Ignore import not working about rtlcss

[siamak2]

I found a dirty solution to fix it for now.
In webpack.mix.js:

const mix = require( 'laravel-mix' );
const fs = require( 'fs' );

mix.before( function () {
	let data = fs.readFileSync( 'node_modules/toastr/build/toastr.css' );
	data = "/*rtl:begin:ignore*/\n" + data + "\n/*rtl:end:ignore*/";
	fs.writeFileSync( 'resources/sass/toastr.css', data );
} )

In resources/sass/app.scss:

@import "toastr.css";

But I'm hoping that you would fix the warning so I can remove this dirty workaround.

[MohammadYounes]

@siamak2 You need not to process each file alone. The idea is to have the content placed between the directives then process the final file only.

Your workaround works too.

[siamak2]

I'm not processing each file alone.
I have one app.scss file that imports other styles. I just don't want rtlcss process specific file which in this case is toastr.css. because that file already have rtl support and rtlcss will revert everything.
I tried this but it didn't worked:

/*rtl:begin:ignore*/
@import "~toastr/build/toastr.css";
/*rtl:end:ignore*/

I know I can run rtlcss from command line on the generated css but I need laravel mix to recognize output file (for cache busting and file watcher)

[MohammadYounes]

This is not a problem with rtlcsss. Check the output file being passed to rtlcss, does it contain

/*rtl:begin:ignore*/
... content of toastr.css 
/*rtl:end:ignore*/

or

/*rtl:begin:ignore*/
/*rtl:end:ignore*/
... content of toastr.css 

?

[siamak2]

I'm not passing the compiled css to rtlcss.
I don't really know how laravel mix works under the hood but I'm instructing it to compile my scss and use rtlcss as a PostCss plugin:

mix.sass( 'resources/sass/app.scss', 'public/css', null, [
        require( 'rtlcss' )
    ] )

The fourth argument is array of PostCss plugins which I passed rtlcss as fourth argument.
The above code works fine for my other ignore blocks but it doesn't work for @import.
Output file of the above code doesn't have any rtlcss comments. I'm guessing that rtlcss removes them.