yungsters / js-codemod

Codemod scripts to transform code to next generation JS

js-codemod

This repository contains a collection of codemod scripts for use with JSCodeshift.

Setup & Run

• npm install -g jscodeshift
• git clone https://github.com/cpojer/js-codemod.git
• jscodeshift -t <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 js-codemod/transforms/use-strict.js <file>

arrow-function transforms functions to arrow functions

• jscodeshift -t 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(); }.

object-shorthand transforms object literals to use ES6 shorthand for properties and methods.

• jscodeshift -t js-codemod/transforms/object-shorthand.js <file>

unquote-properties removes quotes from object properties whose keys are strings which are valid identifiers.

• jscodeshift -t js-codemod/transforms/unquote-properties.js <file>

Included extensions

jscodeshift-imports helpers for modifying import and require statements, see docs.

Recast Options

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

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