Enable @typescript-eslint/explicit-function-return-type in /src (#9788)

* Enable `@typescript-eslint/explicit-member-accessibility` on /src

* Prettier

* Enable `@typescript-eslint/explicit-function-return-type` in /src

* Fix types

* tsc strict fixes

* Delint

* Fix test

* Fix bad merge

src/settings/SettingsStore.ts

@@ -174,7 +174,7 @@ export default class SettingsStore {
 
         const watcherId = `${new Date().getTime()}_${SettingsStore.watcherCount++}_${settingName}_${roomId}`;
 
-        const localizedCallback = (changedInRoomId: string | null, atLevel: SettingLevel, newValAtLevel: any) => {
+        const localizedCallback = (changedInRoomId: string | null, atLevel: SettingLevel, newValAtLevel: any): void => {
             if (!SettingsStore.doesSettingSupportLevel(originalSettingName, atLevel)) {
                 logger.warn(
                     `Setting handler notified for an update of an invalid setting level: ` +
@@ -200,7 +200,7 @@ export default class SettingsStore {
      * @param {string} watcherReference The watcher reference (received from #watchSetting)
      * to cancel.
      */
-    public static unwatchSetting(watcherReference: string) {
+    public static unwatchSetting(watcherReference: string): void {
         if (!SettingsStore.watchers.has(watcherReference)) {
             logger.warn(`Ending non-existent watcher ID ${watcherReference}`);
             return;
@@ -218,12 +218,12 @@ export default class SettingsStore {
      * @param {string} settingName The setting name to monitor.
      * @param {String} roomId The room ID to monitor for changes in. Use null for all rooms.
      */
-    public static monitorSetting(settingName: string, roomId: string | null) {
+    public static monitorSetting(settingName: string, roomId: string | null): void {
         roomId = roomId || null; // the thing wants null specifically to work, so appease it.
 
         if (!this.monitors.has(settingName)) this.monitors.set(settingName, new Map());
 
-        const registerWatcher = () => {
+        const registerWatcher = (): void => {
             this.monitors.get(settingName).set(
                 roomId,
                 SettingsStore.watchSetting(
@@ -266,7 +266,7 @@ export default class SettingsStore {
      * The level to get the display name for; Defaults to 'default'.
      * @return {String} The display name for the setting, or null if not found.
      */
-    public static getDisplayName(settingName: string, atLevel = SettingLevel.DEFAULT) {
+    public static getDisplayName(settingName: string, atLevel = SettingLevel.DEFAULT): string {
         if (!SETTINGS[settingName] || !SETTINGS[settingName].displayName) return null;
 
         let displayName = SETTINGS[settingName].displayName;
@@ -295,7 +295,7 @@ export default class SettingsStore {
      * @param {string} settingName The setting to look up.
      * @return {boolean} True if the setting is a feature.
      */
-    public static isFeature(settingName: string) {
+    public static isFeature(settingName: string): boolean {
         if (!SETTINGS[settingName]) return false;
         return SETTINGS[settingName].isFeature;
     }
@@ -634,7 +634,7 @@ export default class SettingsStore {
      * @param {string} realSettingName The setting name to try and read.
      * @param {string} roomId Optional room ID to test the setting in.
      */
-    public static debugSetting(realSettingName: string, roomId: string) {
+    public static debugSetting(realSettingName: string, roomId: string): void {
         logger.log(`--- DEBUG ${realSettingName}`);
 
         // Note: we intentionally use JSON.stringify here to avoid the console masking the
@@ -646,7 +646,7 @@ export default class SettingsStore {
         logger.log(`--- default level order: ${JSON.stringify(LEVEL_ORDER)}`);
         logger.log(`--- registered handlers: ${JSON.stringify(Object.keys(LEVEL_HANDLERS))}`);
 
-        const doChecks = (settingName) => {
+        const doChecks = (settingName): void => {
             for (const handlerName of Object.keys(LEVEL_HANDLERS)) {
                 const handler = LEVEL_HANDLERS[handlerName];
 

src/settings/WatchManager.ts

@@ -29,14 +29,14 @@ export class WatchManager {
     private watchers = new Map<string, Map<string | symbol, CallbackFn[]>>(); // settingName -> roomId -> CallbackFn[]
 
     // Proxy for handlers to delegate changes to this manager
-    public watchSetting(settingName: string, roomId: string | null, cb: CallbackFn) {
+    public watchSetting(settingName: string, roomId: string | null, cb: CallbackFn): void {
         if (!this.watchers.has(settingName)) this.watchers.set(settingName, new Map());
         if (!this.watchers.get(settingName).has(roomId)) this.watchers.get(settingName).set(roomId, []);
         this.watchers.get(settingName).get(roomId).push(cb);
     }
 
     // Proxy for handlers to delegate changes to this manager
-    public unwatchSetting(cb: CallbackFn) {
+    public unwatchSetting(cb: CallbackFn): void {
         this.watchers.forEach((map) => {
             map.forEach((callbacks) => {
                 let idx;
@@ -47,7 +47,12 @@ export class WatchManager {
         });
     }
 
-    public notifyUpdate(settingName: string, inRoomId: string | null, atLevel: SettingLevel, newValueAtLevel: any) {
+    public notifyUpdate(
+        settingName: string,
+        inRoomId: string | null,
+        atLevel: SettingLevel,
+        newValueAtLevel: any,
+    ): void {
         // Dev note: We could avoid raising changes for ultimately inconsequential changes, but
         // we also don't have a reliable way to get the old value of a setting. Instead, we'll just
         // let it fall through regardless and let the receiver dedupe if they want to.

src/settings/controllers/FontSizeController.ts

@@ -25,7 +25,7 @@ export default class FontSizeController extends SettingController {
         super();
     }
 
-    public onChange(level: SettingLevel, roomId: string, newValue: any) {
+    public onChange(level: SettingLevel, roomId: string, newValue: any): void {
         // Dispatch font size change so that everything open responds to the change.
         dis.dispatch<UpdateFontSizePayload>({
             action: Action.UpdateFontSize,

src/settings/controllers/NotificationControllers.ts

@@ -64,7 +64,7 @@ export class NotificationsEnabledController extends SettingController {
         return calculatedValue;
     }
 
-    public onChange(level: SettingLevel, roomId: string, newValue: any) {
+    public onChange(level: SettingLevel, roomId: string, newValue: any): void {
         if (getNotifier().supportsDesktopNotifications()) {
             getNotifier().setEnabled(newValue);
         }

src/settings/controllers/OrderedMultiController.ts

@@ -44,7 +44,7 @@ export class OrderedMultiController extends SettingController {
         return null; // no override
     }
 
-    public onChange(level: SettingLevel, roomId: string, newValue: any) {
+    public onChange(level: SettingLevel, roomId: string, newValue: any): void {
         for (const controller of this.controllers) {
             controller.onChange(level, roomId, newValue);
         }

src/settings/controllers/PushToMatrixClientController.ts

@@ -26,7 +26,7 @@ export default class PushToMatrixClientController extends SettingController {
         super();
     }
 
-    public onChange(level: SettingLevel, roomId: string, newValue: any) {
+    public onChange(level: SettingLevel, roomId: string, newValue: any): void {
         // XXX does this work? This surely isn't necessarily the effective value,
         // but it's what NotificationsEnabledController does...
         this.setter.call(MatrixClientPeg.get(), this.inverse ? !newValue : newValue);

src/settings/controllers/ReloadOnChangeController.ts

@@ -19,7 +19,7 @@ import PlatformPeg from "../../PlatformPeg";
 import { SettingLevel } from "../SettingLevel";
 
 export default class ReloadOnChangeController extends SettingController {
-    public onChange(level: SettingLevel, roomId: string, newValue: any) {
+    public onChange(level: SettingLevel, roomId: string, newValue: any): void {
         PlatformPeg.get().reload();
     }
 }

src/settings/controllers/SystemFontController.ts

@@ -26,7 +26,7 @@ export default class SystemFontController extends SettingController {
         super();
     }
 
-    public onChange(level: SettingLevel, roomId: string, newValue: any) {
+    public onChange(level: SettingLevel, roomId: string, newValue: any): void {
         // Dispatch font size change so that everything open responds to the change.
         dis.dispatch<UpdateSystemFontPayload>({
             action: Action.UpdateSystemFont,

src/settings/controllers/ThreadBetaController.tsx

@@ -55,7 +55,7 @@ export default class ThreadBetaController extends SettingController {
         return enable;
     }
 
-    public onChange(level: SettingLevel, roomId: string, newValue: any) {
+    public onChange(level: SettingLevel, roomId: string, newValue: any): void {
         // Requires a reload as we change an option flag on the `js-sdk`
         // And the entire sync history needs to be parsed again
         PlatformPeg.get().reload();

src/settings/controllers/UseSystemFontController.ts

@@ -26,7 +26,7 @@ export default class UseSystemFontController extends SettingController {
         super();
     }
 
-    public onChange(level: SettingLevel, roomId: string, newValue: any) {
+    public onChange(level: SettingLevel, roomId: string, newValue: any): void {
         // Dispatch font size change so that everything open responds to the change.
         dis.dispatch<UpdateSystemFontPayload>({
             action: Action.UpdateSystemFont,

src/settings/handlers/AbstractLocalStorageSettingsHandler.ts

@@ -26,7 +26,7 @@ export default abstract class AbstractLocalStorageSettingsHandler extends Settin
     private static objectCache = new Map<string, object>();
     private static storageListenerBound = false;
 
-    private static onStorageEvent = (e: StorageEvent) => {
+    private static onStorageEvent = (e: StorageEvent): void => {
         if (e.key === null) {
             AbstractLocalStorageSettingsHandler.clear();
         } else {
@@ -36,7 +36,7 @@ export default abstract class AbstractLocalStorageSettingsHandler extends Settin
     };
 
     // Expose the clear event for Lifecycle to call, the storage listener only fires for changes from other tabs
-    public static clear() {
+    public static clear(): void {
         AbstractLocalStorageSettingsHandler.itemCache.clear();
         AbstractLocalStorageSettingsHandler.objectCache.clear();
     }

src/settings/handlers/AccountSettingsHandler.ts

@@ -45,12 +45,12 @@ export default class AccountSettingsHandler extends MatrixClientBackedSettingsHa
         return SettingLevel.ACCOUNT;
     }
 
-    public initMatrixClient(oldClient: MatrixClient, newClient: MatrixClient) {
+    public initMatrixClient(oldClient: MatrixClient, newClient: MatrixClient): void {
         oldClient?.removeListener(ClientEvent.AccountData, this.onAccountData);
         newClient.on(ClientEvent.AccountData, this.onAccountData);
     }
 
-    private onAccountData = (event: MatrixEvent, prevEvent: MatrixEvent) => {
+    private onAccountData = (event: MatrixEvent, prevEvent: MatrixEvent): void => {
         if (event.getType() === "org.matrix.preview_urls") {
             let val = event.getContent()["disable"];
             if (typeof val !== "boolean") {
@@ -168,7 +168,7 @@ export default class AccountSettingsHandler extends MatrixClientBackedSettingsHa
         // Attach a deferred *before* setting the account data to ensure we catch any requests
         // which race between different lines.
         const deferred = defer<void>();
-        const handler = (event: MatrixEvent) => {
+        const handler = (event: MatrixEvent): void => {
             if (event.getType() !== eventType || event.getContent()[field] !== value) return;
             this.client.off(ClientEvent.AccountData, handler);
             deferred.resolve();
@@ -229,7 +229,7 @@ export default class AccountSettingsHandler extends MatrixClientBackedSettingsHa
         return objectClone(event.getContent()); // clone to prevent mutation
     }
 
-    private notifyBreadcrumbsUpdate(event: MatrixEvent) {
+    private notifyBreadcrumbsUpdate(event: MatrixEvent): void {
         let val = [];
         if (event.getType() === BREADCRUMBS_LEGACY_EVENT_TYPE) {
             // This seems fishy - try and get the event for the new rooms

src/settings/handlers/DefaultSettingsHandler.ts

@@ -43,7 +43,7 @@ export default class DefaultSettingsHandler extends SettingsHandler {
         throw new Error("Cannot set values on the default level handler");
     }
 
-    public canSetValue(settingName: string, roomId: string) {
+    public canSetValue(settingName: string, roomId: string): boolean {
         return false;
     }
 

src/settings/handlers/DeviceSettingsHandler.ts

@@ -99,11 +99,11 @@ export default class DeviceSettingsHandler extends AbstractLocalStorageSettingsH
         return true; // It's their device, so they should be able to
     }
 
-    public watchSetting(settingName: string, roomId: string, cb: CallbackFn) {
+    public watchSetting(settingName: string, roomId: string, cb: CallbackFn): void {
         this.watchers.watchSetting(settingName, roomId, cb);
     }
 
-    public unwatchSetting(cb: CallbackFn) {
+    public unwatchSetting(cb: CallbackFn): void {
         this.watchers.unwatchSetting(cb);
     }
 
@@ -128,7 +128,7 @@ export default class DeviceSettingsHandler extends AbstractLocalStorageSettingsH
         return this.getBoolean("mx_labs_feature_" + featureName);
     }
 
-    private writeFeature(featureName: string, enabled: boolean | null) {
+    private writeFeature(featureName: string, enabled: boolean | null): void {
         this.setBoolean("mx_labs_feature_" + featureName, enabled);
         this.watchers.notifyUpdate(featureName, null, SettingLevel.DEVICE, enabled);
     }

src/settings/handlers/PlatformSettingsHandler.ts

@@ -35,7 +35,7 @@ export default class PlatformSettingsHandler extends SettingsHandler {
         defaultDispatcher.register(this.onAction);
     }
 
-    private onAction = (payload: ActionPayload) => {
+    private onAction = (payload: ActionPayload): void => {
         if (payload.action === Action.PlatformSet) {
             this.store = {};
             // Load setting values as they are async and `getValue` must be synchronous

src/settings/handlers/RoomAccountSettingsHandler.ts

@@ -36,7 +36,7 @@ export default class RoomAccountSettingsHandler extends MatrixClientBackedSettin
         super();
     }
 
-    protected initMatrixClient(oldClient: MatrixClient, newClient: MatrixClient) {
+    protected initMatrixClient(oldClient: MatrixClient, newClient: MatrixClient): void {
         if (oldClient) {
             oldClient.removeListener(RoomEvent.AccountData, this.onAccountData);
         }
@@ -44,7 +44,7 @@ export default class RoomAccountSettingsHandler extends MatrixClientBackedSettin
         newClient.on(RoomEvent.AccountData, this.onAccountData);
     }
 
-    private onAccountData = (event: MatrixEvent, room: Room, prevEvent: MatrixEvent) => {
+    private onAccountData = (event: MatrixEvent, room: Room, prevEvent: MatrixEvent): void => {
         const roomId = room.roomId;
 
         if (event.getType() === "org.matrix.room.preview_urls") {
@@ -107,7 +107,7 @@ export default class RoomAccountSettingsHandler extends MatrixClientBackedSettin
         await this.client.setRoomAccountData(roomId, eventType, content);
 
         const deferred = defer<void>();
-        const handler = (event: MatrixEvent, room: Room) => {
+        const handler = (event: MatrixEvent, room: Room): void => {
             if (room.roomId !== roomId || event.getType() !== eventType) return;
             if (field !== null && event.getContent()[field] !== value) return;
             this.client.off(RoomEvent.AccountData, handler);

src/settings/handlers/RoomSettingsHandler.ts

@@ -35,7 +35,7 @@ export default class RoomSettingsHandler extends MatrixClientBackedSettingsHandl
         super();
     }
 
-    protected initMatrixClient(oldClient: MatrixClient, newClient: MatrixClient) {
+    protected initMatrixClient(oldClient: MatrixClient, newClient: MatrixClient): void {
         if (oldClient) {
             oldClient.removeListener(RoomStateEvent.Events, this.onEvent);
         }
@@ -43,7 +43,7 @@ export default class RoomSettingsHandler extends MatrixClientBackedSettingsHandl
         newClient.on(RoomStateEvent.Events, this.onEvent);
     }
 
-    private onEvent = (event: MatrixEvent, state: RoomState, prevEvent: MatrixEvent) => {
+    private onEvent = (event: MatrixEvent, state: RoomState, prevEvent: MatrixEvent): void => {
         const roomId = event.getRoomId();
         const room = this.client.getRoom(roomId);
 
@@ -97,7 +97,7 @@ export default class RoomSettingsHandler extends MatrixClientBackedSettingsHandl
         const { event_id: eventId } = await this.client.sendStateEvent(roomId, eventType, content);
 
         const deferred = defer<void>();
-        const handler = (event: MatrixEvent) => {
+        const handler = (event: MatrixEvent): void => {
             if (event.getId() !== eventId) return;
             this.client.off(RoomStateEvent.Events, handler);
             deferred.resolve();

src/settings/watchers/FontWatcher.ts

@@ -36,16 +36,16 @@ export class FontWatcher implements IWatcher {
         this.dispatcherRef = null;
     }
 
-    public start() {
+    public start(): void {
         this.updateFont();
         this.dispatcherRef = dis.register(this.onAction);
     }
 
-    public stop() {
+    public stop(): void {
         dis.unregister(this.dispatcherRef);
     }
 
-    private updateFont() {
+    private updateFont(): void {
         this.setRootFontSize(SettingsStore.getValue("baseFontSize"));
         this.setSystemFont({
             useSystemFont: SettingsStore.getValue("useSystemFont"),
@@ -53,7 +53,7 @@ export class FontWatcher implements IWatcher {
         });
     }
 
-    private onAction = (payload: ActionPayload) => {
+    private onAction = (payload: ActionPayload): void => {
         if (payload.action === Action.UpdateFontSize) {
             this.setRootFontSize(payload.size);
         } else if (payload.action === Action.UpdateSystemFont) {
@@ -71,7 +71,7 @@ export class FontWatcher implements IWatcher {
         }
     };
 
-    private setRootFontSize = (size: number) => {
+    private setRootFontSize = (size: number): void => {
         const fontSize = Math.max(Math.min(FontWatcher.MAX_SIZE, size), FontWatcher.MIN_SIZE);
 
         if (fontSize !== size) {
@@ -80,7 +80,10 @@ export class FontWatcher implements IWatcher {
         document.querySelector<HTMLElement>(":root").style.fontSize = toPx(fontSize);
     };
 
-    private setSystemFont = ({ useSystemFont, font }: Pick<UpdateSystemFontPayload, "useSystemFont" | "font">) => {
+    private setSystemFont = ({
+        useSystemFont,
+        font,
+    }: Pick<UpdateSystemFontPayload, "useSystemFont" | "font">): void => {
         if (useSystemFont) {
             // Make sure that fonts with spaces in their names get interpreted properly
             document.body.style.fontFamily = font

src/settings/watchers/ThemeWatcher.ts

@@ -50,7 +50,7 @@ export default class ThemeWatcher {
         this.currentTheme = this.getEffectiveTheme();
     }
 
-    public start() {
+    public start(): void {
         this.themeWatchRef = SettingsStore.watchSetting("theme", null, this.onChange);
         this.systemThemeWatchRef = SettingsStore.watchSetting("use_system_theme", null, this.onChange);
         if (this.preferDark.addEventListener) {
@@ -61,7 +61,7 @@ export default class ThemeWatcher {
         this.dispatcherRef = dis.register(this.onAction);
     }
 
-    public stop() {
+    public stop(): void {
         if (this.preferDark.addEventListener) {
             this.preferDark.removeEventListener("change", this.onChange);
             this.preferLight.removeEventListener("change", this.onChange);
@@ -72,11 +72,11 @@ export default class ThemeWatcher {
         dis.unregister(this.dispatcherRef);
     }
 
-    private onChange = () => {
+    private onChange = (): void => {
         this.recheck();
     };
 
-    private onAction = (payload: ActionPayload) => {
+    private onAction = (payload: ActionPayload): void => {
         if (payload.action === Action.RecheckTheme) {
             // XXX forceTheme
             this.recheck(payload.forceTheme);
@@ -85,7 +85,7 @@ export default class ThemeWatcher {
 
     // XXX: forceTheme param added here as local echo appears to be unreliable
     // https://github.com/vector-im/element-web/issues/11443
-    public recheck(forceTheme?: string) {
+    public recheck(forceTheme?: string): void {
         const oldTheme = this.currentTheme;
         this.currentTheme = forceTheme === undefined ? this.getEffectiveTheme() : forceTheme;
         if (oldTheme !== this.currentTheme) {
@@ -144,7 +144,7 @@ export default class ThemeWatcher {
         return SettingsStore.getValue("theme");
     }
 
-    private themeBasedOnSystem() {
+    private themeBasedOnSystem(): string {
         let newTheme: string;
         if (this.preferDark.matches) {
             newTheme = "dark";
@@ -160,7 +160,7 @@ export default class ThemeWatcher {
         return newTheme;
     }
 
-    public isSystemThemeSupported() {
+    public isSystemThemeSupported(): boolean {
         return this.preferDark.matches || this.preferLight.matches;
     }
 }