♻️(frontend) tiny cleanup of the room regex related stuff

since this is used for the routing *and* for common validation, split a
few things

src/frontend/src/App.tsx

@@ -7,7 +7,7 @@ import { useTranslation } from 'react-i18next'
 import { useLang } from 'hoofd'
 import { Route, Switch } from 'wouter'
 import { HomeRoute } from '@/features/home'
-import { RoomRoute, roomIdRegex } from '@/features/rooms'
+import { RoomRoute, roomRouteRegex } from '@/features/rooms'
 import { NotFound } from './routes/NotFound'
 import './i18n/init'
 import { RenderIfUserFetched } from './features/auth'
@@ -23,7 +23,7 @@ function App() {
         <RenderIfUserFetched>
           <Switch>
             <Route path="/" component={HomeRoute} />
-            <Route path={roomIdRegex} component={RoomRoute} />
+            <Route path={roomRouteRegex} component={RoomRoute} />
             <Route component={NotFound} />
           </Switch>
         </RenderIfUserFetched>

src/frontend/src/features/rooms/index.ts

@@ -1,3 +1,3 @@
 export { navigateToNewRoom } from './navigation/navigateToNewRoom'
 export { Room as RoomRoute } from './routes/Room'
-export { roomIdRegex } from './utils/generateRoomId'
+export { roomRouteRegex, isRoomValid } from './utils/isRoomValid'

src/frontend/src/features/rooms/utils/generateRoomId.ts

@@ -12,5 +12,3 @@ const generateSegment = (length: number): string =>
 // Generates a unique room identifier following the Google Meet format
 export const generateRoomId = () =>
   [generateSegment(3), generateSegment(4), generateSegment(3)].join('-')
-
-export const roomIdRegex = /^[/](?<roomId>[a-z]{3}-[a-z]{4}-[a-z]{3})$/

src/frontend/src/features/rooms/utils/isRoomValid.ts

@@ -0,0 +1,5 @@
+const roomIdPattern = '[a-z]{3}-[a-z]{4}-[a-z]{3}'
+export const roomRouteRegex = new RegExp(`^[/](?<roomId>${roomIdPattern})$`)
+
+export const isRoomValid = (roomId: string) =>
+  new RegExp(`^${roomIdPattern}$`).test(roomId)