Update stylelint and the official WP package

[tomjn]

This contribute towards #274 by upgrading the official WP package used for configuration and upgrading stylelint to 14.2 which was required by the WP package update. This fixes some deprecation notices that show up downstream in projects

[tomjn]

@tfrommen there are changes necessary in addition to these, specifically handling of SASS/SCSS changed in Stylelint 14, but I forgot to mark it as a draft and can't find how to change it back

[tomjn]

found it, it's in the reviewers section of the sidebar

[mattheu]

there are changes necessary in addition to these, specifically handling of SASS/SCSS changed in Stylelint 14, but I forgot to mark it as a draft and can't find how to change it back

I'd love to push this PR forwards. What are these changes? Stylelint docs say that if you're wanting to lint scss files you need the rules in a separate package. But we're actually extending the WordPress stylelint config, which already handles this. So all is fine I think.

[tomjn]

I'd love to push this PR forwards. What are these changes? Stylelint docs say that if you're wanting to lint scss files you need the rules in a separate package. But we're actually extending the WordPress stylelint config, which already handles this. So all is fine I think.

@mattheu if you checkout the branch you'll see there's more to it than just updating the package, configs need accounting for as well as several unknowns I never reached because of that. In moving to a newer major version Stylelint made config changes as well as rule changes that I hadn't anticipated and didn't have time to investigate. If core have resolved those and we can upgrade by upgrading a dependency in WP then that's good but I'm unsure what additional changes are necessary here

[mattheu]

I know this was a while back so understand that you don't remember the details of what problems you hit, so i'll try and reproduce to see.

I checked out this branch and used it to lint the SCSS from a large project currently using @humanmade/stylelint-config v1.1.1. I'll summarise the issues below.

• The custom config on that project used the rules declaration-property-unit-blacklist and declaration-property-unit-whitelist which are now removed and should be replaced with declaration-property-unit-disallowed-list and declaration-property-unit-allowed-list.
• Some new rules now causing it to fail
  • No longer allowed to use scss global functions. e.g. switch from str-index to string.index
  • No longer allowed to use @extend with classes e.g. @extend .my-component and should prefer using extend placeholders.
  • No longer alllowed to use the preceeding underscore when importing a partial. e.g. @import "_partial should now be @import "partial" as sass handles this OK. Similarly no need to specify the extension so @import partial.scss` is also now flagged.

In my opinion, these changes are all fine and to be expected when updating to a new major release of the linting rules. We should ensure this is rolled out in a major release of our rules too, and document that there are some changes, but otherwise I see no problem with this.

[ntwb]

Via https://github.com/WordPress/gutenberg/blob/trunk/packages/stylelint-config/CHANGELOG.md

## 21.0.0 (2022-08-24)

### Breaking Change

    Increase the minimum Node.js version to 14 (https://github.com/WordPress/gutenberg/pull/43141).

## 20.0.0 (2022-01-27)

### Breaking Change

-   Increased minimum peer dependency of `stylelint` to `14.2.0` ([#38091](https://github.com/WordPress/gutenberg/pull/38091)). See [official migration guide to v14](https://github.com/stylelint/stylelint/blob/14.0.0/docs/migration-guide/to-14.md) for details.

## 19.0.0 (2021-01-21)

### Breaking Change

-   Increase the minimum Node.js version to 12 ([#27934](https://github.com/WordPress/gutenberg/pull/27934)).
-   Increased minimum peer dependency of `stylelint` to `13.7.0`.

### Bug Fixes

-   Fixed deprecation warning for `declaration-property-unit-whitelist`.