Codes of global.js file of my global package:

let fileName = '',
    port = '';


newArgv = process.argv.slice(2);

if (newArgv[0] === '-db' && newArgv[1] !== '') {
    fileName = newArgv[1];
} if (newArgv[2] === '-port' && newArgv[3] !== '') {
    port = newArgv[3];
}

jsonSpot(fileName, port);

And jsonSpot(fileName, port); is in another file which is the code below:

myFunction = (entryFileName, entryPort) => {

    let fileName = entryFileName || 'db.json',
        port = entryPort || 4000;

...

I open my CMD and write the command below:

myPackage --db myDb.json --port 3000

And it works.

The command below, works too (port 4000 is considered by default as I've written):

myPackage --db myDb.json

But the another command doesn't and always port 4000 is considered by the rest of my code (here port 3000 should be considered):

myPackage --port 3000

What's the problem with my code?

Is there anything wrong with my commands codes or they are related to other parts (absolutely other parts aren't being shown)?

Thanks