scmin removes unnecessary semicolons from JavaScript.

scmax adds unnecessary semicolons to JavaScript.

Based on the Esprima JavaScript parser (esprima.org).

npm install -g scmin

scmin unnecessary-semicolons.js > lovely.js

scmax not-enough-semicolons.js > bloated.js

scmin i-like-pipes.js | scmax > why-not.js

JavaScript's automatic semicolon insertion allows you to omit semicolons in certain situations.

scmin removes semicolons that are unnecessary due to automatic semicolon insertion.

scmax adds explicit semicolons so that automatic semicolon insertion is never used.

Both of them preserve whitespace; only semicolons are added or removed.