properly parse request body using express.json()

lib/DataTransmitServer.js

@@ -1,5 +1,6 @@
 import express from "express";
 const app = express()
+app.use(express.json()) // for parsing application/json
 const port = 80
 
 import { promises as fs } from 'fs';
@@ -16,10 +17,20 @@ async function writeServerStats() {
 
 async function initalize() {
     app.post("/", async (req, res) => {
-        console.log(req.body);
-        if (typeof req.body.PacketName !== 'string') {
-            return res.sendStatus(400); // https://http.cat/400
+        if (req.body === undefined) {
+            console.log("req.body is undefined");
+            return res.sendStatus(400);
         }
+        if (req.body.PacketName === undefined) {
+            console.log("req.body.PacketName is undefined");
+            return res.sendStatus(400);
+        }
+        if (typeof req.body.PacketName !== "string") {
+            console.log("req.body.PacketName is not a string");
+            return res.sendStatus(400);
+        }
+
+        console.log("Received packet: " + req.body.PacketName);
 
         const body = req.body;