Conform more of the codebase to strictNullChecks (#11100)

src/HtmlUtils.tsx

@@ -466,7 +466,7 @@ const emojiToJsxSpan = (emoji: string, key: number): JSX.Element => (
  */
 export function formatEmojis(message: string | undefined, isHtmlMessage?: false): JSX.Element[];
 export function formatEmojis(message: string | undefined, isHtmlMessage: true): string[];
-export function formatEmojis(message: string | undefined, isHtmlMessage: boolean): (JSX.Element | string)[] {
+export function formatEmojis(message: string | undefined, isHtmlMessage?: boolean): (JSX.Element | string)[] {
     const emojiToSpan = isHtmlMessage ? emojiToHtmlSpan : emojiToJsxSpan;
     const result: (JSX.Element | string)[] = [];
     if (!message) return result;

src/ScalarMessaging.ts

@@ -626,7 +626,7 @@ async function setBotPower(
             success: true,
         });
     } catch (err) {
-        sendError(event, err.message ? err.message : _t("Failed to send request."), err);
+        sendError(event, err instanceof Error ? err.message : _t("Failed to send request."), err);
     }
 }
 

src/async-components/views/dialogs/security/CreateKeyBackupDialog.tsx

@@ -42,7 +42,7 @@ interface IState {
     passPhraseConfirm: string;
     copied: boolean;
     downloaded: boolean;
-    error?: string;
+    error?: boolean;
 }
 
 /*
@@ -94,7 +94,7 @@ export default class CreateKeyBackupDialog extends React.PureComponent<IProps, I
                 cli.deleteKeyBackupVersion(info.version);
             }
             this.setState({
-                error: e,
+                error: true,
             });
         }
     };

src/components/structures/RoomView.tsx

@@ -220,7 +220,6 @@ export interface IRoomState {
     showUrlPreview?: boolean;
     e2eStatus?: E2EStatus;
     rejecting?: boolean;
-    rejectError?: Error;
     hasPinnedWidgets?: boolean;
     mainSplitContentType?: MainSplitContentType;
     // whether or not a spaces context switch brought us here,
@@ -1680,7 +1679,6 @@ export class RoomView extends React.Component<IRoomProps, IRoomState> {
 
                 this.setState({
                     rejecting: false,
-                    rejectError: error,
                 });
             },
         );
@@ -1714,7 +1712,6 @@ export class RoomView extends React.Component<IRoomProps, IRoomState> {
 
             this.setState({
                 rejecting: false,
-                rejectError: error,
             });
         }
     };

src/components/structures/ScrollPanel.tsx

@@ -491,7 +491,7 @@ export default class ScrollPanel extends React.Component<IProps> {
         // This would cause jumping to happen on Chrome/macOS.
         return new Promise((resolve) => window.setTimeout(resolve, 1))
             .then(() => {
-                return this.props.onFillRequest(backwards);
+                return this.props.onFillRequest?.(backwards);
             })
             .finally(() => {
                 this.pendingFillRequests[dir] = false;

src/components/structures/TimelinePanel.tsx

@@ -1623,12 +1623,12 @@ class TimelinePanel extends React.Component<IProps, IState> {
             // dialog, let's jump to the end of the timeline. If we weren't,
             // something has gone badly wrong and rather than causing a loop of
             // undismissable dialogs, let's just give up.
-            if (eventId) {
+            if (eventId && this.props.timelineSet.room) {
                 onFinished = () => {
                     // go via the dispatcher so that the URL is updated
                     dis.dispatch<ViewRoomPayload>({
                         action: Action.ViewRoom,
-                        room_id: this.props.timelineSet.room.roomId,
+                        room_id: this.props.timelineSet.room!.roomId,
                         metricsTrigger: undefined, // room doesn't change
                     });
                 };
@@ -2098,7 +2098,7 @@ class TimelinePanel extends React.Component<IProps, IState> {
         // forwards, otherwise if somebody hits the bottom of the loaded
         // events when viewing historical messages, we get stuck in a loop
         // of paginating our way through the entire history of the room.
-        const stickyBottom = !this.timelineWindow.canPaginate(EventTimeline.FORWARDS);
+        const stickyBottom = !this.timelineWindow?.canPaginate(EventTimeline.FORWARDS);
 
         // If the state is PREPARED or CATCHUP, we're still waiting for the js-sdk to sync with
         // the HS and fetch the latest events, so we are effectively forward paginating.

src/components/structures/UserView.tsx

@@ -75,7 +75,7 @@ export default class UserView extends React.Component<IProps, IState> {
         } catch (err) {
             Modal.createDialog(ErrorDialog, {
                 title: _t("Could not load user profile"),
-                description: err && err.message ? err.message : _t("Operation failed"),
+                description: err instanceof Error ? err.message : _t("Operation failed"),
             });
             this.setState({ loading: false });
             return;

src/components/views/context_menus/WidgetContextMenu.tsx

@@ -71,7 +71,7 @@ export const WidgetContextMenu: React.FC<IProps> = ({
             } catch (err) {
                 logger.error("Failed to start livestream", err);
                 // XXX: won't i18n well, but looks like widget api only support 'message'?
-                const message = err.message || _t("Unable to start audio streaming.");
+                const message = err instanceof Error ? err.message : _t("Unable to start audio streaming.");
                 Modal.createDialog(ErrorDialog, {
                     title: _t("Failed to start livestream"),
                     description: message,

src/components/views/dialogs/BugReportDialog.tsx

@@ -160,7 +160,7 @@ export default class BugReportDialog extends React.Component<IProps, IState> {
             if (!this.unmounted) {
                 this.setState({
                     downloadBusy: false,
-                    downloadProgress: _t("Failed to send logs: ") + `${err.message}`,
+                    downloadProgress: _t("Failed to send logs: ") + `${err instanceof Error ? err.message : ""}`,
                 });
             }
         }

src/components/views/dialogs/ConfirmAndWaitRedactDialog.tsx

@@ -16,6 +16,7 @@ limitations under the License.
 
 import React from "react";
 import { MatrixEvent } from "matrix-js-sdk/src/models/event";
+import { HTTPError, MatrixError } from "matrix-js-sdk/src/matrix";
 
 import { _t } from "../../../languageHandler";
 import ConfirmRedactDialog from "./ConfirmRedactDialog";
@@ -62,7 +63,13 @@ export default class ConfirmAndWaitRedactDialog extends React.PureComponent<IPro
                 await this.props.redact();
                 this.props.onFinished(true);
             } catch (error) {
-                const code = error.errcode || error.statusCode;
+                let code: string | number | undefined;
+                if (error instanceof MatrixError) {
+                    code = error.errcode;
+                } else if (error instanceof HTTPError) {
+                    code = error.httpStatus;
+                }
+
                 if (typeof code !== "undefined") {
                     this.setState({ redactionErrorCode: code });
                 } else {

src/components/views/messages/MKeyVerificationRequest.tsx

@@ -75,7 +75,7 @@ export default class MKeyVerificationRequest extends React.Component<IProps> {
                 this.openRequest();
                 await request.accept();
             } catch (err) {
-                logger.error(err.message);
+                logger.error(err);
             }
         }
     };
@@ -86,7 +86,7 @@ export default class MKeyVerificationRequest extends React.Component<IProps> {
             try {
                 await request.cancel();
             } catch (err) {
-                logger.error(err.message);
+                logger.error(err);
             }
         }
     };

src/components/views/room_settings/UrlPreviewSettings.tsx

@@ -28,14 +28,14 @@ import { Action } from "../../../dispatcher/actions";
 import { SettingLevel } from "../../../settings/SettingLevel";
 import SettingsFlag from "../elements/SettingsFlag";
 import SettingsFieldset from "../settings/SettingsFieldset";
-import AccessibleButton from "../elements/AccessibleButton";
+import AccessibleButton, { ButtonEvent } from "../elements/AccessibleButton";
 
 interface IProps {
     room: Room;
 }
 
 export default class UrlPreviewSettings extends React.Component<IProps> {
-    private onClickUserSettings = (e: React.MouseEvent): void => {
+    private onClickUserSettings = (e: ButtonEvent): void => {
         e.preventDefault();
         e.stopPropagation();
         dis.fire(Action.ViewUserSettings);

src/components/views/rooms/BasicMessageComposer.tsx

@@ -132,7 +132,7 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
     private hasTextSelected = false;
 
     private _isCaretAtEnd = false;
-    private lastCaret: DocumentOffset;
+    private lastCaret!: DocumentOffset;
     private lastSelection: ReturnType<typeof cloneSelection> | null = null;
 
     private readonly useMarkdownHandle: string;

src/components/views/settings/ProfileSettings.tsx

@@ -124,7 +124,7 @@ export default class ProfileSettings extends React.Component<{}, IState> {
             logger.log("Failed to save profile", err);
             Modal.createDialog(ErrorDialog, {
                 title: _t("Failed to save your profile"),
-                description: err && err.message ? err.message : _t("The operation could not be completed"),
+                description: err instanceof Error ? err.message : _t("The operation could not be completed"),
             });
         }
 

test/settings/handlers/DeviceSettingsHandler-test.ts

@@ -66,7 +66,7 @@ describe("DeviceSettingsHandler", () => {
 
         afterEach(() => {
             MatrixClientPeg.get = () => null;
-            MatrixClientPeg.safeGet = () => null;
+            MatrixClientPeg.safeGet = () => new MatrixClient({ baseUrl: "foobar" });
         });
 
         it("Returns the value for a disabled feature", () => {

test/stores/room-list/MessagePreviewStore-test.ts

@@ -208,8 +208,8 @@ describe("MessagePreviewStore", () => {
 
         const preview = await store.getPreviewForRoom(room, DefaultTagID.Untagged);
         expect(preview).toBeDefined();
-        expect(preview.isThreadReply).toBe(false);
+        expect(preview?.isThreadReply).toBe(false);
-        expect(preview.text).toMatchInlineSnapshot(`"@sender:server reacted 🙃 to First message"`);
+        expect(preview?.text).toMatchInlineSnapshot(`"@sender:server reacted 🙃 to First message"`);
     });
 
     it("should generate the correct preview for a reaction on a thread root", async () => {
@@ -227,7 +227,7 @@ describe("MessagePreviewStore", () => {
 
         const preview = await store.getPreviewForRoom(room, DefaultTagID.Untagged);
         expect(preview).toBeDefined();
-        expect(preview.isThreadReply).toBe(false);
+        expect(preview?.isThreadReply).toBe(false);
-        expect(preview.text).toContain("You reacted 🙃 to root event message");
+        expect(preview?.text).toContain("You reacted 🙃 to root event message");
     });
 });