js-codemod

Codemod scripts to transform code to next generation JS

Usage no npm install needed!

<script type="module">
  import jsCodemod from 'https://cdn.skypack.dev/js-codemod';
</script>

README

js-codemod

This repository contains a collection of codemod scripts to be used with JSCodeshift.

Setup & Run

  • npm install -g jscodeshift
  • npm install js-codemod
  • jscodeshift <codemod-script> <file>
  • Use the -d option for a dry-run and use -p to print the output for comparison

Included Scripts

use-strict adds a top-level 'use strict' statement to JavaScript files

  • jscodeshift -t node_modules/js-codemod/transforms/use-strict.js <file>

arrow-function transforms functions to arrow functions

  • jscodeshift -t node_modules/js-codemod/transforms/arrow-function.js <file>

It will transform function() { }.bind(this) calls to () => {}. If the only statement in the body is a ReturnStatement it will remove the curly braces. If you are feeling lucky and you know that returning the value of single-expression functions will not affect the behavior of your application you can specify the --inline-single-expressions=true option and it will transform function() { relay(); }.bind(this) to () => relay() instead of () => { relay(); }.

Recast Options

Options to recast's printer can be provided through the printOptions command line argument

  • jscodeshift -t transform.js <file> --printOptions='{"quote":"double"}'