Codemods
Code migration as-a-service
Presenter: OTIS
outline
Backstage
React 17
Shell
Starhome
Module
UI
React 18
const Button = ({ size, color }) => {
return <button style={{ color, fontSize: size }}>Click me</button>;
}
Button.defaultProps = {
size: '16px',
color: 'blue'
}
const Button = ({ size = '16px', color = 'blue' }) => {
return <button style={{ color, fontSize: size }}>Click me</button>;
}
Bot...
Codemod
Let me
What is codemod?
A script used to automate codebase changes, especially during large refactors or migrations
An end-to-end platform for code migrations at scale
BUIld
Codemod learn
Learn from locally changes
2
Scaffold a new codemod package
1. Manually write your own codemod
2. Turn an existing codemod into a Codemod-compatible package.
3
1
Codemod Studio
Online studio
prerequisite
setup
codemod learn
1
Make a change
2
Run `codemod learn`
3
Building the codemod
4
Export/publish the generated codemod
codemod studio
codemod studio
Dependency on git diff
Inconvenient to debug
Poor learning (only 1 example)
Sensitive data can be scanned
codemod STUDIO
1
Add before/after code examples
2
Add natural language descriptions
3
Build codemod with AI
4
Test codemod (and iterate)
5
Exporting codemod
Add before/after code examples
Add natural language descriptions
Build codemod with AI
Can cost money to use AI assistant (PRO version)
Need to describe in detail by writing comments
Can not handle complex cases/ edge cases
Scaffold a new codemod package
1
Verify codemod engine compatibility
2
Initialize codemod package
3
Update transform file content
4
Update package configuration file
5
Publish the codemod
Example
Need knowledge about AST, jscodeshift, codemod scaffold
What is codemod registry
A centralized hub for discovering and sharing Codemods
My
Codemod
user 1
Codemod Registry
user 1
user 2
user 3
Can be shared and reused across projects
Time-saving and free
Change behavior to use AI
Migrating to a new framework or library
Reorganizing a large codebase
Applying new coding standards at scale
Faster migrations and refactoring
Consistency across the codebase
Requires testing to ensure accuracy
Not suitable for minor changes or one-off updates
