fix(security): add typeof/isArray guards to satisfy CodeQL type-confusion check

Author: fabiovincenzi

src/proxy/processors/pktLineParser.ts

@@ -23,7 +23,7 @@ import { PACKET_SIZE } from './constants';
  * @return {[string[], number]} An array containing the parsed lines and the offset after the last parsed line/flush packet.
  */
 export const parsePacketLines = (buffer: Buffer): [string[], number] => {
-  if (!Buffer.isBuffer(buffer)) {
+  if (typeof buffer === 'string' || Array.isArray(buffer) || !Buffer.isBuffer(buffer)) {
     throw new Error('parsePacketLines expected a Buffer');
   }
   const lines: string[] = [];

src/proxy/processors/push-action/parsePush.ts

@@ -57,7 +57,7 @@ async function exec(req: Request, action: Action): Promise<Action> {
     if (!req.body || req.body.length === 0) {
       throw new Error('No body found in request');
     }
-    if (!Buffer.isBuffer(req.body)) {
+    if (typeof req.body === 'string' || Array.isArray(req.body) || !Buffer.isBuffer(req.body)) {
       throw new Error('Request body must be a Buffer');
     }
     const [packetLines, packDataOffset] = parsePacketLines(req.body);