Manage large refactors with JSCodeShift

on YouTube ↗25m

" summary

Shows how to automate a large refactor from an in-house Phoenix component library to Adobe Spectrum across hundreds of repositories and thousands of files using JSCodeShift with a TypeScript parser. Demonstrates codemods that rewrite JSX, remap props, and update imports, with unit tests validating before/after pairs. AI accelerates authoring: ChatGPT 3.5 generates working transforms that handle most cases but mis-merges imports and needs small manual fixes; GPT-4 reduces errors. The workflow runs transforms at scale and iterates quickly by prompting the model.

AI-written summary · about

" chapters (5)

1. 0:00The need for code mods
2. 2:23Understanding ASTs
3. 6:51JS Codemod tools
4. 10:41Automating with AI
5. 22:45The future of refactoring

" related talks

• 40mRefactoring large JavaScript codebasesMichele Riva · jsday 2022
• 47mComputer, refactor my code!Zbyszek Tenerowicz · GrillJS 2019
• 21mAutomating Front-End RefactoringAhmed El Gabri · AmsterdamJS Conference 2017
• 34mCodemods in the Era of AIMaja Wichrowska · Nordic.js 2025
• 20mThey see me refactorin'. They hatin'Vit Gottwald · ReactiveConf 2018
• 40mHow To (Semi-)Automate JavaScript RefactoringGiles Bowkett · Fluent 2013
• 43mMachine Powered Refactoring: Leverage AST's to Push Your Legacy Code (& the Web) ForwardAmal Hussein · Node+JS Interactive 2018
• 29mLarge Scale Migrations Using Recast and jscodeshift to ScaleFrancois Ward · React Boston 2018