From 278c221f1f5eb0cc0d126f43c2406d024817f4e1 Mon Sep 17 00:00:00 2001
From: rmurugan58 <rmurugan@andrew.cmu.edu>
Date: Fri, 25 Apr 2025 22:11:20 -0400
Subject: [PATCH] extracted substr and added check for throwError in Hex.mjs

---
 src/core/lib/Hex.mjs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/core/lib/Hex.mjs b/src/core/lib/Hex.mjs
index 78e1ad58..919d945b 100644
--- a/src/core/lib/Hex.mjs
+++ b/src/core/lib/Hex.mjs
@@ -100,7 +100,7 @@ export function toHexFast(data) {
  * // returns [10,20,30]
  * fromHex("0a:14:1e", "Colon");
  */
-export function fromHex(data, delim="Auto", byteLen=2) {
+export function fromHex(data, delim="Auto", byteLen=2, throwError=false) { //added throwError parameter
     if (byteLen < 1 || Math.round(byteLen) !== byteLen)
         throw new OperationError("Byte length must be a positive integer");
 
@@ -114,7 +114,11 @@ export function fromHex(data, delim="Auto", byteLen=2) {
     const output = [];
     for (let i = 0; i < data.length; i++) {
         for (let j = 0; j < data[i].length; j += byteLen) {
-            output.push(parseInt(data[i].substr(j, byteLen), 16));
+            const chunk = data[i].substr(j, byteLen); //extracted substr into a chunk variable
+            if (throwError && /[^a-f\d]/i.test(chunk)) { //added validation check for when throwError is true
+                throw new OperationError(`Invalid hex character in chunk "${chunk}"`); //throw on invalid hex chunk
+            }
+            output.push(parseInt(chunk, 16)); //parseInt now uses chunk
         }
     }
     return output;