Too Long; Didn't Read
In a previous post, I discussed why Sass unit testing is a thing and why you may want to incorporate it into your project. Unit testing Sass functions isn’t too complicated but what about mixins? Testing-wise, it is quite similar. Let’s create a simple viewport mixin similar to the `screen-above()` mixin defined in [Cirrus]. The mixin below will apply styles if it is larger than the specified breakpoints. An error is thrown if the breakpoint does not exist.