言語切り替えを描画前に実施するよう修正

dictation_client/src/App.tsx

@@ -3,7 +3,7 @@ import { BrowserRouter } from "react-router-dom";
 import { PublicClientApplication } from "@azure/msal-browser";
 import { MsalProvider, useMsal } from "@azure/msal-react";
 import { msalConfig } from "common/msalConfig";
-import { useEffect } from "react";
+import { useEffect, useLayoutEffect } from "react";
 import { useDispatch } from "react-redux";
 import globalAxios, { AxiosError, AxiosResponse } from "axios";
 import { clearToken } from "features/auth";
@@ -35,7 +35,8 @@ const App = (): JSX.Element => {
   }, [dispatch, instance]);
 
   // Language読み取り
-  useEffect(() => {
+  // AADB2Cからのリダイレクト後にレンダリングより先に言語切り替えしたいのでuseLayoutEffectを使う
+  useLayoutEffect(() => {
     const language = document.cookie
       .split(";")
       .map((x) => x.split("="))