Versioning combined CSS files in Laravel 5.4 with Laravel Mix - laravel

Question

I am using Laravel Mix in Laravel 5.4 and I would like to combine to plain files and add versioning.
Reading the documentation it says
The version method will automatically append a unique hash to the
filenames of all compiled files, allowing for more convenient cache
busting
And it efectively does what it says. But is there any workaround to obtain a final combined file with versioning?
Actually I would like to join some compiled files together with other plain files and combine everything in a single versioned file.
Edit:
The code I am using is like the following
mix.sass('resources/assets/sass/app.scss', 'public/css')
.combine(['public/css/app.css', 'other/component/file.css'], 'public/css/all.css')
.version();
And I would like to obtain a versioned all.css file. i.e. something like all.d41d8cd98f00b204e9800998ecf8427e.css.
However what I get is a versioned version of the app.css and a non-versioned version of the all.css.

Answer 1

Versioning/Cache-Busting for CSS and JS files
Webpack.Mix
After combining my css (using mix.styles) and js (using mix.scripts) files into two files, I had all.css and all.js.
To add versioning, I did the following:
var timestamp = Date.now();
mix.copy('public/css/all.css', 'public/css/all/all.'+ timestamp + '.css');
mix.copy('public/js/all.js', 'public/js/all/all.'+ timestamp + '.js');
OR
Write it directly when you combine your css and js files, for example:
mix.styles([
'public/css/app.css',
'public/css/custom.css'], 'public/css/all/all.'+ Date.now() + '.css').
mix.scripts([
'public/js/app.js',
'public/js/custom.js'], 'public/js/all/all.'+ Date.now() + '.js').
Blade layout file:
I created /css/all/ and /js/all/ directories. I used the scandir() php function with ordering to get all of the files in the respective directories. Then I got the first filename from the array, which in this instance was 'all.1574160664960.css'.
#php($css_files = scandir('css/all/', 1))
<link href="/css/all/{{ $css_files[0] }}" rel="stylesheet">
#php($js_files = scandir('js/all/', 1))
<script src="/js/all/{{ $js_files[0] }}"></script>

Answer 2

https://laravel-mix.com/docs/5.0/versioning
In webpack.mix.js:
const mix = require('laravel-mix');
mix.js('resources/js/app.js', 'public/js')
.sass('resources/sass/app.sass', 'public/css')
.version();