how to decode base64 with buffer in js code example

Example: convert buffer to base64 javascript

var buffer = Buffer.from('hello');//create a buffer of the text "hello"
//right now, buffer == <Buffer 68 65 6c 6c 6f>
var string64 = buffer.toString('base64');
//the .toString operator can set encoding
//string64 == 'aGVsbG8='