retain CSSList and Rule comments when rendering CSS

[Ruud68]

Hi,
was banging my head against the wall as my css comments would vanish when using a autoprefixer repo that utilizes this repo.
Found out that the issue was that comments are only partly implemented in this repo: they are recognized, but when rendering the parsed css code they are not added back.

So I rolled up my sleeves and did this PR.

This PR does two things:

1. fix the comments implementation as only the first comments where taken and not the subsequent comments in a CSSList
2. adds the comments back into the rendered CSS (as also requested in Parse Comments? #38 )

So this is my first PR in this repo, would love to have some feedback / discussion / tests :)

Thanks in advance,
regards, Ruud

[oliverklee]

@Ruud68 Thanks for contributing! ❤️

Two things:

• If this PR fixes two problems, is there a way we could separate it into two PRs?
• I'd really like to have this covered with tests (that fail without the change and pass with it). Would you be willing to add those?

[Ruud68]

Fix: remove this otherwise 'next' comment will be not set

[Ruud68]

@oliverklee the fix is actually a very small one, I have added it as a comment to the code in the PR.
As for the tests: I have no idea how to do that and how to test if the changes to the tests are correct. I need to check how that is done

[oliverklee]

@Ruud68 I'll check what would be a good place for you to start with the tests.

[Ruud68]

okay thanks @oliverklee I spent greater part of the day reverse engineering the code for these changes (not documented) and had a quick look at the unit tests. I do not think this will be a quick add for me (the tests) :(

[Ruud68]

@oliverklee learned a lot :) did some small changes and fixed unittesting.... I hope :)

[sabberworm]

Thanks @Ruud68 for the great work! I took the liberty of making rendering comments optional (by way of a OutputFormat setting), defaulting to off, for backwards-compatibility.

[Ruud68]

Thanks @Ruud68 for the great work! I took the liberty of making rendering comments optional (by way of a OutputFormat setting), defaulting to off, for backwards-compatibility.

My pleasure, glad I could contribute. making it optional is definitely a good option :)