How It Works

The conversion happens in three phases. After each phase, the changes are committed to Git automatically.

Phase 1: Rename files (with temp suffix)

All files and directories are renamed to the target casing. However, on case-insensitive filesystems like macOS, renaming Common to common directly would fail because they are considered the same path.

To work around this, any segment where only the casing changes gets a temporary __tmp suffix:

components/Common/View.tsx → components/common__tmp/view__tmp.tsx

Files that already have the correct casing are left untouched.

Phase 2: Remove temp suffixes

All __tmp suffixes are stripped from files and directories:

components/common__tmp/view__tmp.tsx → components/common/view.tsx

This two-phase rename strategy ensures the conversion works reliably on both case-sensitive and case-insensitive filesystems.

Phase 3: Update code imports

A jscodeshift codemod runs over all code files (.ts, .tsx, .js, .jsx, .mjs, .cjs) and transforms import/export paths in the AST.

Only paths that start with a recognized prefix are transformed. External package imports like react or lodash are left unchanged.

See Supported Transforms for the full list of statement types that are handled.

Preserved files

Certain files are intentionally left unchanged:

• Underscore-prefixed files like _app.tsx and _document.tsx (Next.js conventions)
• All-uppercase files like README.md, LICENSE, and CHANGELOG
• Bracketed route parameters like [id].tsx and [...slug].tsx (Next.js dynamic routes)

Casing functions

kebab-case inserts hyphens at camelCase boundaries and converts underscores and spaces to hyphens:

MyComponent   → my-component
camelCase     → camel-case
XMLParser     → xmlparser

snake_case inserts underscores at camelCase boundaries and converts hyphens and spaces to underscores:

MyComponent   → my_component
camelCase     → camel_case
XMLParser     → xmlparser