Node Find if Script Is Required or Invoked from Cli

Note to self

Node: Find if script is required or invoked from CLI

Analogous to python's if __name__ == '__main__': in node you can test if a file is being directly invoked from CLI as follows:

//somewhere inside app.js
if (__filename === process.argv[1]){
    console.log('Run from terminal');
}
$ node app.js
> Run from terminal