Add nested CSS Selector support

[lelandrichardson]

For example:

wrapper.find('.foo .bar')

[ljharb]

ideally also .find('.foo > .bar'), and .find('.foo, .bar') :-)

[lelandrichardson]

@ljharb actually, .foo, .bar is already supported. But yes, ideally we'd also have .foo > .bar and also potentially .foo + .bar and .foo ~ .bar

Edit: Whoops. It's not. Sorry. I did actually start implementing commas though... just never finished.

[badeball]

Hi, @lelandrichardson

I've actually been thinking for a while about creating a CSS selector engine for the virtual DOM of React. Particularly because I recently released a DOM-agnostic XPath implementation that also works on it (which I personally have found to be very useful for the purpose of testing). Perhaps this can be of use to you?

[blainekasten]

Closing issue as PR has been merged! 🎉