<===> input.scss
#{bar},
[foo="#{bar}"],
[foo="#{bar}"] {
    content: "foo";
}

<===> output.css
bar,
[foo="bar"],
[foo="bar"] {
  content: "foo";
}

<===> output-dart-sass.css
bar,
[foo=bar],
[foo=bar] {
  content: "foo";
}