Iterate

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

.eslintrc.js

@@ -1,5 +1,5 @@
 module.exports = {
-    plugins: ["matrix-org"],
+    plugins: ["matrix-org", "eslint-plugin-react-compiler"],
     extends: ["plugin:matrix-org/babel", "plugin:matrix-org/react", "plugin:matrix-org/a11y"],
     parserOptions: {
         project: ["./tsconfig.json"],
@@ -170,6 +170,8 @@ module.exports = {
         "jsx-a11y/role-supports-aria-props": "off",
 
         "matrix-org/require-copyright-header": "error",
+
+        "react-compiler/react-compiler": "error",
     },
     overrides: [
         {
@@ -262,6 +264,7 @@ module.exports = {
 
                 // These are fine in tests
                 "no-restricted-globals": "off",
+                "react-compiler/react-compiler": "off",
             },
         },
         {

__mocks__/maplibre-gl.js

@@ -17,6 +17,7 @@ class MockMap extends EventEmitter {
     setCenter = jest.fn();
     setStyle = jest.fn();
     fitBounds = jest.fn();
+    remove = jest.fn();
 }
 const MockMapInstance = new MockMap();
 

package.json

@@ -233,6 +233,7 @@
         "eslint-plugin-jsx-a11y": "^6.5.1",
         "eslint-plugin-matrix-org": "^2.0.2",
         "eslint-plugin-react": "^7.28.0",
+        "eslint-plugin-react-compiler": "^19.0.0-beta-df7b47d-20241124",
         "eslint-plugin-react-hooks": "^5.0.0",
         "eslint-plugin-unicorn": "^56.0.0",
         "express": "^4.18.2",

src/accessibility/RovingTabIndex.tsx

@@ -392,6 +392,7 @@ export const useRovingTabIndex = <T extends HTMLElement>(
         });
     }, []); // eslint-disable-line react-hooks/exhaustive-deps
 
+    // eslint-disable-next-line react-compiler/react-compiler
     const isActive = context.state.activeNode === nodeRef.current;
     return [onFocus, isActive, ref, nodeRef];
 };

src/components/structures/AutocompleteInput.tsx

@@ -142,6 +142,7 @@ export const AutocompleteInput: React.FC<AutocompleteInputProps> = ({
             {isFocused && suggestions.length ? (
                 <div
                     className="mx_AutocompleteInput_matches"
+                    // eslint-disable-next-line react-compiler/react-compiler
                     style={{ top: editorContainerRef.current?.clientHeight }}
                     data-testid="autocomplete-matches"
                 >

src/components/structures/ContextMenu.tsx

@@ -607,6 +607,7 @@ export const useContextMenu = <T extends any = HTMLElement>(inputRef?: RefObject
         setIsOpen(false);
     };
 
+    // eslint-disable-next-line react-compiler/react-compiler
     return [button.current ? isOpen : false, button, open, close, setIsOpen];
 };
 

src/components/structures/FilePanel.tsx

@@ -286,9 +286,7 @@ class FilePanel extends React.Component<IProps, IState> {
                         ref={this.card}
                         header={_t("right_panel|files_button")}
                     >
-                        {this.card.current && (
-                            <Measured sensor={this.card.current} onMeasurement={this.onMeasurement} />
-                        )}
+                        <Measured sensor={this.card} onMeasurement={this.onMeasurement} />
                         <SearchWarning isRoomEncrypted={isRoomEncrypted} kind={WarningKind.Files} />
                         <TimelinePanel
                             manageReadReceipts={false}

src/components/structures/NotificationPanel.tsx

@@ -95,7 +95,7 @@ export default class NotificationPanel extends React.PureComponent<IProps, IStat
                     onClose={this.props.onClose}
                     withoutScrollContainer={true}
                 >
-                    {this.card.current && <Measured sensor={this.card.current} onMeasurement={this.onMeasurement} />}
+                    <Measured sensor={this.card} onMeasurement={this.onMeasurement} />
                     {content}
                 </BaseCard>
             </ScopedRoomContextProvider>

src/components/structures/RoomSearchView.tsx

@@ -6,7 +6,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
 Please see LICENSE files in the repository root for full details.
 */
 
-import React, { forwardRef, useCallback, useContext, useEffect, useRef, useState } from "react";
+import React, { forwardRef, useCallback, useContext, useEffect, useMemo, useRef, useState } from "react";
 import {
     ISearchResults,
     IThreadBundledRelationship,
@@ -58,7 +58,7 @@ export const RoomSearchView = forwardRef<ScrollPanel, Props>(
         const [results, setResults] = useState<ISearchResults | null>(null);
         const aborted = useRef(false);
         // A map from room ID to permalink creator
-        const permalinkCreators = useRef(new Map<string, RoomPermalinkCreator>()).current;
+        const permalinkCreators = useMemo(() => new Map<string, RoomPermalinkCreator>(), []);
         const innerRef = useRef<ScrollPanel | null>();
 
         useEffect(() => {

src/components/structures/RoomView.tsx

@@ -273,6 +273,7 @@ function LocalRoomView(props: LocalRoomViewProps): ReactElement {
     }
 
     const onRetryClicked = (): void => {
+        // eslint-disable-next-line react-compiler/react-compiler
         room.state = LocalRoomState.NEW;
         defaultDispatcher.dispatch({
             action: "local_room_event",
@@ -2514,9 +2515,7 @@ export class RoomView extends React.Component<IRoomProps, IRoomState> {
                 mainSplitContentClassName = "mx_MainSplit_timeline";
                 mainSplitBody = (
                     <>
-                        {this.roomViewBody.current && (
-                            <Measured sensor={this.roomViewBody.current} onMeasurement={this.onMeasurement} />
-                        )}
+                        <Measured sensor={this.roomViewBody} onMeasurement={this.onMeasurement} />
                         {auxPanel}
                         {pinnedMessageBanner}
                         <main className={timelineClasses}>

src/components/structures/ThreadPanel.tsx

@@ -204,7 +204,7 @@ const ThreadPanel: React.FC<IProps> = ({ roomId, onClose, permalinkCreator }) =>
                 ref={card}
                 closeButtonRef={closeButonRef}
             >
-                {card.current && <Measured sensor={card.current} onMeasurement={setNarrow} />}
+                <Measured sensor={card} onMeasurement={setNarrow} />
                 {timelineSet ? (
                     <TimelinePanel
                         key={filterOption + ":" + (timelineSet.getFilter()?.filterId ?? roomId)}

src/components/structures/ThreadView.tsx

@@ -443,7 +443,7 @@ export default class ThreadView extends React.Component<IProps, IState> {
                         PosthogTrackers.trackInteraction("WebThreadViewBackButton", ev);
                     }}
                 >
-                    {this.card.current && <Measured sensor={this.card.current} onMeasurement={this.onMeasurement} />}
+                    <Measured sensor={this.card} onMeasurement={this.onMeasurement} />
                     <div className="mx_ThreadView_timelinePanelWrapper">{timeline}</div>
 
                     {ContentMessages.sharedInstance().getCurrentUploads(threadRelation).length > 0 && (

src/components/utils/Box.tsx

@@ -7,7 +7,7 @@ Please see LICENSE files in the repository root for full details.
 */
 
 import classNames from "classnames";
-import React, { useEffect, useRef } from "react";
+import React, { useMemo } from "react";
 
 type FlexProps = {
     /**
@@ -40,25 +40,6 @@ type FlexProps = {
     grow?: string | null;
 };
 
-/**
- * Set or remove a CSS property
- * @param ref the reference
- * @param name the CSS property name
- * @param value the CSS property value
- */
-function addOrRemoveProperty(
-    ref: React.MutableRefObject<HTMLElement | undefined>,
-    name: string,
-    value?: string | null,
-): void {
-    const style = ref.current!.style;
-    if (value) {
-        style.setProperty(name, value);
-    } else {
-        style.removeProperty(name);
-    }
-}
-
 /**
  * A flex child helper
  */
@@ -71,12 +52,12 @@ export function Box({
     children,
     ...props
 }: React.PropsWithChildren<FlexProps>): JSX.Element {
-    const ref = useRef<HTMLElement>();
-
-    useEffect(() => {
-        addOrRemoveProperty(ref, `--mx-box-flex`, flex);
-        addOrRemoveProperty(ref, `--mx-box-shrink`, shrink);
-        addOrRemoveProperty(ref, `--mx-box-grow`, grow);
+    const style = useMemo(() => {
+        const style: Record<string, any> = {};
+        if (flex) style["--mx-box-flex"] = flex;
+        if (shrink) style["--mx-box-shrink"] = shrink;
+        if (grow) style["--mx-box-grow"] = grow;
+        return style;
     }, [flex, grow, shrink]);
 
     return React.createElement(
@@ -88,7 +69,7 @@ export function Box({
                 "mx_Box--shrink": !!shrink,
                 "mx_Box--grow": !!grow,
             }),
-            ref,
+            style,
         },
         children,
     );

src/components/utils/Flex.tsx

@@ -7,7 +7,7 @@ Please see LICENSE files in the repository root for full details.
 */
 
 import classNames from "classnames";
-import React, { useEffect, useRef } from "react";
+import React, { useMemo } from "react";
 
 type FlexProps = {
     /**
@@ -64,15 +64,16 @@ export function Flex({
     children,
     ...props
 }: React.PropsWithChildren<FlexProps>): JSX.Element {
-    const ref = useRef<HTMLElement>();
+    const style = useMemo(
+        () => ({
+            "--mx-flex-display": display,
+            "--mx-flex-direction": direction,
+            "--mx-flex-align": align,
+            "--mx-flex-justify": justify,
+            "--mx-flex-gap": gap,
+        }),
+        [align, direction, display, gap, justify],
+    );
 
-    useEffect(() => {
-        ref.current!.style.setProperty(`--mx-flex-display`, display);
-        ref.current!.style.setProperty(`--mx-flex-direction`, direction);
-        ref.current!.style.setProperty(`--mx-flex-align`, align);
-        ref.current!.style.setProperty(`--mx-flex-justify`, justify);
-        ref.current!.style.setProperty(`--mx-flex-gap`, gap);
-    }, [align, direction, display, gap, justify]);
-
-    return React.createElement(as, { ...props, className: classNames("mx_Flex", className), ref }, children);
+    return React.createElement(as, { ...props, className: classNames("mx_Flex", className), style }, children);
 }

src/components/views/elements/EffectsOverlay.tsx

@@ -58,11 +58,10 @@ const EffectsOverlay: FunctionComponent<IProps> = ({ roomWidth }) => {
         if (canvas) canvas.height = UIStore.instance.windowHeight;
         UIStore.instance.on(UI_EVENTS.Resize, resize);
 
+        const currentEffects = effectsRef.current; // this is not a react node ref, warning can be safely ignored
         return () => {
             dis.unregister(dispatcherRef);
             UIStore.instance.off(UI_EVENTS.Resize, resize);
-            // eslint-disable-next-line react-hooks/exhaustive-deps
-            const currentEffects = effectsRef.current; // this is not a react node ref, warning can be safely ignored
             for (const effect in currentEffects) {
                 const effectModule: ICanvasEffect = currentEffects.get(effect)!;
                 if (effectModule && effectModule.isRunning) {

src/components/views/elements/Measured.tsx

@@ -6,12 +6,12 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
 Please see LICENSE files in the repository root for full details.
 */
 
-import React from "react";
+import React, { RefObject } from "react";
 
 import UIStore, { UI_EVENTS } from "../../../stores/UIStore";
 
 interface IProps {
-    sensor: Element;
+    sensor: RefObject<Element>;
     breakpoint: number;
     onMeasurement(narrow: boolean): void;
 }
@@ -35,14 +35,14 @@ export default class Measured extends React.PureComponent<IProps> {
     }
 
     public componentDidUpdate(prevProps: Readonly<IProps>): void {
-        const previous = prevProps.sensor;
-        const current = this.props.sensor;
+        const previous = prevProps.sensor.current;
+        const current = this.props.sensor.current;
         if (previous === current) return;
         if (previous) {
             UIStore.instance.stopTrackingElementDimensions(`Measured${this.instanceId}`);
         }
         if (current) {
-            UIStore.instance.trackElementDimensions(`Measured${this.instanceId}`, this.props.sensor);
+            UIStore.instance.trackElementDimensions(`Measured${this.instanceId}`, this.props.sensor.current);
         }
     }
 

src/components/views/right_panel/TimelineCard.tsx

@@ -213,7 +213,7 @@ export default class TimelineCard extends React.Component<IProps, IState> {
                     header={_t("right_panel|video_room_chat|title")}
                     ref={this.card}
                 >
-                    {this.card.current && <Measured sensor={this.card.current} onMeasurement={this.onMeasurement} />}
+                    <Measured sensor={this.card} onMeasurement={this.onMeasurement} />
                     <div className="mx_TimelineCard_timeline">
                         {jumpToBottom}
                         <TimelinePanel

src/components/views/rooms/ReadReceiptGroup.tsx

@@ -109,6 +109,7 @@ export function ReadReceiptGroup({
                 readReceiptPosition = readReceiptMap[userId];
                 if (!readReceiptPosition) {
                     readReceiptPosition = {};
+                    // eslint-disable-next-line react-compiler/react-compiler
                     readReceiptMap[userId] = readReceiptPosition;
                 }
             }

src/components/views/rooms/UserIdentityWarning.tsx

@@ -5,7 +5,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
 Please see LICENSE files in the repository root for full details.
 */
 
-import React, { useCallback, useRef, useState } from "react";
+import React, { useCallback, useEffect, useRef, useState } from "react";
 import { EventType, KnownMembership, MatrixEvent, Room, RoomStateEvent, RoomMember } from "matrix-js-sdk/src/matrix";
 import { CryptoApi, CryptoEvent, UserVerificationStatus } from "matrix-js-sdk/src/crypto-api";
 import { logger } from "matrix-js-sdk/src/logger";
@@ -213,9 +213,11 @@ export const UserIdentityWarning: React.FC<UserIdentityWarningProps> = ({ room }
         initialisedRef.current = InitialisationStatus.Completed;
     }, [crypto, room, addMembersWhoNeedApproval, updateCurrentPrompt]);
 
-    loadMembers().catch((e) => {
-        logger.error("Error initialising UserIdentityWarning:", e);
-    });
+    useEffect(() => {
+        loadMembers().catch((e) => {
+            logger.error("Error initialising UserIdentityWarning:", e);
+        });
+    }, [loadMembers]);
 
     // When a user's verification status changes, we check if they need to be
     // added/removed from the set of members needing approval.

src/components/views/rooms/wysiwyg_composer/EditWysiwygComposer.tsx

@@ -6,7 +6,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
 Please see LICENSE files in the repository root for full details.
 */
 
-import React, { ForwardedRef, forwardRef, MutableRefObject, useRef } from "react";
+import React, { ForwardedRef, forwardRef, MutableRefObject, useMemo } from "react";
 import classNames from "classnames";
 
 import EditorStateTransfer from "../../../../utils/EditorStateTransfer";
@@ -44,7 +44,7 @@ export default function EditWysiwygComposer({
     className,
     ...props
 }: EditWysiwygComposerProps): JSX.Element {
-    const defaultContextValue = useRef(getDefaultContextValue({ editorStateTransfer }));
+    const defaultContextValue = useMemo(() => getDefaultContextValue({ editorStateTransfer }), [editorStateTransfer]);
     const initialContent = useInitialContent(editorStateTransfer);
     const isReady = !editorStateTransfer || initialContent !== undefined;
 
@@ -55,7 +55,7 @@ export default function EditWysiwygComposer({
     }
 
     return (
-        <ComposerContext.Provider value={defaultContextValue.current}>
+        <ComposerContext.Provider value={defaultContextValue}>
             <WysiwygComposer
                 className={classNames("mx_EditWysiwygComposer", className)}
                 initialContent={initialContent}

src/components/views/rooms/wysiwyg_composer/SendWysiwygComposer.tsx

@@ -6,7 +6,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
 Please see LICENSE files in the repository root for full details.
 */
 
-import React, { ForwardedRef, forwardRef, MutableRefObject, useRef } from "react";
+import React, { ForwardedRef, forwardRef, MutableRefObject, useMemo } from "react";
 import { IEventRelation } from "matrix-js-sdk/src/matrix";
 
 import { useWysiwygSendActionHandler } from "./hooks/useWysiwygSendActionHandler";
@@ -52,10 +52,13 @@ export default function SendWysiwygComposer({
     ...props
 }: SendWysiwygComposerProps): JSX.Element {
     const Composer = isRichTextEnabled ? WysiwygComposer : PlainTextComposer;
-    const defaultContextValue = useRef(getDefaultContextValue({ eventRelation: props.eventRelation }));
+    const defaultContextValue = useMemo(
+        () => getDefaultContextValue({ eventRelation: props.eventRelation }),
+        [props.eventRelation],
+    );
 
     return (
-        <ComposerContext.Provider value={defaultContextValue.current}>
+        <ComposerContext.Provider value={defaultContextValue}>
             <Composer
                 className="mx_SendWysiwygComposer"
                 leftComponent={e2eStatus && <E2EIcon status={e2eStatus} />}

src/components/views/rooms/wysiwyg_composer/hooks/useComposerFunctions.ts

@@ -21,6 +21,7 @@ export function useComposerFunctions(
         () => ({
             clear: () => {
                 if (ref.current) {
+                    // eslint-disable-next-line react-compiler/react-compiler
                     ref.current.innerHTML = "";
                 }
             },

src/components/views/rooms/wysiwyg_composer/hooks/usePlainTextInitialization.ts

@@ -12,6 +12,7 @@ export function usePlainTextInitialization(initialContent = "", ref: RefObject<H
     useEffect(() => {
         // always read and write the ref.current using .innerHTML for consistency in linebreak and HTML entity handling
         if (ref.current) {
+            // eslint-disable-next-line react-compiler/react-compiler
             ref.current.innerHTML = initialContent;
         }
     }, [ref, initialContent]);

src/components/views/settings/ThemeChoicePanel.tsx

@@ -6,7 +6,7 @@
  * Please see LICENSE files in the repository root for full details.
  */
 
-import React, { ChangeEvent, JSX, useCallback, useMemo, useRef, useState } from "react";
+import React, { ChangeEvent, JSX, useCallback, useMemo, useState } from "react";
 import {
     InlineField,
     ToggleControl,
@@ -39,12 +39,12 @@ import { useSettingValue } from "../../../hooks/useSettings";
  */
 export function ThemeChoicePanel(): JSX.Element {
     const themeState = useTheme();
-    const themeWatcher = useRef(new ThemeWatcher());
+    const themeWatcher = useMemo(() => new ThemeWatcher(), []);
     const customThemeEnabled = useSettingValue<boolean>("feature_custom_themes");
 
     return (
         <SettingsSubsection heading={_t("common|theme")} legacy={false} data-testid="themePanel">
-            {themeWatcher.current.isSystemThemeSupported() && (
+            {themeWatcher.isSystemThemeSupported() && (
                 <SystemTheme systemThemeActivated={themeState.systemThemeActivated} />
             )}
             <ThemeSelectors theme={themeState.theme} disabled={themeState.systemThemeActivated} />

src/components/views/settings/tabs/room/VoipRoomSettingsTab.tsx

@@ -8,6 +8,7 @@ Please see LICENSE files in the repository root for full details.
 
 import React, { useCallback, useMemo, useState } from "react";
 import { JoinRule, EventType, RoomState, Room } from "matrix-js-sdk/src/matrix";
+import { RoomPowerLevelsEventContent } from "matrix-js-sdk/src/types";
 
 import { _t } from "../../../../../languageHandler";
 import LabelledToggleSwitch from "../../../elements/LabelledToggleSwitch";
@@ -24,48 +25,49 @@ interface ElementCallSwitchProps {
 
 const ElementCallSwitch: React.FC<ElementCallSwitchProps> = ({ room }) => {
     const isPublic = useMemo(() => room.getJoinRule() === JoinRule.Public, [room]);
-    const [content, events, maySend] = useRoomState(
+    const [content, maySend] = useRoomState(
         room,
         useCallback(
             (state: RoomState) => {
-                const content = state?.getStateEvents(EventType.RoomPowerLevels, "")?.getContent();
+                const content = state
+                    ?.getStateEvents(EventType.RoomPowerLevels, "")
+                    ?.getContent<RoomPowerLevelsEventContent>();
                 return [
                     content ?? {},
-                    content?.["events"] ?? {},
                     state?.maySendStateEvent(EventType.RoomPowerLevels, room.client.getSafeUserId()),
-                ];
+                ] as const;
             },
             [room.client],
         ),
     );
 
     const [elementCallEnabled, setElementCallEnabled] = useState<boolean>(() => {
-        return events[ElementCall.MEMBER_EVENT_TYPE.name] === 0;
+        return content.events?.[ElementCall.MEMBER_EVENT_TYPE.name] === 0;
     });
 
     const onChange = useCallback(
         (enabled: boolean): void => {
             setElementCallEnabled(enabled);
 
+            // Take a copy to avoid mutating the original
+            const newContent = { events: {}, ...content };
+
             if (enabled) {
-                const userLevel = events[EventType.RoomMessage] ?? content.users_default ?? 0;
+                const userLevel = newContent.events[EventType.RoomMessage] ?? content.users_default ?? 0;
                 const moderatorLevel = content.kick ?? 50;
 
-                events[ElementCall.CALL_EVENT_TYPE.name] = isPublic ? moderatorLevel : userLevel;
-                events[ElementCall.MEMBER_EVENT_TYPE.name] = userLevel;
+                newContent.events[ElementCall.CALL_EVENT_TYPE.name] = isPublic ? moderatorLevel : userLevel;
+                newContent.events[ElementCall.MEMBER_EVENT_TYPE.name] = userLevel;
             } else {
-                const adminLevel = events[EventType.RoomPowerLevels] ?? content.state_default ?? 100;
+                const adminLevel = newContent.events[EventType.RoomPowerLevels] ?? content.state_default ?? 100;
 
-                events[ElementCall.CALL_EVENT_TYPE.name] = adminLevel;
-                events[ElementCall.MEMBER_EVENT_TYPE.name] = adminLevel;
+                newContent.events[ElementCall.CALL_EVENT_TYPE.name] = adminLevel;
+                newContent.events[ElementCall.MEMBER_EVENT_TYPE.name] = adminLevel;
             }
 
-            room.client.sendStateEvent(room.roomId, EventType.RoomPowerLevels, {
-                events: events,
-                ...content,
-            });
+            room.client.sendStateEvent(room.roomId, EventType.RoomPowerLevels, newContent);
         },
-        [room.client, room.roomId, content, events, isPublic],
+        [room.client, room.roomId, content, isPublic],
     );
 
     const brand = SdkConfig.get("element_call").brand ?? DEFAULTS.element_call.brand;

src/components/views/spaces/QuickThemeSwitcher.tsx

@@ -27,7 +27,7 @@ type Props = {
 const MATCH_SYSTEM_THEME_ID = "MATCH_SYSTEM_THEME_ID";
 
 const QuickThemeSwitcher: React.FC<Props> = ({ requestClose }) => {
-    const orderedThemes = useMemo(getOrderedThemes, []);
+    const orderedThemes = useMemo(() => getOrderedThemes(), []);
 
     const themeState = useTheme();
     const nonHighContrast = findNonHighContrastTheme(themeState.theme);

src/components/views/spaces/threads-activity-centre/useUnreadThreadRooms.ts

@@ -6,7 +6,7 @@
  * Please see LICENSE files in the repository root for full details.
  */
 
-import { useCallback, useEffect, useState } from "react";
+import { useCallback, useEffect, useMemo, useState } from "react";
 import { ClientEvent, MatrixClient, MatrixEventEvent, Room } from "matrix-js-sdk/src/matrix";
 import { throttle } from "lodash";
 
@@ -42,14 +42,12 @@ export function useUnreadThreadRooms(forceComputation: boolean): Result {
         setResult(computeUnreadThreadRooms(mxClient, msc3946ProcessDynamicPredecessor, settingTACOnlyNotifs));
     }, [mxClient, msc3946ProcessDynamicPredecessor, settingTACOnlyNotifs]);
 
-    // The exhautive deps lint rule can't compute dependencies here since it's not a plain inline func.
-    // We make this as simple as possible so its only dep is doUpdate itself.
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-    const scheduleUpdate = useCallback(
-        throttle(doUpdate, MIN_UPDATE_INTERVAL_MS, {
-            leading: false,
-            trailing: true,
-        }),
+    const scheduleUpdate = useMemo(
+        () =>
+            throttle(doUpdate, MIN_UPDATE_INTERVAL_MS, {
+                leading: false,
+                trailing: true,
+            }),
         [doUpdate],
     );
 

src/contexts/ScopedRoomContext.tsx

@@ -7,7 +7,7 @@ Please see LICENSE files in the repository root for full details.
 */
 
 import { TypedEventEmitter } from "matrix-js-sdk/src/matrix";
-import React, { ContextType, createContext, memo, ReactNode, useContext, useEffect, useRef, useState } from "react";
+import React, { ContextType, createContext, memo, ReactNode, useContext, useEffect, useMemo, useState } from "react";
 
 import { objectKeyChanges } from "../utils/objects.ts";
 import { useTypedEventEmitter } from "../hooks/useEventEmitter.ts";
@@ -48,15 +48,16 @@ const ScopedRoomContext = createContext<EfficientContext<ContextValue> | undefin
 // Uses react memo and leverages splatting the value to ensure that the context is only updated when the state changes (shallow compare)
 export const ScopedRoomContextProvider = memo(
     ({ children, ...state }: { children: ReactNode } & ContextValue): JSX.Element => {
-        const contextRef = useRef(new EfficientContext<ContextValue>(state));
+        // eslint-disable-next-line react-compiler/react-compiler,react-hooks/exhaustive-deps
+        const context = useMemo(() => new EfficientContext<ContextValue>(state), []);
         useEffect(() => {
-            contextRef.current.setState(state);
-        }, [state]);
+            context.setState(state);
+        }, [context, state]);
 
         // Includes the legacy RoomContext provider for backwards compatibility with class components
         return (
             <RoomContext.Provider value={state}>
-                <ScopedRoomContext.Provider value={contextRef.current}>{children}</ScopedRoomContext.Provider>
+                <ScopedRoomContext.Provider value={context}>{children}</ScopedRoomContext.Provider>
             </RoomContext.Provider>
         );
     },

src/contexts/ToastContext.tsx

@@ -6,7 +6,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
 Please see LICENSE files in the repository root for full details.
 */
 
-import { ReactNode, createContext, useCallback, useContext, useEffect, useRef, useState } from "react";
+import { ReactNode, createContext, useCallback, useContext, useEffect, useState, useMemo } from "react";
 
 /**
  * A ToastContext helps components display any kind of toast message and can be provided
@@ -33,19 +33,19 @@ export function useToastContext(): ToastRack {
  * the ToastRack object that should be provided to the context
  */
 export function useActiveToast(): [ReactNode | undefined, ToastRack] {
-    const toastRack = useRef(new ToastRack());
+    const toastRack = useMemo(() => new ToastRack(), []);
 
-    const [activeToast, setActiveToast] = useState<ReactNode | undefined>(toastRack.current.getActiveToast());
+    const [activeToast, setActiveToast] = useState<ReactNode | undefined>(toastRack.getActiveToast());
 
     const updateCallback = useCallback(() => {
-        setActiveToast(toastRack.current.getActiveToast());
+        setActiveToast(toastRack.getActiveToast());
     }, [setActiveToast, toastRack]);
 
     useEffect(() => {
-        toastRack.current.setCallback(updateCallback);
+        toastRack.setCallback(updateCallback);
     }, [toastRack, updateCallback]);
 
-    return [activeToast, toastRack.current];
+    return [activeToast, toastRack];
 }
 
 interface DisplayedToast {

src/hooks/useAsyncRefreshMemo.ts

@@ -34,7 +34,7 @@ export function useAsyncRefreshMemo<T>(fn: Fn<T>, deps: DependencyList, initialV
         return () => {
             discard = true;
         };
-    }, deps); // eslint-disable-line react-hooks/exhaustive-deps
+    }, deps); // eslint-disable-line react-hooks/exhaustive-deps,react-compiler/react-compiler
     useEffect(refresh, [refresh]);
     return [value, refresh];
 }

src/hooks/useRoomNotificationState.ts

@@ -25,6 +25,7 @@ export const useNotificationState = (room: Room): [RoomNotifState | undefined, (
             setNotificationState(echoChamber.notificationVolume);
         }
     });
+    // eslint-disable-next-line react-compiler/react-compiler
     const setter = useCallback((state: RoomNotifState) => (echoChamber.notificationVolume = state), [echoChamber]);
     return [notificationState, setter];
 };

src/hooks/useTransition.ts

@@ -22,6 +22,6 @@ export const useTransition = <D extends DependencyList>(callback: (...params: D)
     useEffect(() => {
         if (args.current !== null) func.current(...args.current);
         args.current = deps;
-        // eslint-disable-next-line react-hooks/exhaustive-deps
+        // eslint-disable-next-line react-compiler/react-compiler,react-hooks/exhaustive-deps
     }, deps);
 };

src/hooks/useUserOnboardingContext.ts

@@ -35,6 +35,7 @@ const USER_ONBOARDING_CONTEXT_INTERVAL = 5000;
  */
 function useRefOf<T extends any[], R>(value: (...values: T) => R): (...values: T) => R {
     const ref = useRef(value);
+    // eslint-disable-next-line react-compiler/react-compiler
     ref.current = value;
     return useCallback((...values: T) => ref.current(...values), []);
 }

src/utils/location/useMap.ts

@@ -6,7 +6,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
 Please see LICENSE files in the repository root for full details.
 */
 
-import { useEffect, useState } from "react";
+import { useEffect, useMemo } from "react";
 
 import type { Map as MapLibreMap } from "maplibre-gl";
 import { createMap } from "./map";
@@ -26,29 +26,25 @@ interface UseMapProps {
  */
 export const useMap = ({ interactive, bodyId, onError }: UseMapProps): MapLibreMap | undefined => {
     const cli = useMatrixClientContext();
-    const [map, setMap] = useState<MapLibreMap>();
 
-    useEffect(
-        () => {
-            try {
-                setMap(createMap(cli, !!interactive, bodyId, onError));
-            } catch (error) {
-                console.error("Error encountered in useMap", error);
-                if (error instanceof Error) {
-                    onError?.(error);
-                }
+    const map = useMemo(() => {
+        try {
+            return createMap(cli, !!interactive, bodyId, onError);
+        } catch (error) {
+            console.error("Error encountered in useMap", error);
+            if (error instanceof Error) {
+                onError?.(error);
             }
-            return () => {
-                if (map) {
-                    map.remove();
-                    setMap(undefined);
-                }
-            };
-        },
-        // map is excluded as a dependency
-        // eslint-disable-next-line react-hooks/exhaustive-deps
-        [interactive, bodyId, onError],
-    );
+        }
+    }, [bodyId, cli, interactive, onError]);
+
+    // cleanup
+    useEffect(() => {
+        if (!map) return;
+        return () => {
+            map.remove();
+        };
+    }, [map]);
 
     return map;
 };

yarn.lock

@@ -61,7 +61,7 @@
   resolved "https://registry.yarnpkg.com/@babel/compat-data/-/compat-data-7.26.3.tgz#99488264a56b2aded63983abd6a417f03b92ed02"
   integrity sha512-nHIxvKPniQXpmQLb0vhY3VaFb3S0YrTAwpOWJZh1wn3oJPjJk9Asva204PsBdmAE8vpzfHudT8DB0scYvy9q0g==
 
-"@babel/core@^7.0.0", "@babel/core@^7.11.6", "@babel/core@^7.12.10", "@babel/core@^7.12.3", "@babel/core@^7.18.5", "@babel/core@^7.21.3", "@babel/core@^7.23.9":
+"@babel/core@^7.0.0", "@babel/core@^7.11.6", "@babel/core@^7.12.10", "@babel/core@^7.12.3", "@babel/core@^7.18.5", "@babel/core@^7.21.3", "@babel/core@^7.23.9", "@babel/core@^7.24.4":
   version "7.26.0"
   resolved "https://registry.yarnpkg.com/@babel/core/-/core-7.26.0.tgz#d78b6023cc8f3114ccf049eb219613f74a747b40"
   integrity sha512-i1SLeK+DzNnQ3LL/CswPCa/E5u4lh1k6IAEphON8F+cXt0t9euTshDru0q7/IqMa1PMPz5RnHuHscF8/ZJsStg==
@@ -308,7 +308,7 @@
   dependencies:
     "@babel/types" "^7.25.8"
 
-"@babel/parser@^7.25.9", "@babel/parser@^7.26.0", "@babel/parser@^7.26.3":
+"@babel/parser@^7.24.4", "@babel/parser@^7.25.9", "@babel/parser@^7.26.0", "@babel/parser@^7.26.3":
   version "7.26.3"
   resolved "https://registry.yarnpkg.com/@babel/parser/-/parser-7.26.3.tgz#8c51c5db6ddf08134af1ddbacf16aaab48bac234"
   integrity sha512-WJ/CvmY8Mea8iDXo6a7RK2wbmJITT5fN3BEkRuFlxVyNx8jOKIIhmC4fSkTcPcf8JyavbBwIe6OpiCOBXt/IcA==
@@ -5662,6 +5662,18 @@ eslint-plugin-matrix-org@^2.0.2:
   resolved "https://registry.yarnpkg.com/eslint-plugin-matrix-org/-/eslint-plugin-matrix-org-2.0.2.tgz#95b86b0f16704ab19740f7c3c62eae69e20365e6"
   integrity sha512-cQy5Rjeq6uyu1mLXlPZwEJdyM0NmclrnEz68y792FSuuxzMyJNNYLGDQ5CkYW8H+PrD825HUFZ34pNXnjMOzOw==
 
+eslint-plugin-react-compiler@^19.0.0-beta-df7b47d-20241124:
+  version "19.0.0-beta-df7b47d-20241124"
+  resolved "https://registry.yarnpkg.com/eslint-plugin-react-compiler/-/eslint-plugin-react-compiler-19.0.0-beta-df7b47d-20241124.tgz#468751d3a8a6781189405ee56b39b80545306df8"
+  integrity sha512-82PfnllC8jP/68KdLAbpWuYTcfmtGLzkqy2IW85WopKMTr+4rdQpp+lfliQ/QE79wWrv/dRoADrk3Pdhq25nTw==
+  dependencies:
+    "@babel/core" "^7.24.4"
+    "@babel/parser" "^7.24.4"
+    "@babel/plugin-transform-private-methods" "^7.25.9"
+    hermes-parser "^0.25.1"
+    zod "^3.22.4"
+    zod-validation-error "^3.0.3"
+
 eslint-plugin-react-hooks@^5.0.0:
   version "5.0.0"
   resolved "https://registry.yarnpkg.com/eslint-plugin-react-hooks/-/eslint-plugin-react-hooks-5.0.0.tgz#72e2eefbac4b694f5324154619fee44f5f60f101"
@@ -6639,6 +6651,18 @@ he@^1.2.0:
   resolved "https://registry.yarnpkg.com/he/-/he-1.2.0.tgz#84ae65fa7eafb165fddb61566ae14baf05664f0f"
   integrity sha512-F/1DnUGPopORZi0ni+CvrCgHQ5FyEAHRLSApuYWMmrbSwoN2Mn/7k+Gl38gJnR7yyDZk6WLXwiGod1JOWNDKGw==
 
+hermes-estree@0.25.1:
+  version "0.25.1"
+  resolved "https://registry.yarnpkg.com/hermes-estree/-/hermes-estree-0.25.1.tgz#6aeec17d1983b4eabf69721f3aa3eb705b17f480"
+  integrity sha512-0wUoCcLp+5Ev5pDW2OriHC2MJCbwLwuRx+gAqMTOkGKJJiBCLjtrvy4PWUGn6MIVefecRpzoOZ/UV6iGdOr+Cw==
+
+hermes-parser@^0.25.1:
+  version "0.25.1"
+  resolved "https://registry.yarnpkg.com/hermes-parser/-/hermes-parser-0.25.1.tgz#5be0e487b2090886c62bd8a11724cd766d5f54d1"
+  integrity sha512-6pEjquH3rqaI6cYAXYPcz9MS4rY6R4ngRgrgfDshRptUZIc3lw0MCIJIGDj9++mfySOuPTHB4nrSW99BCvOPIA==
+  dependencies:
+    hermes-estree "0.25.1"
+
 highlight.js@^11.3.1:
   version "11.10.0"
   resolved "https://registry.yarnpkg.com/highlight.js/-/highlight.js-11.10.0.tgz#6e3600dc4b33d6dc23d5bd94fbf72405f5892b92"