strip-final-newline 
Strip the final newline character from a string/buffer
Can be useful when parsing the output of, for example, ChildProcess#execFile, as binaries usually output a newline at the end. Normally, you would use stdout.trim(), but that would also remove newlines at the start and whitespace.
Install
$ npm install strip-final-newline
Usage
const stripFinalNewline = require('strip-final-newline');
stripFinalNewline('foo\nbar\n\n');
//=> 'foo\nbar\n'
stripFinalNewline(Buffer.from('foo\nbar\n\n')).toString();
//=> 'foo\nbar\n'
License
MIT © Sindre Sorhus