Tech Conference on Web Performance & Scalability

12:30 pm

Cleaning up your giant codebase: Building transpilers and codemods for better code

Sarah Dapul-Weberman - Software Engineer @ Pinterest

Duration: 3 hours

It's easy to make sweeping changes when your codebase is relatively small and you're working with only a few other engineers. But what happens when you grow to have hundreds of engineers, thousands of files, and millions of lines of code? Manual changes are likely to break things and frustrate other people, not to mention, take increasingly large amounts of time.

In this tutorial I will discuss how transpilers and codemods can be used to make large, automated changes to your codebase, useful for cleaning up legacy code or adopting new syntax and best practices. Traditionally, transpilers have translated code between programming languages, but can also be used to make code modifications in a single language. I will show you how transpilers work under the hood, explaining abstract syntax trees and node transformers, and then we will dive into building some codemods. The main part of the tutorial will be helping participants to build code modifications that can be used in their own large codebases. I encourage participants to come with ideas about changes they are interested in making to their own codebases to see if they can be done via codemod or transpiler.