Fix declaration-property-value-no-unknown parse error for multiline interpolation

[FloEdelmann]

What minimal example or steps are needed to reproduce the bug?

.foo {
  color: #{
    some-scss-function()
  };
}

What minimal configuration is needed to reproduce the bug?

{
  "rules": {
    "declaration-property-value-no-unknown": true
  }
}

How did you run Stylelint?

stylelint file.scss

Which Stylelint-related dependencies are you using?

{
  "stylelint": "^15.11.0",
  "stylelint-config-standard-scss": "^11.1.0"
}

What did you expect to happen?

No error, since interpolations should be ignored in the rule:

stylelint/lib/rules/declaration-property-value-no-unknown/index.mjs

Line 122 in da7ce21

if (!isStandardSyntaxValue(value)) return;

What actually happened?

A problem was reported:

Cannot parse property value "#{
    some-scss-function()
  }" for property "color" (declaration-property-value-no-unknown)

Do you have a proposal to fix the bug?

I think the regex here needs to be changed to also take newline characters into account:

stylelint/lib/utils/hasScssInterpolation.mjs

Line 1 in da7ce21

const HAS_SCSS_INTERPOLATION = /#\{.+?\}/;

[jeddy3]

@FloEdelmann Thanks for the report and for using the template.

The rule is only for CSS:

This rule is only appropriate for CSS. You should not turn it on for CSS-like languages, such as Sass or Less, as they have their own syntaxes.

Having said that, there's no harm in improving the interpolation to migrate this particular issue. You may encounter other issue trying to use the rule for SCSS, though.

I've labelled the issue as ready to implement. Please consider contributing if you have time.

There are steps on how to fix a bug in a rule in the Developer guide.