Code commenter to make you feel bad about your code
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.gitignore Replace all instances of pettier with new name Jan 22, 2019


Code commenter to make you feel bad about your code.


petty-af was inspired by prettier, the popular code formatting tool.

The similarities end there. It does not modify your code and only adds comments. The comments are not helpful hints but are passive aggressive judgements about your coding style.


In your repo:

npm install petty-af


yarn add petty-af

Or you could globally install it (but why would you??):

npm install -g petty-af



./node_modules/.bin/petty-af [files]


petty-af [files]


Yeah there's only one option. Hey this is an opinionated formatter. You knew what you were getting into. The option is


This writes out results into a new file (*.js becomes *.pettified.js) instead of ruining your current one.

What Does It Do?

It only does 2 things right now, complain about callback depth and function length. But I'm planning to add more.


The core inspiration for this project is "Wouldn't it be funny if you removed a letter from prettier, thus spelling pettier? What would a tool like that do?" The exact name is unfortunately not available as such but the spirit remains.

The more useful takeaway is it's a fun way to demo that you can do a lot using existing tools that work with ASTs (Abstract Syntax Trees). The main tools doing the heavy lifting here are @babel/parser and @babel/traverse.

  • @babel/parser parses the code and creates the AST.
  • @babel/traverse traverses the AST for you so you don't have to remember how to do recursion.

The plan is to write some blog posts explaining how anyone can do this.


Yeah go for it. I don't really know how open source works but I'm sure we can figure it out.