JavaScript Essentials for Beginning Pentesters

This guide explains how to inspect, format, search, and debug JavaScript in browser developer tools and how to use Burp Suite (Match & Replace, scope controls) to modify proxied script responses—demonstrating steps to locate source maps, pretty-print minified code, set breakpoints, extract strings or endpoints, and alter client-side values (e.g., changing 'index' to 'admin') while advising that server-side validation is required to prevent client-side bypasses.