[ShadyCSS] Parse css-mixins and @apply rules in Angular component-level styles

[firstor]

I am using Angular 4 and Polymer 2. The problem is that Polymer 2 supports css-mixins but Angular doesn't. So I need to parse css-mixins and @apply rules in Angular component-level styles. When I tried to use <custom-style> feature from Polymer 2, the css-mixins worked fine but the styles were messed up. :not(.style-scope) was appended to all style selectors and elements were decorated with style-scope class. I know that's how ShadeCSS emulates ShadowDOM v1 spec. But as I know, Angular also applies different scoping with ShadeCSS, so I only need to handle what Angular missed - css-mixins and @apply rules. So I am asking if there is any way to parse them only from the styles inside a certain element which can be retrieved like as document.querySelector()?

[dfreedm]

The @apply functionality is deprecated, and I'm not sure we want to make it work for more use cases. This may be a good candidate for #31 with ::part