This will reduce the amount of different test "implementations" and
should further unify/normalise the tests. Some tests are very large and
can be split up more but this is a start in the right direction.
One of the biggest benefits is that changes in the tests file re-trigger
a jest run in watch mode. A change in the HTML/CSS file won't.
* Handle duplicate atrules without children
We assumed that all At Rule nodes had children. Including ones that do not and should not — for example `@import url(…);`. Since this is not the case we’ll skip adding children for nodes that don’t have any.
* Update changelog
Co-authored-by: Jordi Marimon Palarea <jordimarimon7@gmail.com>
* move `./tests/jit` to `./tests`
* make tests consistent
Abstracted a `run` function and some syntax highlighting helpers for
`html`, `css` and `javascript`.
