アイヌ語追加 (#428) (#433)

Reviewed-on: #433
Co-authored-by: miteruzo <miteruzo@naver.com>

frontend/src/components/ErrorScreen.test.tsx

@@ -1,5 +1,6 @@
 import { render, screen } from '@testing-library/react'
 import { HelmetProvider } from 'react-helmet-async'
+import { MemoryRouter } from 'react-router-dom'
 import { describe, expect, it } from 'vitest'
 
 import ErrorScreen from '@/components/ErrorScreen'
@@ -12,9 +13,9 @@ describe ('ErrorScreen', () => {
     [503, '鯖死んでるよ（泣）'],
   ]) ('renders status %s', (status, message) => {
     render (
-        <HelmetProvider>
+        <MemoryRouter><HelmetProvider>
           <ErrorScreen status={status}/>
-        </HelmetProvider>,
+        </HelmetProvider></MemoryRouter>,
     )
 
     expect (screen.getByText (String (status))).toBeInTheDocument ()
@@ -24,9 +25,9 @@ describe ('ErrorScreen', () => {
 
   it ('throws for unsupported statuses', () => {
     expect (() => render (
-        <HelmetProvider>
+        <MemoryRouter><HelmetProvider>
           <ErrorScreen status={418}/>
-        </HelmetProvider>,
+        </HelmetProvider></MemoryRouter>,
     )).toThrow ()
   })
 })