fix: add more explicit return types (#49567)

api/middleware/index.ts

@@ -5,7 +5,7 @@ export async function auth0Verify(
   this: FastifyInstance,
   request: FastifyRequest,
   reply: FastifyReply
-) {
+): Promise<void> {
   await this.authenticate(request, reply);
 }
 
@@ -16,7 +16,7 @@ export function testMiddleware(
   req: MiddieRequest,
   res: MiddieResponse,
   next: NextFunction
-) {
+): void {
   console.log('Test middleware running');
   console.log(req.headers);
   console.log(req.query);

api/utils/index.ts

@@ -1,6 +1,6 @@
 import { randomBytes, createHash } from 'crypto';
 
-export function base64URLEncode(buf: Buffer) {
+export function base64URLEncode(buf: Buffer): string {
   return buf
     .toString('base64')
     .replace(/\+/g, '-')

client/src/components/Header/index.tsx

@@ -72,7 +72,7 @@ export class Header extends React.Component<
   }
 
   // elementToFocus must be a link in the language menu
-  showLanguageMenu(elementToFocus: HTMLButtonElement | null) {
+  showLanguageMenu(elementToFocus: HTMLButtonElement | null): void {
     this.setState({ isLanguageMenuDisplayed: true }, () =>
       elementToFocus?.focus()
     );