That mixin was very useful for importing font files. I have slightly improved it for my use case (I was using it inside an ember addon).
$font-url: '/<app/addon name>/fonts';
@mixin font-face($name) {
@font-face {
font-family: $name;
src: url("#{$font-url}/#{$name}.woff2") format("woff2"),
url("#{$font-url}/#{$name}.woff") format("woff");
}
}
@include font-face('font--name-400');
body {
font-family: 'font--name-400';
}