style-sync

Detect and fix style inconsistencies across your JavaScript/TypeScript codebase — automatically.

Ever noticed some files use semicolons and some don't? Some have trailing commas and some don't? style-sync scans your entire project, figures out your dominant style, and fixes every file to match — in one command.

Usage

No install needed. Just run inside any JS/TS project:

npx style-sync

What happens

1. Scans all .js, .ts, .jsx, .tsx files (ignores node_modules, dist, build)
2. Reports your current style breakdown
3. Asks you to choose if a style is ambiguous (close to 50/50)
4. Fixes every file using Prettier under the hood

Example output

style-sync — fixing your codebase style inconsistencies

Scanning /your/project...

Files scanned:     24
Semicolons:        58 with · 12 without · dominant: always
Trailing commas:   10 with · 22 without · dominant: ambiguous

⚠  Trailing commas are ambiguous. Which style do you want?
❯  Always use trailing commas
   Never use trailing commas

Apply these fixes to 24 files? › Yes

Fixing...

✔ Fixed:   18 files
  Skipped: 6 files (already correct)

Done! Your codebase is now consistent.

What it fixes (v1)

| Rule | Description | |------|-------------| | semi | Enforce or remove semicolons consistently | | trailingComma | Enforce or remove trailing commas in objects, arrays, and function params |

More rules coming in v2 (quotes, bracket spacing, arrow function parens).

How it works

• Uses @babel/parser to parse your code into an AST — so it never mistakes a semicolon inside a string for a real one
• Uses Prettier's Node.js API to do the actual formatting — battle-tested, no reinventing the wheel
• Respects any existing .prettierrc config you have, overriding only the rules it manages

Requirements

• Node.js 16+
• Works with JavaScript and TypeScript projects

License

MIT