Apply strictNullChecks to src/components/auth/* (#10484

* Apply `strictNullChecks` to `src/components/auth/*`

* fix

* strict types

src/components/structures/auth/SetupEncryptionBody.tsx

@@ -39,8 +39,8 @@ interface IProps {
 
 interface IState {
     phase: Phase;
-    verificationRequest: VerificationRequest;
-    backupInfo: IKeyBackupInfo;
+    verificationRequest: VerificationRequest | null;
+    backupInfo: IKeyBackupInfo | null;
     lostKeys: boolean;
 }
 
@@ -96,7 +96,7 @@ export default class SetupEncryptionBody extends React.Component<IProps, IState>
         this.props.onFinished();
         Modal.createDialog(VerificationRequestDialog, {
             verificationRequestPromise: requestPromise,
-            member: cli.getUser(userId),
+            member: cli.getUser(userId) ?? undefined,
             onFinished: async (): Promise<void> => {
                 const request = await requestPromise;
                 request.cancel();
@@ -142,15 +142,16 @@ export default class SetupEncryptionBody extends React.Component<IProps, IState>
     };
 
     public render(): React.ReactNode {
+        const cli = MatrixClientPeg.get();
         const { phase, lostKeys } = this.state;
 
-        if (this.state.verificationRequest) {
+        if (this.state.verificationRequest && cli.getUser(this.state.verificationRequest.otherUserId)) {
             return (
                 <EncryptionPanel
                     layout="dialog"
                     verificationRequest={this.state.verificationRequest}
                     onClose={this.onEncryptionPanelClose}
-                    member={MatrixClientPeg.get().getUser(this.state.verificationRequest.otherUserId)}
+                    member={cli.getUser(this.state.verificationRequest.otherUserId)!}
                     isRoomEncrypted={false}
                 />
             );