I had the same problem and came across this quite old question. After investing for some time I finally found os.EOL at the very end of the os documentation.
var os = require('os')
console.log(JSON.stringify(os.EOL)) // prints "\n" on my Mac
JSON.stringify is in this case important, otherwise you would only see a blank line in the console (which makes sense because that’s what it should do). In an normal use case it is not needed.