<===> input.scss
:nth-child(2n + 3) {
  outer-whitespace: false;
}

// Regression test for sass/dart-sass#465.
:nth-child( 2n + 3 ) {
  outer-whitespace: true;
}

<===> output.css
:nth-child(2n + 3) {
  outer-whitespace: false;
}

:nth-child(2n + 3) {
  outer-whitespace: true;
}

<===> output-dart-sass.css
:nth-child(2n+3) {
  outer-whitespace: false;
}

:nth-child(2n+3) {
  outer-whitespace: true;
}