Send back only new files on upload.

util/generateUniqueFilename.ts

@@ -1,7 +1,16 @@
 import path from "path";
 
 export default function (file: Express.Multer.File) {
-  return `${file.originalname}-${Math.floor(Date.now() / 1000)}${path.extname(
+  return `${path.parse(path.basename(file.originalname)).name}-${Math.floor(
+    Date.now() / 1000
+  )}${path.extname(file.originalname)}`;
+}
+
+export function generateUniqueBillFilename(
+  file: Express.Multer.File,
+  invoice_number: string
+) {
+  return `${invoice_number}-${Math.floor(Date.now() / 1000)}${path.extname(
     file.originalname
   )}`;
 }