normalizeNewlines.js

// remove empty lines and multiple carriage return/newline
var lines = "1\r\n\n\n\n2\n3\n\n      \n\n"
             .replace(/^\s*$/mg, '') // remove empty lines
             .replace(/[\r\n]+/g, '\n') // all carriage return/newline
             .replace(/\n$/, '') // remove newline at end
             .split('\n');