Spaces and linebreaks after # and around { } messing up interpolation/mixins (SASS/SCSS)

[mtbpm]

original scss:

@mixin itemPropertiesCoverItem($items, $margin) {
  width:              calc((100% - ((#{$items} - 1) * #{$margin}rem)) / #{$items});
  margin:             1.6rem #{$margin}rem 1.6rem 0;
}

beautified scss:

@mixin itemPropertiesCoverItem($items,
$margin) {
  width: calc((100% - ((# {
    $items
  }
  - 1) * # {
    $margin
  }
  rem)) / # {
    $items
  }
  );
  margin: 1.6rem # {
    $margin
  }
  rem 1.6rem 0;
}

problem:

Spaces and linebreaks are inserted after # and around { }. This creates obsolete lines and breaks SASS-Interpolation, which is needed for mixins.

Also notice the obsolete linebreak in between "$items," and "$margin".