Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.14)
// Compass (v1.0.3)
// ----

@mixin foo($out: false) {
  @if $out {
    @at-root { @content; }
  }
}

@mixin bar() {
  @at-root { @content; }
}

@mixin baz($string) {
  @at-root .#{$string} { @content; }
}

.test {
  @include foo(true) {
    .nest1 {
      color: red;
    }
  }
  @include bar() {
    .nest2 {
      color: green;
    }
  }
  @include baz('nest3') {
    color: blue;
  }
  @at-root {
    .nest4 {
      color: yellow;
    }
  }
}

SassMeister-output.css

.nest1 {
  color: red;
}
.nest2 {
  color: green;
}
.nest3 {
  color: blue;
}
.nest4 {
  color: yellow;
}