optimistic ui for message sending and submit state

src/utils/fetchers.js

@@ -0,0 +1,18 @@
+import axios from 'axios';
+import useSWR from 'swr';
+import useSWRMutation from 'swr/mutation';
+
+const fetcher = (url) => fetch(url).then((res) => res.json());
+
+const postRequest = async (url, { arg }) => {
+  return await axios.post(url, { arg });
+};
+
+export const swr = (path) => useSWR(path, fetcher);
+
+export default function manualSWR(path, type, successCallback) {
+  const fetchFunction = type === 'get' ? fetcher : postRequest;
+  return useSWRMutation(path, fetchFunction, {
+    onSuccess: successCallback
+  });
+};