Support for CSS modules about vue-jest

[eddyerburgh]

Option B would be the best approach, I won't have time to implement it for a few weeks. Would you be able to make a PR?

If not, we could do option A as a quick fix.

[LinusBorg]

I am off work for the coming week, would try a PR.

[danielbastos11]

Any updates? I'd love to help if needed.

[danielbastos11]

I just made a PR using option B.
I made three decisons:

1. I decided to use extract-from-css instead of string-extract-class-names because the latter would claim .5px is a CSS class in letter-spacing: 0.5px. The former seems to work just fine.

2. In order to inject the mock object into the component, I am using a code like the following at the end of the output (take a look the PR for the actual version):

;(function() {
  var render = _Component.render
  _Component.render = function(h) {
    this['$style'] = {/* mock object */}
    return render.call(this, h)
  }
})()

I don't know if there's a better way to do this. Let me know if there is.

3. I added Stylus as a peer dependency, since other users might use SASS, for instance. This is causing the tests to fail, though. (they pass just fine once stylus is installed)

[lzgrzebski]

Im populating my colors from scss variables and Im using in through this. $style, but for some reason this is not working when running unit tests in jest, through yarn serve all works fine. Any ideas? Am I doing smth wrong?
`<style lang="scss" module>
@import '@/styles/variables.scss';
:export {
primary: $color-primary;
secondary: $color-secondary;

success: $color-success;
danger: $color-danger;
info: $color-danger;

light: $color-light;
white: $color-white;

}
</style>`

Why am I doing this? Im using in couple of places colors in js and want to have it in one place.
Inspiration comes from here css-modules/css-modules#86 (comment)

Currently Im just getting empty obj in jest and the object is populated normally when Im running the app.

Is this valid use case @eddyerburgh ?