<===> input.scss
.foo {
    filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(
        src="#{foo}",
        sizingMethod='scale');
}

<===> output.css
.foo {
  filter: progid:DXImageTransform.Microsoft.AlphaImageLoader( src="foo", sizingMethod='scale');
}

<===> output-dart-sass.css
.foo {
  filter: progid:DXImageTransform.Microsoft.AlphaImageLoader( src="foo", sizingMethod="scale");
}