wtf is vue-codemod?

vue-codemod is a toolkit that automatically rewrites Vue.js code to help teams migrate their apps from Vue 2 to Vue 3. When a framework releases a major new version, the way you write code often changes. Instead of a team of developers manually updating hundreds of files by hand, this tool scans the codebase and applies those changes automatically. At a high level, it works by reading your existing source files, identifying patterns that need updating, and rewriting them in place. For example, if Vue 3 changed how you create a new app instance, the tool finds the old syntax and replaces it with the new one. You run it from the command line, pointing it at a file or folder, and it applies a specific "transformation", a script designed to handle one particular change. The project also includes a browser-based playground where developers can experiment with transformations before running them on a real codebase. This tool is designed for development teams who have existing applications built on Vue 2 and want to upgrade to Vue 3. The migration involves a large number of breaking changes, from how global APIs work to how routing and state management are set up. The README outlines a detailed migration path: developers first use a linter to auto-fix simple issues, then run these codemods for more complex structural changes, then install Vue 3 itself. It's a practical tool for anyone facing a large-scale upgrade who wants to save time and reduce human error. The project is still explicitly marked as experimental, and the README shows a detailed roadmap of what has been built and what is still in progress. Some transformations are fully implemented, while many others are marked as not yet started. The README is also transparent about limitations, it notes that some changes are too nuanced to automate and will always require manual fixes. The tool is built on top of JSCodeshift, a widely used utility for running large-scale code modifications, and is designed to integrate into the broader Vue CLI ecosystem.