Defining default values for mixins defined in JS file

Sorry; this is likely due to my lack of understanding. I have a mixin defined in a JS file — it takes a couple of arguments so I am attempting to define it like this:

MakeSpinner: function ($backgroundColor, $highlightColor)  {
        return {
            "content": "''",
            "border": "'2px solid ' + $backgroundColor",
            "border-left-color": $highlightColor,
            "border-radius": "999px",
            "opacity": "0"
        };
    }

However, I get the error Undefined variable $backgroundColorwhich makes some sense as this is an argument rather than an actual variable.

How should I be writing this?

[ai]

@benfrain JS mixins accepts a rule in first argument (I forget it too 😃 ). Here is a fixed version:

MakeSpinner: function (rule, $backgroundColor, $highlightColor)  {
        return {
            "content": "''",
            "border": '2px solid ' + $backgroundColor,
            "border-left-color": $highlightColor,
            "border-radius": "999px",
            "opacity": "0"
        };
    }

[ai]

@benfrain definitely! 😃