How can I use Node.js to check if a directory is empty?

Question

I asked this question for PHP a long time ago. The same applies for Node.js the code below seems a little slow when using in a loop - is there a way for writing this in pure Node.js vanilla JavaScript without plugins or React.js etc?

const dirname = 'cdn-assets/'

fs.readdir(dirname, function(err, files) {
    if (err) {
       // some sort of error
    } else {
       if (!files.length) {
           // directory appears to be empty
       }
    }
});

Also, can I write a further conditional to check:

if(directory_has_these_files('.js, .css, .jpg, .svg, .mp4'))

Zardoz · Accepted Answer · 2018-06-29T09:01:27.170

So if you do this

fs.readdir('/path/to/empty_dir', (data, err) => console.log(data, '.....', err))

You'll see that the result is:

null '.....' []

So your code can be simplified as

fs.readdir(dirname, (err, files)  => {
if (err && !files) {
    console.error(err)
}

console.info('the files --> ', files)

let regexp = RegExp('.jpeg|.doc|.png|.zip', 'gi')

for(result in files) {
    if(regexp.test(files[result])) {
        console.log('I have the following', files[result])
    }
}});

However....

We want this quick, modern and efficient, don't we?!

So this is even better:

fs.readdir(dirname, (err, files)  => {
    if (err && !files) {
        console.error(err)
    }

    let regexp = RegExp('.jpeg|.doc|.png|.zip', 'gi');

    files.filter(
        file => file.match(regexp)
    ).map(
        result => console.log('I have the following',result)
    );

});

One of the advantages to using a map on a directory, is that you'll guarantee the preservation of order, it also looks cleaner.

Map is built-in iterable — Object is not, this is not to say the Map is a replacement for Object, there are use cases for both. That's another story.

How can I use Node.js to check if a directory is empty?

1 Answers1

However....