Refact/project (#189)

* refactor: cleanup project entry point
* refactor: remove unused
* refactor: folder restructure

client/src/common/hooks/useMutateEvents.js

@@ -0,0 +1,37 @@
+import { useMutation, useQueryClient } from 'react-query';
+
+import { EVENTS_TABLE } from '../api/apiConstants';
+
+/**
+ * @description utility hook to handle mutations in events
+ * @param mutation
+ */
+export default function useMutateEvents(mutation){
+  const queryClient = useQueryClient();
+  return useMutation(mutation, {
+    onMutate: async (newEvent) => {
+      // cancel ongoing queries
+      queryClient.cancelQueries(EVENTS_TABLE, { exact: true });
+
+      // Snapshot the previous value
+      const previousEvent = queryClient.getQueryData([EVENTS_TABLE, newEvent.id]);
+
+      // optimistically update object
+      queryClient.setQueryData([EVENTS_TABLE, newEvent.id], newEvent);
+
+      // Return a context with the previous and new event
+      return { previousEvent, newEvent };
+    },
+
+    // Mutation fails, rollback undoes optimist update
+    onError: (error, newEvent, context) => {
+      queryClient.setQueryData([EVENTS_TABLE, context.newEvent.id], context.previousEvent);
+    },
+
+    // Mutation finished, failed or successful
+    // Fetch anyway, just to be sure
+    onSettled: (newEvent) => {
+      queryClient.invalidateQueries([EVENTS_TABLE, newEvent.id]);
+    },
+  });
+}