Make more of the codebase conform to strict types (#10857)

src/components/structures/FilePanel.tsx

@@ -56,7 +56,7 @@ class FilePanel extends React.Component<IProps, IState> {
     // This is used to track if a decrypted event was a live event and should be
     // added to the timeline.
     private decryptingEvents = new Set<string>();
-    public noRoom: boolean;
+    public noRoom = false;
     private card = createRef<HTMLDivElement>();
 
     public state: IState = {

src/components/structures/GenericDropdownMenu.tsx

@@ -125,7 +125,7 @@ export function GenericDropdownMenu<T>({
 }: IProps<T>): JSX.Element {
     const [menuDisplayed, button, openMenu, closeMenu] = useContextMenu<HTMLElement>();
 
-    const selected: GenericDropdownMenuItem<T> | null = options
+    const selected: GenericDropdownMenuItem<T> | undefined = options
         .flatMap((it) => (isGenericDropdownMenuGroup(it) ? [it, ...it.options] : [it]))
         .find((option) => (toKey ? toKey(option.key) === toKey(value) : option.key === value));
     let contextMenuOptions: JSX.Element;

src/components/structures/ScrollPanel.tsx

@@ -181,19 +181,19 @@ export default class ScrollPanel extends React.Component<IProps> {
     private unmounted = false;
     private scrollTimeout?: Timer;
     // Are we currently trying to backfill?
-    private isFilling: boolean;
+    private isFilling = false;
     // Is the current fill request caused by a props update?
     private isFillingDueToPropsUpdate = false;
     // Did another request to check the fill state arrive while we were trying to backfill?
-    private fillRequestWhileRunning: boolean;
+    private fillRequestWhileRunning = false;
     // Is that next fill request scheduled because of a props update?
-    private pendingFillDueToPropsUpdate: boolean;
-    private scrollState: IScrollState;
+    private pendingFillDueToPropsUpdate = false;
+    private scrollState!: IScrollState;
     private preventShrinkingState: IPreventShrinkingState | null = null;
     private unfillDebouncer: number | null = null;
-    private bottomGrowth: number;
-    private minListHeight: number;
-    private heightUpdateInProgress: boolean;
+    private bottomGrowth!: number;
+    private minListHeight!: number;
+    private heightUpdateInProgress = false;
     private divScroll: HTMLDivElement | null = null;
 
     public constructor(props: IProps) {

src/components/structures/auth/CompleteSecurity.tsx

@@ -28,7 +28,7 @@ interface IProps {
 }
 
 interface IState {
-    phase: Phase;
+    phase?: Phase;
     lostKeys: boolean;
 }
 

src/components/structures/auth/Login.tsx

@@ -19,7 +19,7 @@ import classNames from "classnames";
 import { logger } from "matrix-js-sdk/src/logger";
 import { ISSOFlow, LoginFlow, SSOAction } from "matrix-js-sdk/src/@types/auth";
 
-import { _t, _td } from "../../../languageHandler";
+import { _t, _td, UserFriendlyError } from "../../../languageHandler";
 import Login from "../../../Login";
 import { messageForConnectionError, messageForLoginError } from "../../../utils/ErrorUtils";
 import AutoDiscoveryUtils from "../../../utils/AutoDiscoveryUtils";
@@ -110,7 +110,7 @@ type OnPasswordLogin = {
  */
 export default class LoginComponent extends React.PureComponent<IProps, IState> {
     private unmounted = false;
-    private loginLogic: Login;
+    private loginLogic!: Login;
 
     private readonly stepRendererMap: Record<string, () => ReactNode>;
 
@@ -265,7 +265,7 @@ export default class LoginComponent extends React.PureComponent<IProps, IState>
                 logger.error("Problem parsing URL or unhandled error doing .well-known discovery:", e);
 
                 let message = _t("Failed to perform homeserver discovery");
-                if (e.translatedMessage) {
+                if (e instanceof UserFriendlyError && e.translatedMessage) {
                     message = e.translatedMessage;
                 }
 

src/components/structures/auth/SetupEncryptionBody.tsx

@@ -38,7 +38,7 @@ interface IProps {
 }
 
 interface IState {
-    phase: Phase;
+    phase?: Phase;
     verificationRequest: VerificationRequest | null;
     backupInfo: IKeyBackupInfo | null;
     lostKeys: boolean;

src/components/structures/auth/SoftLogout.tsx

@@ -18,6 +18,7 @@ import React, { ChangeEvent, SyntheticEvent } from "react";
 import { logger } from "matrix-js-sdk/src/logger";
 import { Optional } from "matrix-events-sdk";
 import { ISSOFlow, LoginFlow, SSOAction } from "matrix-js-sdk/src/@types/auth";
+import { MatrixError } from "matrix-js-sdk/src/http-api";
 
 import { _t } from "../../../languageHandler";
 import dis from "../../../dispatcher/dispatcher";
@@ -164,7 +165,11 @@ export default class SoftLogout extends React.Component<IProps, IState> {
             credentials = await sendLoginRequest(hsUrl, isUrl, loginType, loginParams);
         } catch (e) {
             let errorText = _t("Failed to re-authenticate due to a homeserver problem");
-            if (e.errcode === "M_FORBIDDEN" && (e.httpStatus === 401 || e.httpStatus === 403)) {
+            if (
+                e instanceof MatrixError &&
+                e.errcode === "M_FORBIDDEN" &&
+                (e.httpStatus === 401 || e.httpStatus === 403)
+            ) {
                 errorText = _t("Incorrect password");
             }