chore: upgrade React 18→19 and fix breaking type changes

- react 18.2.0 to 19.2.6
- react-dom 18.2.0 to 19.2.6
- @types/react 18.2.39 to 19.2.15
- @types/react-dom 18.2.17 to 19.2.3

React 19 breaking changes fixed:
- useRef<T>(null) now returns RefObject<T | null>; cast to
  RefObject<T> at 16 component call sites (safe, runtime unchanged)
- useRef<T>() without arg no longer valid; add | undefined>(undefined)
  in useDebounce, useFileDrop, useThrottle, useVirtualPaginator hooks,
  RoomInput, RoomTimeline, and ClientNonUIFeatures
- useReducer<typeof reducer> 1-arg form removed; drop explicit type arg
  in useForceUpdate (inferred from reducer function)
- global JSX namespace removed; import type { JSX } from react in
  react-custom-html-parser.tsx

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package-lock.json

@@ -57,11 +57,11 @@
         "millify": "6.1.0",
         "pdfjs-dist": "5.7.284",
         "prismjs": "1.30.0",
-        "react": "18.2.0",
+        "react": "19.2.6",
         "react-aria": "3.48.0",
         "react-blurhash": "0.3.0",
         "react-colorful": "5.7.0",
-        "react-dom": "18.2.0",
+        "react-dom": "19.2.6",
         "react-error-boundary": "6.1.1",
         "react-google-recaptcha": "3.1.0",
         "react-i18next": "17.0.8",
@@ -88,8 +88,8 @@
         "@types/is-hotkey": "0.1.10",
         "@types/node": "25.9.1",
         "@types/prismjs": "1.26.6",
-        "@types/react": "18.2.39",
+        "@types/react": "19.2.15",
-        "@types/react-dom": "18.2.17",
+        "@types/react-dom": "19.2.3",
         "@types/react-google-recaptcha": "2.1.9",
         "@types/sanitize-html": "2.16.1",
         "@types/ua-parser-js": "0.7.39",
@@ -5365,30 +5365,24 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/@types/prop-types": {
-      "version": "15.7.14",
-      "resolved": "https://registry.npmjs.org/@types/prop-types/-/prop-types-15.7.14.tgz",
-      "integrity": "sha512-gNMvNH49DJ7OJYv+KAKn0Xp45p8PLl6zo2YnvDIbTd4J6MER2BmWN49TG7n9LvkyihINxeKW8+3bfS2yDC9dzQ==",
-      "dev": true
-    },
     "node_modules/@types/react": {
-      "version": "18.2.39",
+      "version": "19.2.15",
-      "resolved": "https://registry.npmjs.org/@types/react/-/react-18.2.39.tgz",
+      "resolved": "https://registry.npmjs.org/@types/react/-/react-19.2.15.tgz",
-      "integrity": "sha512-Oiw+ppED6IremMInLV4HXGbfbG6GyziY3kqAwJYOR0PNbkYDmLWQA3a95EhdSmamsvbkJN96ZNN+YD+fGjzSBA==",
+      "integrity": "sha512-eRwcGNHve+E8qtEQSSRl6urh+rFop4v8gm6O8rGv25CodbvFdLjA1vVQ1KkiFE0w0UPOnb8tDiFKL5lp0rtY5Q==",
       "dev": true,
+      "license": "MIT",
       "dependencies": {
-        "@types/prop-types": "*",
+        "csstype": "^3.2.2"
-        "@types/scheduler": "*",
-        "csstype": "^3.0.2"
       }
     },
     "node_modules/@types/react-dom": {
-      "version": "18.2.17",
+      "version": "19.2.3",
-      "resolved": "https://registry.npmjs.org/@types/react-dom/-/react-dom-18.2.17.tgz",
+      "resolved": "https://registry.npmjs.org/@types/react-dom/-/react-dom-19.2.3.tgz",
-      "integrity": "sha512-rvrT/M7Df5eykWFxn6MYt5Pem/Dbyc1N8Y0S9Mrkw2WFCRiqUgw9P7ul2NpwsXCSM1DVdENzdG9J5SreqfAIWg==",
+      "integrity": "sha512-jp2L/eY6fn+KgVVQAOqYItbF0VY/YApe5Mz2F0aykSO8gx31bYCZyvSeYxCHKvzHG5eZjc+zyaS5BrBWya2+kQ==",
       "dev": true,
-      "dependencies": {
+      "license": "MIT",
-        "@types/react": "*"
+      "peerDependencies": {
+        "@types/react": "^19.2.0"
       }
     },
     "node_modules/@types/react-google-recaptcha": {
@@ -5418,12 +5412,6 @@
         "htmlparser2": "^10.1"
       }
     },
-    "node_modules/@types/scheduler": {
-      "version": "0.23.0",
-      "resolved": "https://registry.npmjs.org/@types/scheduler/-/scheduler-0.23.0.tgz",
-      "integrity": "sha512-YIoDCTH3Af6XM5VuwGG/QL/CJqga1Zm3NkU3HZ4ZHK2fRMPYP1VczsTUqtsf43PH/iJNVlPHAo2oWX7BSdB2Hw==",
-      "dev": true
-    },
     "node_modules/@types/trusted-types": {
       "version": "2.0.7",
       "resolved": "https://registry.npmjs.org/@types/trusted-types/-/trusted-types-2.0.7.tgz",
@@ -15744,12 +15732,10 @@
       }
     },
     "node_modules/react": {
-      "version": "18.2.0",
+      "version": "19.2.6",
-      "resolved": "https://registry.npmjs.org/react/-/react-18.2.0.tgz",
+      "resolved": "https://registry.npmjs.org/react/-/react-19.2.6.tgz",
-      "integrity": "sha512-/3IjMdb2L9QbBdWiW5e3P2/npwMBaU9mHCSCUzNln0ZCYbcfTsGbTJrU/kGemdH2IWmB2ioZ+zkxtmq6g09fGQ==",
+      "integrity": "sha512-sfWGGfavi0xr8Pg0sVsyHMAOziVYKgPLNrS7ig+ivMNb3wbCBw3KxtflsGBAwD3gYQlE/AEZsTLgToRrSCjb0Q==",
-      "dependencies": {
+      "license": "MIT",
-        "loose-envify": "^1.1.0"
-      },
       "engines": {
         "node": ">=0.10.0"
       }
@@ -15808,15 +15794,15 @@
       }
     },
     "node_modules/react-dom": {
-      "version": "18.2.0",
+      "version": "19.2.6",
-      "resolved": "https://registry.npmjs.org/react-dom/-/react-dom-18.2.0.tgz",
+      "resolved": "https://registry.npmjs.org/react-dom/-/react-dom-19.2.6.tgz",
-      "integrity": "sha512-6IMTriUmvsjHUjNtEDudZfuDQUoWXVxKHhlEGSk81n4YFS+r/Kl99wXiwlVXtPBtJenozv2P+hxDsw9eA7Xo6g==",
+      "integrity": "sha512-0prMI+hvBbPjsWnxDLxlCGyM8PN6UuWjEUCYmZhO67xIV9Xasa/r/vDnq+Xyq4Lo27g8QSbO5YzARu0D1Sps3g==",
+      "license": "MIT",
       "dependencies": {
-        "loose-envify": "^1.1.0",
+        "scheduler": "^0.27.0"
-        "scheduler": "^0.23.0"
       },
       "peerDependencies": {
-        "react": "^18.2.0"
+        "react": "^19.2.6"
       }
     },
     "node_modules/react-error-boundary": {
@@ -16528,12 +16514,10 @@
       }
     },
     "node_modules/scheduler": {
-      "version": "0.23.2",
+      "version": "0.27.0",
-      "resolved": "https://registry.npmjs.org/scheduler/-/scheduler-0.23.2.tgz",
+      "resolved": "https://registry.npmjs.org/scheduler/-/scheduler-0.27.0.tgz",
-      "integrity": "sha512-UOShsPwz7NrMUqhR6t0hWjFduvOzbtv7toDH1/hIrfRNIDBnnBWd0CwJTGvTpngVlmwGCdP9/Zl/tVrDqcuYzQ==",
+      "integrity": "sha512-eNv+WrVbKu1f3vbYJT/xtiF5syA5HPIMtf9IgY/nKg0sWqzAUEvqY/xm7OcZc/qafLx/iO9FgOmeSAp4v5ti/Q==",
-      "dependencies": {
+      "license": "MIT"
-        "loose-envify": "^1.1.0"
-      }
     },
     "node_modules/screenfull": {
       "version": "5.2.0",

package.json

@@ -110,11 +110,11 @@
     "millify": "6.1.0",
     "pdfjs-dist": "5.7.284",
     "prismjs": "1.30.0",
-    "react": "18.2.0",
+    "react": "19.2.6",
     "react-aria": "3.48.0",
     "react-blurhash": "0.3.0",
     "react-colorful": "5.7.0",
-    "react-dom": "18.2.0",
+    "react-dom": "19.2.6",
     "react-error-boundary": "6.1.1",
     "react-google-recaptcha": "3.1.0",
     "react-i18next": "17.0.8",
@@ -141,8 +141,8 @@
     "@types/is-hotkey": "0.1.10",
     "@types/node": "25.9.1",
     "@types/prismjs": "1.26.6",
-    "@types/react": "18.2.39",
+    "@types/react": "19.2.15",
-    "@types/react-dom": "18.2.17",
+    "@types/react-dom": "19.2.3",
     "@types/react-google-recaptcha": "2.1.9",
     "@types/sanitize-html": "2.16.1",
     "@types/ua-parser-js": "0.7.39",

src/app/components/CallEmbedProvider.tsx

@@ -399,7 +399,7 @@ type CallEmbedProviderProps = {
 };
 export function CallEmbedProvider({ children }: CallEmbedProviderProps) {
   const callEmbed = useAtomValue(callEmbedAtom);
-  const callEmbedRef = useRef<HTMLDivElement>(null);
+  const callEmbedRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
   const joined = useCallJoined(callEmbed);
 
   const selectedRoom = useSelectedRoom();

src/app/components/ConfirmPasswordMatch.tsx

@@ -12,8 +12,8 @@ type ConfirmPasswordMatchProps = {
 };
 export function ConfirmPasswordMatch({ initialValue, children }: ConfirmPasswordMatchProps) {
   const [match, setMatch] = useState(initialValue);
-  const passRef = useRef<HTMLInputElement>(null);
+  const passRef = useRef<HTMLInputElement>(null) as React.RefObject<HTMLInputElement>;
-  const confPassRef = useRef<HTMLInputElement>(null);
+  const confPassRef = useRef<HTMLInputElement>(null) as React.RefObject<HTMLInputElement>;
 
   const doMatch = useDebounce(
     useCallback(() => {

src/app/components/emoji-board/EmojiBoard.tsx

@@ -421,8 +421,8 @@ export function EmojiBoard({
     { wait: 200 },
   );
 
-  const contentScrollRef = useRef<HTMLDivElement>(null);
+  const contentScrollRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
-  const virtualBaseRef = useRef<HTMLDivElement>(null);
+  const virtualBaseRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
   const virtualizer = useVirtualizer({
     count: groups.length,
     getScrollElement: () => contentScrollRef.current,

src/app/features/call/CallView.tsx

@@ -152,7 +152,7 @@ function CallJoined({ joined, containerRef }: CallJoinedProps) {
 
 export function CallView() {
   const room = useRoom();
-  const callContainerRef = useRef<HTMLDivElement>(null);
+  const callContainerRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
   useCallEmbedPlacementSync(callContainerRef);
 
   const callEmbed = useCallEmbed();

src/app/features/common-settings/members/Members.tsx

@@ -95,9 +95,9 @@ export function Members({ requestClose }: MembersProps) {
   const memberSort = useMemberSort(sortFilterIndex, useMemberSortMenu());
   const memberPowerSort = useMemberPowerSort(creators, getPowerLevel);
 
-  const scrollRef = useRef<HTMLDivElement>(null);
+  const scrollRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
-  const searchInputRef = useRef<HTMLInputElement>(null);
+  const searchInputRef = useRef<HTMLInputElement>(null) as React.RefObject<HTMLInputElement>;
-  const scrollTopAnchorRef = useRef<HTMLDivElement>(null);
+  const scrollTopAnchorRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
 
   const sortedMembers = useMemo(
     () =>

src/app/features/lobby/Lobby.tsx

@@ -159,8 +159,8 @@ export function Lobby() {
   const lex = useMemo(() => new ASCIILexicalTable(' '.charCodeAt(0), '~'.charCodeAt(0), 6), []);
   const members = useRoomMembers(mx, space.roomId);
 
-  const scrollRef = useRef<HTMLDivElement>(null);
+  const scrollRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
-  const heroSectionRef = useRef<HTMLDivElement>(null);
+  const heroSectionRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
   const [heroSectionHeight, setHeroSectionHeight] = useState<number>();
   const [spaceRooms, setSpaceRooms] = useAtom(spaceRoomsAtom);
   const [isDrawer] = useSetting(settingsAtom, 'isPeopleDrawer');

src/app/features/lobby/RoomItem.tsx

@@ -315,8 +315,8 @@ export const RoomItemCard = as<'div', RoomItemCardProps>(
     const useAuthentication = useMediaAuthentication();
     const { roomId, content } = item;
     const room = getRoom(roomId);
-    const targetRef = useRef<HTMLDivElement>(null);
+    const targetRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
-    const targetHandleRef = useRef<HTMLDivElement>(null);
+    const targetHandleRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
     useDraggableItem(item, targetRef, onDragging, targetHandleRef);
 
     const joined = room?.getMyMembership() === Membership.Join;

src/app/features/lobby/SpaceItem.tsx

@@ -429,7 +429,7 @@ export const SpaceItemCard = as<'div', SpaceItemCardProps>(
     const useAuthentication = useMediaAuthentication();
     const { roomId, content } = item;
     const space = getRoom(roomId);
-    const targetRef = useRef<HTMLDivElement>(null);
+    const targetRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
     useDraggableItem(item, targetRef, onDragging);
 
     return (

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

@@ -60,8 +60,8 @@ export function MessageSearch({
   const [hour24Clock] = useSetting(settingsAtom, 'hour24Clock');
   const [dateFormatString] = useSetting(settingsAtom, 'dateFormatString');
 
-  const searchInputRef = useRef<HTMLInputElement>(null);
+  const searchInputRef = useRef<HTMLInputElement>(null) as React.RefObject<HTMLInputElement>;
-  const scrollTopAnchorRef = useRef<HTMLDivElement>(null);
+  const scrollTopAnchorRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
   const [searchParams, setSearchParams] = useSearchParams();
   const searchPathSearchParams = useSearchPathSearchParams(searchParams);
   const { navigateRoom } = useRoomNavigate();

src/app/features/room/MembersDrawer.tsx

@@ -180,9 +180,9 @@ type MembersDrawerProps = {
 export function MembersDrawer({ room, members }: MembersDrawerProps) {
   const mx = useMatrixClient();
   const useAuthentication = useMediaAuthentication();
-  const scrollRef = useRef<HTMLDivElement>(null);
+  const scrollRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
-  const searchInputRef = useRef<HTMLInputElement>(null);
+  const searchInputRef = useRef<HTMLInputElement>(null) as React.RefObject<HTMLInputElement>;
-  const scrollTopAnchorRef = useRef<HTMLDivElement>(null);
+  const scrollTopAnchorRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
   const powerLevels = usePowerLevelsContext();
   const creators = useRoomCreators(room);
   const getPowerTag = useGetMemberPowerTag(room, creators, powerLevels);

src/app/features/room/RoomInput.tsx

@@ -176,7 +176,7 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
       roomUploadAtomFamily,
       selectedFiles.map((f) => f.file),
     );
-    const uploadBoardHandlers = useRef<UploadBoardImperativeHandlers>();
+    const uploadBoardHandlers = useRef<UploadBoardImperativeHandlers | undefined>(undefined);
 
     const imagePackRooms: Room[] = useImagePackRooms(roomId, roomToParents);
 

src/app/features/room/RoomTimeline.tsx

@@ -494,7 +494,7 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
   const imagePackRooms: Room[] = useImagePackRooms(room.roomId, roomToParents);
 
   const [unreadInfo, setUnreadInfo] = useState(() => getRoomUnreadInfo(room, true));
-  const readUptoEventIdRef = useRef<string>();
+  const readUptoEventIdRef = useRef<string | undefined>(undefined);
   if (unreadInfo) {
     readUptoEventIdRef.current = unreadInfo.readUptoEventId;
   }

src/app/features/room/RoomView.tsx

@@ -57,8 +57,8 @@ const shouldFocusMessageField = (evt: KeyboardEvent): boolean => {
 };
 
 export function RoomView({ eventId }: { eventId?: string }) {
-  const roomInputRef = useRef<HTMLDivElement>(null);
+  const roomInputRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
-  const roomViewRef = useRef<HTMLDivElement>(null);
+  const roomViewRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
   const [chatBackground] = useSetting(settingsAtom, 'chatBackground');
   const [lotusTerminal] = useSetting(settingsAtom, 'lotusTerminal');
   const theme = useTheme();

src/app/hooks/useDebounce.ts

@@ -10,7 +10,7 @@ export function useDebounce<T extends unknown[]>(
   callback: DebounceCallback<T>,
   options?: DebounceOptions,
 ): DebounceCallback<T> {
-  const timeoutIdRef = useRef<number>();
+  const timeoutIdRef = useRef<number | undefined>(undefined);
   const { wait, immediate } = options ?? {};
 
   const debounceCallback = useCallback(

src/app/hooks/useFileDrop.ts

@@ -14,7 +14,7 @@ export const useFileDropZone = (
   zoneRef: RefObject<HTMLElement>,
   onDrop: (file: File[]) => void,
 ): boolean => {
-  const dragStateRef = useRef<'start' | 'leave' | 'over'>();
+  const dragStateRef = useRef<'start' | 'leave' | 'over' | undefined>(undefined);
   const [active, setActive] = useState(false);
 
   useEffect(() => {

src/app/hooks/useForceUpdate.ts

@@ -3,7 +3,7 @@ import { useReducer } from 'react';
 const reducer = (prevCount: number): number => prevCount + 1;
 
 export const useForceUpdate = (): [number, () => void] => {
-  const [state, dispatch] = useReducer<typeof reducer>(reducer, 0);
+  const [state, dispatch] = useReducer(reducer, 0);
 
   return [state, dispatch];
 };

src/app/hooks/useThrottle.ts

@@ -11,8 +11,8 @@ export function useThrottle<T extends unknown[]>(
   callback: ThrottleCallback<T>,
   options?: ThrottleOptions,
 ): ThrottleCallback<T> {
-  const timeoutIdRef = useRef<number>();
+  const timeoutIdRef = useRef<number | undefined>(undefined);
-  const argsRef = useRef<T>();
+  const argsRef = useRef<T | undefined>(undefined);
   const { wait, immediate } = options ?? {};
 
   const debounceCallback = useCallback(

src/app/hooks/useVirtualPaginator.ts

@@ -166,16 +166,22 @@ export const useVirtualPaginator = <TScrollElement extends HTMLElement>(
 
   const initialRenderRef = useRef(true);
 
-  const restoreScrollRef = useRef<{
+  const restoreScrollRef = useRef<
-    scrollTop: number;
+    | {
-    anchorOffsetTop: number;
+        scrollTop: number;
-    anchorItem: number;
+        anchorOffsetTop: number;
-  }>();
+        anchorItem: number;
+      }
+    | undefined
+  >(undefined);
 
-  const scrollToItemRef = useRef<{
+  const scrollToItemRef = useRef<
-    index: number;
+    | {
-    opts?: ScrollToOptions;
+        index: number;
-  }>();
+        opts?: ScrollToOptions;
+      }
+    | undefined
+  >(undefined);
 
   const propRef = useRef({
     range,

src/app/pages/client/ClientNonUIFeatures.tsx

@@ -130,7 +130,7 @@ function InviteNotifications() {
 
 function MessageNotifications() {
   const audioRef = useRef<HTMLAudioElement>(null);
-  const notifRef = useRef<Notification>();
+  const notifRef = useRef<Notification | undefined>(undefined);
   const unreadCacheRef = useRef<Map<string, UnreadInfo>>(new Map());
   const mx = useMatrixClient();
   const useAuthentication = useMediaAuthentication();

src/app/pages/client/SidebarNav.tsx

@@ -20,7 +20,7 @@ import {
 import { CreateTab } from './sidebar/CreateTab';
 
 export function SidebarNav() {
-  const scrollRef = useRef<HTMLDivElement>(null);
+  const scrollRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
 
   return (
     <Sidebar>

src/app/pages/client/explore/Server.tsx

@@ -355,8 +355,8 @@ export function PublicRooms() {
   const [searchParams] = useSearchParams();
   const serverSearchParams = useServerSearchParams(searchParams);
   const isSearch = !!serverSearchParams.term;
-  const scrollRef = useRef<HTMLDivElement>(null);
+  const scrollRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
-  const searchInputRef = useRef<HTMLInputElement>(null);
+  const searchInputRef = useRef<HTMLInputElement>(null) as React.RefObject<HTMLInputElement>;
   const navigate = useNavigate();
   const roomTypeFilters = useRoomTypeFilters();
 

src/app/pages/client/home/Search.tsx

@@ -7,7 +7,7 @@ import { ScreenSize, useScreenSizeContext } from '../../../hooks/useScreenSize';
 import { BackRouteHandler } from '../../../components/BackRouteHandler';
 
 export function HomeSearch() {
-  const scrollRef = useRef<HTMLDivElement>(null);
+  const scrollRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
   const rooms = useHomeRooms();
   const screenSize = useScreenSizeContext();
 

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

@@ -575,8 +575,8 @@ export function Notifications() {
   const { navigateRoom } = useRoomNavigate();
   const [searchParams, setSearchParams] = useSearchParams();
   const notificationsSearchParams = useNotificationsSearchParams(searchParams);
-  const scrollRef = useRef<HTMLDivElement>(null);
+  const scrollRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
-  const scrollTopAnchorRef = useRef<HTMLDivElement>(null);
+  const scrollTopAnchorRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
   const [refreshIntervalTime, setRefreshIntervalTime] = useState(DEFAULT_REFRESH_MS);
 
   const onlyHighlight = notificationsSearchParams.only === 'highlight';

src/app/pages/client/sidebar/SpaceTabs.tsx

@@ -402,7 +402,7 @@ function SpaceTab({
 }: SpaceTabProps) {
   const mx = useMatrixClient();
   const useAuthentication = useMediaAuthentication();
-  const targetRef = useRef<HTMLDivElement>(null);
+  const targetRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
 
   const spaceDraggable: SidebarDraggable = useMemo(
     () =>
@@ -506,8 +506,8 @@ type OpenedSpaceFolderProps = {
   children?: ReactNode;
 };
 function OpenedSpaceFolder({ folder, onClose, children }: OpenedSpaceFolderProps) {
-  const aboveTargetRef = useRef<HTMLDivElement>(null);
+  const aboveTargetRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
-  const belowTargetRef = useRef<HTMLDivElement>(null);
+  const belowTargetRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
 
   const spaceDraggable: SidebarDraggable = useMemo(() => ({ folder, open: true }), [folder]);
 
@@ -554,7 +554,7 @@ function ClosedSpaceFolder({
 }: ClosedSpaceFolderProps) {
   const mx = useMatrixClient();
   const useAuthentication = useMediaAuthentication();
-  const handlerRef = useRef<HTMLDivElement>(null);
+  const handlerRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
 
   const spaceDraggable: FolderDraggable = useMemo(() => ({ folder }), [folder]);
   useDraggableItem(spaceDraggable, handlerRef, onDragging);

src/app/pages/client/space/Search.tsx

@@ -14,7 +14,7 @@ import { BackRouteHandler } from '../../../components/BackRouteHandler';
 
 export function SpaceSearch() {
   const mx = useMatrixClient();
-  const scrollRef = useRef<HTMLDivElement>(null);
+  const scrollRef = useRef<HTMLDivElement>(null) as React.RefObject<HTMLDivElement>;
   const space = useSpace();
   const screenSize = useScreenSizeContext();
 

src/app/plugins/react-custom-html-parser.tsx

@@ -1,5 +1,6 @@
 /* eslint-disable jsx-a11y/alt-text */
 import React, {
+  type JSX,
   ComponentPropsWithoutRef,
   ReactEventHandler,
   Suspense,