fs-extra
fs-extra contains methods that aren't included in the vanilla Node.js fs package. Such as recursive mkdir, copy, and remove.
braces
Bash-like brace expansion, implemented in JavaScript. Safer than other brace expansion libs, with complete support for the Bash 4.3 braces specification, without sacrificing speed.
chokidar
Minimal and efficient cross-platform file watching library
normalize-path
Normalize slashes in a file path to be posix/unix-like forward slashes. Also condenses repeat slashes to a single slash and removes and trailing slashes, unless disabled.