Update stylelint & stylelint-config-wagtail packages, adopt a subset of new rules

[lb-]

Overview

Closes #10719

This PR does not aim to align 100% with the new stylelint-config-wagtail updates but will ensure we do not get a huge amount of warnings when running npm install.

Instead, the goal is to adopt any auto 'fixing' of our styles files and a subset of easy to adopt rules without this PR being a huge item to review.

This also means that new styles added can align with the rules as they are in place and we avoid adding more complex styles than we already have (i.e. in the area of selector-max-combinators or selector-max-specificity.

Implementation notes

• Ensure that some rules are always ignored in overrides (aka vendor) styles. This avoids us having to add ignore comments all over these styles.
• Formatting & ordering (auto applied), this includes the padding/inset shorthand changes
• Adopt a small set of no-union-classes changes as an example of changes to come in future PRs
• Ignore some areas where we are selecting against data* attributes that will not be practical to change
• Move some no-important ignore rules to specific lines
• Ignore max-combinators in modeladmin styles (legacy)
• Remove error messages forced-color-adjust setting to none

Testing notes

There is only one functional change: Messages in high contrast mode (with and without dark mode).

Future work

There are potentially 100s of additional changes to make to fully align with the stylelint-config-wagtail base styles.

Once merged, I will look at raising some issues that help us get incremental steps towards alignment, these will be potentially good first issues (for ones that are just renames of classes for example).

[squash-labs]

Manage this branch in Squash

Test this branch here: https://lb-feature10719-update-styleli-1c89f.squash.io

[lb-]

Updated to be less strict again about block ordering & removed/cleaned up a few ordering items. Also resolved a few conflicts.

Would be great to get a review on this one so it does not have to be kept up to date with ongoing work in Wagtail. I have done my best to keep this PR to an absolute minimum and it helps our Node install process from showing so many warnings.

See wagtail/stylelint-config-wagtail#37 & wagtail/stylelint-config-wagtail#39

[lb-]

Need to manually rebase.

[thibaudcolas]

Thank you @lb-! I’d like to further discuss declaration-block-no-redundant-longhand-properties before we enforce it in Wagtail so I’ve taken those changes out for now, I hope that’s ok.

I’ve also moved the overrides to overrides/** to be directly inside the files – as there are fewer than what the config suggests.

Also worth noting this includes a Sass update which introduces deprecation warnings (one related to shorthand properties which I took out, one which I’ll address separately). When we update our dependencies via transitive updates like this, I think it’d be nice to keep the package.json up-to-date – so I’ve done that.

This doesn’t change which version is installed, just avoids a bit of confusion if our package.json says ^1.0.0 or similar but actually it’s resolving to 1.69.5.

[thibaudcolas]

I see only two of those rules currently raising issues, and only in two files from our overrides, so I think we’d be better off with in-file overrides here.

[lb-]

Good call thank you.

[thibaudcolas]

I’ve opened wagtail/stylelint-config-wagtail#41 and wagtail/stylelint-config-wagtail#42 as possible follow-ups.

[lb-]

Thanks @thibaudcolas - I agree with the shorthand properties thing. From the outside it seems like a helpful feature but it does make changing code harder. Thanks for reviewing and resolving those items.