As a best-selling author, I invite you to explore my books on Amazon . Don't forget to follow me on Medium and show your support. Thank you! Your support means the world! I remember the first time I tried to change thousands of JavaScript files by hand. I opened each file, found the patterns, and replaced them one by one. It took days. That’s when I discovered AST manipulation – a way to treat code as data and transform it automatically. Let me walk you through eight techniques I use regularly. I’ll keep everything simple, with lots of code you can copy and tweak. Parsing JavaScript into an AST Every transformation starts with parsing. You take a string of code and turn it into a tree structure called an Abstract Syntax Tree (AST). Each node in the tree represents a piece of code – a variable declaration, a function call, a literal value. I use @babel/parser because it supports modern syntax like JSX, TypeScript, and optional chaining.…