never make two app div

packages/backend/src/server/web/boot.js

@@ -13,6 +13,7 @@
 
 // ブロックの中に入れないと、定義した変数がブラウザのグローバルスコープに登録されてしまい邪魔なので
 (async () => {
+	console.log('boot!')
 	window.onerror = (e) => {
 		renderError('SOMETHING_HAPPENED', e.toString());
 	};
@@ -58,14 +59,11 @@
 		? `?salt=${localStorage.getItem('salt')}`
 		: '';
 
-	const script = document.createElement('script');
-	script.setAttribute('src', `/assets/${CLIENT_ENTRY}${salt}`);
-	script.setAttribute('type', 'module');
-	script.addEventListener('error', async () => {
-		await checkUpdate();
-		renderError('APP_FETCH_FAILED');
-	});
-	document.head.appendChild(script);
+	import(`/assets/${CLIENT_ENTRY}${salt}`)
+		.catch(async () => {
+			await checkUpdate();
+			renderError('APP_FETCH_FAILED');
+		})
 	//#endregion
 
 	//#region Theme

packages/client/src/init.ts

@@ -203,8 +203,19 @@ if (splash) splash.addEventListener('transitionend', () => {
 	splash.remove();
 });
 
-const rootEl = document.createElement('div');
-document.body.appendChild(rootEl);
+const rootEl = (() => {
+	const MISSKEY_MOUNT_DIV_ID = 'misskey_app';
+
+	const currentEl = document.getElementById(MISSKEY_MOUNT_DIV_ID);
+
+	if (currentEl) return currentEl;
+
+	const rootEl = document.createElement('div');
+	rootEl.id = MISSKEY_MOUNT_DIV_ID;
+	document.body.appendChild(rootEl);
+	return rootEl;
+})()
+
 app.mount(rootEl);
 
 // boot.jsのやつを解除