Pass in a string, get a buffer back. Pass in a buffer, get the same buffer back.
npm install to-buffer
var toBuffer = require('to-buffer');
console.log(toBuffer('hi')); // <Buffer 68 69>
console.log(toBuffer(Buffer('hi'))); // <Buffer 68 69>
console.log(toBuffer('6869', 'hex')); // <Buffer 68 69>
console.log(toBuffer(43)); // throws
MIT