My example, was perhaps too simple seeing how the functions are very short... I'm sure someone will mention making long functions is a bad idea... but it happens... using const for required modules seems like a simple rule to follow for avoiding trouble... Also, stylistically using an uppercase lettering while not normal in node.js community is normal to JS in other contexts... jQuery... getElementById.. perhaps Fs if you prefer however looking through mozilla code as a guideline - variables declared const are uppercase... hence FS makes better sense to me... because why would a module variable name ever not be... and in the rare case that it is.. declare it var at least until let is available...