Concat files in directory

[endrehegyi]

Is it possible to concat all files in a directory?

Let's say I have a folder with 20 js files, I want to concat all of them but listing it individually in an npm script is rather tedious.

I tried "my_modules/js/*.js" which doesn't work - but it would be awesome if it did. In this case it would get all the files with .js extension in that folder.