayName(room, userId) ?? getMxIdLocalPart(userId) ?? userId;
+                      const displayName = getMemberName(room, userId);
                       const avatarMxc = getMemberAvatarMxc(room, userId);
                       const avatarUrl = avatarMxc
                         ? (mxcUrlToHttp(mx, avatarMxc, useAuthentication, 32, 32, 'crop') ??

src/app/features/room/MembersDrawer.tsx

@@ -42,7 +42,7 @@ import {
 } from '../../hooks/useAsyncSearch';
 import { useDebounce } from '../../hooks/useDebounce';
 import { TypingIndicator } from '../../components/typing-indicator';
-import { getMemberDisplayName, getMemberSearchStr } from '../../utils/room';
+import { getMemberName, getMemberSearchStr } from '../../utils/room';
 import { getMxIdLocalPart } from '../../utils/matrix';
 import { useSetSetting, useSetting } from '../../state/hooks/settings';
 import { settingsAtom } from '../../state/settings';
@@ -134,8 +134,7 @@ function MemberItem({
   typing,
   showEncryption,
 }: MemberItemProps) {
-  const name =
-    getMemberDisplayName(room, member.userId) ?? getMxIdLocalPart(member.userId) ?? member.userId;
+  const name = getMemberName(room, member.userId);
   const avatarMxcUrl = member.getMxcAvatarUrl();
   const avatarUrl = avatarMxcUrl
     ? mx.mxcUrlToHttp(avatarMxcUrl, 100, 100, 'crop', undefined, false, useAuthentication)
@@ -418,10 +417,7 @@ export function MembersDrawer({ room, members }: MembersDrawerProps) {
                   Pending Requests
                 </Text>
                 {knockMembers.map((knockMember) => {
-                  const knockName =
-                    getMemberDisplayName(room, knockMember.userId) ??
-                    getMxIdLocalPart(knockMember.userId) ??
-                    knockMember.userId;
+                  const knockName = getMemberName(room, knockMember.userId);
                   const knockAvatarMxc = knockMember.getMxcAvatarUrl();
                   const knockAvatarUrl = knockAvatarMxc
                     ? mx.mxcUrlToHttp(

src/app/features/room/RoomInput.tsx

@@ -65,7 +65,6 @@ import {
   TUploadContent,
   encryptFile,
   getImageInfo,
-  getMxIdLocalPart,
   mxcUrlToHttp,
   tryDeleteMxcContent,
 } from '../../utils/matrix';
@@ -111,7 +110,7 @@ import {
   getImageMsgContent,
   getVideoMsgContent,
 } from './msgContent';
-import { getMemberDisplayName, getMentionContent, trimReplyFromBody } from '../../utils/room';
+import { getMemberName, getMentionContent, trimReplyFromBody } from '../../utils/room';
 import { CommandAutocomplete } from './CommandAutocomplete';
 import { Command, SHRUG, TABLEFLIP, UNFLIP, useCommands } from '../../hooks/useCommands';
 import { mobileOrTablet } from '../../utils/user-agent';
@@ -993,11 +992,7 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
                       userColor={replyUsernameColor}
                       username={
                         <Text size="T300" truncate>
-                          <b>
-                            {getMemberDisplayName(room, replyDraft.userId) ??
-                              getMxIdLocalPart(replyDraft.userId) ??
-                              replyDraft.userId}
-                          </b>
+                          <b>{getMemberName(room, replyDraft.userId)}</b>
                         </Text>
                       }
                     >

src/app/features/room/RoomTimeline.tsx

@@ -81,6 +81,7 @@ import {
   getEventReactions,
   getLatestEditableEvt,
   getMemberDisplayName,
+  getMemberName,
   getReactionContent,
   isMembershipChanged,
   reactionOrEditEvent,
@@ -1007,7 +1008,7 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
         console.warn('Button should have "data-user-id" attribute!');
         return;
       }
-      const name = getMemberDisplayName(room, userId) ?? getMxIdLocalPart(userId) ?? userId;
+      const name = getMemberName(room, userId);
       editor.insertNode(
         createMentionElement(
           userId,
@@ -1106,8 +1107,7 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
           editedEvent?.getContent()['m.new_content'] ?? mEvent.getContent()) as GetContentCallback;
 
         const senderId = mEvent.getSender() ?? '';
-        const senderDisplayName =
-          getMemberDisplayName(room, senderId) ?? getMxIdLocalPart(senderId) ?? senderId;
+        const senderDisplayName = getMemberName(room, senderId);
 
         return (
           <Message
@@ -1290,8 +1290,7 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
                     mEvent.getContent()) as GetContentCallback;
 
                   const senderId = mEvent.getSender() ?? '';
-                  const senderDisplayName =
-                    getMemberDisplayName(room, senderId) ?? getMxIdLocalPart(senderId) ?? senderId;
+                  const senderDisplayName = getMemberName(room, senderId);
                   return (
                     <RenderMessageContent
                       displayName={senderDisplayName}

src/app/features/room/RoomViewFollowing.tsx

@@ -15,8 +15,7 @@ import { Room } from 'matrix-js-sdk';
 import classNames from 'classnames';
 import FocusTrap from 'focus-trap-react';
 
-import { getMemberDisplayName } from '../../utils/room';
-import { getMxIdLocalPart } from '../../utils/matrix';
+import { getMemberName } from '../../utils/room';
 import * as css from './RoomViewFollowing.css';
 import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { useRoomLatestRenderedEvent } from '../../hooks/useRoomLatestRenderedEvent';
@@ -39,10 +38,7 @@ export const RoomViewFollowing = as<'div', RoomViewFollowingProps>(
     const latestEventReaders = useRoomEventReaders(room, latestEvent?.getId());
     const names = latestEventReaders
       .filter((readerId) => readerId !== mx.getUserId())
-      .map(
-        (readerId) =>
-          getMemberDisplayName(room, readerId) ?? getMxIdLocalPart(readerId) ?? readerId,
-      );
+      .map((readerId) => getMemberName(room, readerId));
 
     const eventId = latestEvent?.getId();
 

src/app/features/room/message/Message.tsx

@@ -53,9 +53,9 @@ import {
   canEditEvent,
   getEventEdits,
   getMemberAvatarMxc,
-  getMemberDisplayName,
+  getMemberName,
 } from '../../../utils/room';
-import { getMxIdLocalPart, mxcUrlToHttp } from '../../../utils/matrix';
+import { mxcUrlToHttp } from '../../../utils/matrix';
 import { messageAriaLabel } from '../../../utils/a11y';
 import { MessageLayout, MessageSpacing } from '../../../state/settings';
 import { useMatrixClient } from '../../../hooks/useMatrixClient';
@@ -809,8 +809,7 @@ export const Message = React.memo(
       const [remindOpen, setRemindOpen] = useState(false);
       const { addBookmark, removeBookmark, isBookmarked } = useBookmarks();
 
-      const senderDisplayName =
-        getMemberDisplayName(room, senderId) ?? getMxIdLocalPart(senderId) ?? senderId;
+      const senderDisplayName = getMemberName(room, senderId);
       const senderAvatarMxc = getMemberAvatarMxc(room, senderId);
 
       const tagColor = memberPowerTag?.color

src/app/features/room/message/MessageEditor.tsx

@@ -53,11 +53,10 @@ import { AsyncStatus, useAsyncCallback } from '../../../hooks/useAsyncCallback';
 import { useMatrixClient } from '../../../hooks/useMatrixClient';
 import {
   getEditedEvent,
-  getMemberDisplayName,
+  getMemberName,
   getMentionContent,
   trimReplyFromFormattedBody,
 } from '../../../utils/room';
-import { getMxIdLocalPart } from '../../../utils/matrix';
 import { mobileOrTablet } from '../../../utils/user-agent';
 import { useComposingCheck } from '../../../hooks/useComposingCheck';
 
@@ -75,9 +74,7 @@ export const MessageEditor = as<'div', MessageEditorProps>(
     // Accessible name for the edit textbox so screen readers announce which
     // message is being edited (a11y, P3-4).
     const editSenderId = mEvent.getSender();
-    const editSenderName = editSenderId
-      ? (getMemberDisplayName(room, editSenderId) ?? getMxIdLocalPart(editSenderId) ?? editSenderId)
-      : '';
+    const editSenderName = editSenderId ? getMemberName(room, editSenderId) : '';
     const [enterForNewline] = useSetting(settingsAtom, 'enterForNewline');
     const [globalToolbar] = useSetting(settingsAtom, 'editorToolbar');
     const [isMarkdown] = useSetting(settingsAtom, 'isMarkdown');

src/app/features/room/reaction-viewer/ReactionViewer.tsx

@@ -16,7 +16,7 @@ import {
 } from 'folds';
 import { MatrixEvent, Room, RoomMember } from 'matrix-js-sdk';
 import { Relations } from 'matrix-js-sdk/lib/models/relations';
-import { getMemberDisplayName } from '../../../utils/room';
+import { getMemberName } from '../../../utils/room';
 import { eventWithShortcode, getMxIdLocalPart } from '../../../utils/matrix';
 import * as css from './ReactionViewer.css';
 import { useMatrixClient } from '../../../hooks/useMatrixClient';
@@ -67,8 +67,7 @@ export const ReactionViewer = as<'div', ReactionViewerProps>(
       }
     };
 
-    const getName = (member: RoomMember) =>
-      getMemberDisplayName(room, member.userId) ?? getMxIdLocalPart(member.userId) ?? member.userId;
+    const getName = (member: RoomMember) => getMemberName(room, member.userId);
 
     const getReactionsForKey = (key: string): MatrixEvent[] => {
       const reactSet = reactions.find(([k]) => k === key)?.[1];

src/app/features/room/room-pin-menu/RoomPinMenu.tsx

@@ -40,12 +40,12 @@ import {
   UsernameBold,
 } from '../../../components/message';
 import { UserAvatar } from '../../../components/user-avatar';
-import { getMxIdLocalPart, mxcUrlToHttp } from '../../../utils/matrix';
+import { mxcUrlToHttp } from '../../../utils/matrix';
 import { useMatrixClient } from '../../../hooks/useMatrixClient';
 import {
   getEditedEvent,
   getMemberAvatarMxc,
-  getMemberDisplayName,
+  getMemberName,
   getStateEvent,
 } from '../../../utils/room';
 import { GetContentCallback, MessageEvent, StateEvent } from '../../../../types/matrix/room';
@@ -175,7 +175,7 @@ function PinnedMessage({
     );
 
   const sender = pinnedEvent.getSender()!;
-  const displayName = getMemberDisplayName(room, sender) ?? getMxIdLocalPart(sender) ?? sender;
+  const displayName = getMemberName(room, sender);
   const senderAvatarMxc = getMemberAvatarMxc(room, sender);
   const getContent = (() => pinnedEvent.getContent()) as GetContentCallback;
 

src/app/features/room/thread/ThreadTimeline.tsx

@@ -32,7 +32,7 @@ import { useAtomValue, useSetAtom } from 'jotai';
 import { Badge, Box, Chip, Icon, Icons, Line, Scroll, Spinner, Text, color, config } from 'folds';
 import classNames from 'classnames';
 import { Opts as LinkifyOpts } from 'linkifyjs';
-import { eventWithShortcode, factoryEventSentBy, getMxIdLocalPart } from '../../../utils/matrix';
+import { eventWithShortcode, factoryEventSentBy } from '../../../utils/matrix';
 import { useMatrixClient } from '../../../hooks/useMatrixClient';
 import { useVirtualPaginator, ItemRange } from '../../../hooks/useVirtualPaginator';
 import { useAlive } from '../../../hooks/useAlive';
@@ -58,7 +58,7 @@ import {
   decryptAllTimelineEvent,
   getEditedEvent,
   getEventReactions,
-  getMemberDisplayName,
+  getMemberName,
   getReactionContent,
   reactionOrEditEvent,
 } from '../../../utils/room';
@@ -503,7 +503,7 @@ export function ThreadTimeline({ room, thread, editor }: ThreadTimelineProps) {
       evt.preventDefault();
       const userId = evt.currentTarget.getAttribute('data-user-id');
       if (!userId) return;
-      const name = getMemberDisplayName(room, userId) ?? getMxIdLocalPart(userId) ?? userId;
+      const name = getMemberName(room, userId);
       editor.insertNode(
         createMentionElement(
           userId,
@@ -651,8 +651,7 @@ export function ThreadTimeline({ room, thread, editor }: ThreadTimelineProps) {
         const getContent = (() =>
           editedEvent?.getContent()['m.new_content'] ?? mEvent.getContent()) as GetContentCallback;
         const senderId = mEvent.getSender() ?? '';
-        const senderDisplayName =
-          getMemberDisplayName(room, senderId) ?? getMxIdLocalPart(senderId) ?? senderId;
+        const senderDisplayName = getMemberName(room, senderId);
         return (
           <RenderMessageContent
             displayName={senderDisplayName}

src/app/pages/client/ClientNonUIFeatures.tsx

@@ -27,13 +27,13 @@ import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { getDirectRoomPath, getHomeRoomPath, getInboxInvitesPath } from '../pathUtils';
 import { mDirectAtom } from '../../state/mDirectList';
 import {
-  getMemberDisplayName,
+  getMemberName,
   getNotificationType,
   getUnreadInfo,
   isNotificationEvent,
 } from '../../utils/room';
 import { NotificationType } from '../../../types/matrix/room';
-import { getMxIdLocalPart, mxcUrlToHttp } from '../../utils/matrix';
+import { mxcUrlToHttp } from '../../utils/matrix';
 import { useSelectedRoom } from '../../hooks/router/useSelectedRoom';
 import { useInboxNotificationsSelected } from '../../hooks/router/useInbox';
 import { useMediaAuthentication } from '../../hooks/useMediaAuthentication';
@@ -501,7 +501,7 @@ function MessageNotifications() {
           roomAvatar: avatarMxc
             ? (mxcUrlToHttp(mx, avatarMxc, useAuthentication, 96, 96, 'crop') ?? undefined)
             : undefined,
-          username: getMemberDisplayName(room, sender) ?? getMxIdLocalPart(sender) ?? sender,
+          username: getMemberName(room, sender),
           roomId: room.roomId,
           eventId,
           body: (mEvent.getContent().body as string | undefined) ?? '',

src/app/pages/client/inbox/Invites.tsx

@@ -37,7 +37,7 @@ import {
   bannedInRooms,
   getCommonRooms,
   getDirectRoomAvatarUrl,
-  getMemberDisplayName,
+  getMemberName,
   getRoomAvatarUrl,
   getStateEvent,
   isDirectInvite,
@@ -48,7 +48,6 @@ import { RoomAvatar } from '../../../components/room-avatar';
 import {
   addRoomIdToMDirect,
   declineInvite,
-  getMxIdLocalPart,
   guessDmRoomUserId,
   rateLimitedActions,
 } from '../../../utils/matrix';
@@ -107,9 +106,7 @@ const makeInviteData = (mx: MatrixClient, room: Room, useAuthentication: boolean
   const content = memberEvent?.getContent();
   const senderId = memberEvent?.getSender();
 
-  const senderName = senderId
-    ? (getMemberDisplayName(room, senderId) ?? getMxIdLocalPart(senderId) ?? senderId)
-    : undefined;
+  const senderName = senderId ? getMemberName(room, senderId) : undefined;
   const inviteTs = memberEvent?.getTs();
   const reason =
     content && 'reason' in content && typeof content.reason === 'string'

src/app/pages/client/inbox/Notifications.tsx

@@ -28,7 +28,7 @@ import { Opts as LinkifyOpts } from 'linkifyjs';
 import { useAtomValue } from 'jotai';
 import { Page, PageContent, PageContentCenter, PageHeader } from '../../../components/page';
 import { useMatrixClient } from '../../../hooks/useMatrixClient';
-import { getMxIdLocalPart, mxcUrlToHttp } from '../../../utils/matrix';
+import { mxcUrlToHttp } from '../../../utils/matrix';
 import { InboxNotificationsPathSearchParams } from '../../paths';
 import { AsyncStatus, useAsyncCallback } from '../../../hooks/useAsyncCallback';
 import { SequenceCard } from '../../../components/sequence-card';
@@ -36,7 +36,7 @@ import { RoomAvatar, RoomIcon } from '../../../components/room-avatar';
 import {
   getEditedEvent,
   getMemberAvatarMxc,
-  getMemberDisplayName,
+  getMemberName,
   getRoomAvatarUrl,
 } from '../../../utils/room';
 import { ScrollTopContainer } from '../../../components/scroll-top-container';
@@ -448,10 +448,7 @@ function RoomNotificationsGroupComp({
         {notifications.map((notification) => {
           const { event } = notification;
 
-          const displayName =
-            getMemberDisplayName(room, event.sender) ??
-            getMxIdLocalPart(event.sender) ??
-            event.sender;
+          const displayName = getMemberName(room, event.sender);
           const senderAvatarMxc = getMemberAvatarMxc(room, event.sender);
           const getContent = (() => event.content) as GetContentCallback;
 

src/app/utils/room.ts

@@ -30,6 +30,7 @@ import {
   UnreadInfo,
 } from '../../types/matrix/room';
 import { getMutedThreads, ThreadNotificationsContent } from './threadNotifications';
+import { getMxIdLocalPart } from './matrix';
 
 export const getStateEvent = (
   room: Room,
@@ -405,6 +406,9 @@ export const getMemberDisplayName = (room: Room, userId: string): string | undef
   return name;
 };
 
+export const getMemberName = (room: Room, userId: string): string =>
+  getMemberDisplayName(room, userId) ?? getMxIdLocalPart(userId) ?? userId;
+
 export const getMemberSearchStr = (
   member: RoomMember,
   query: string,