Fix declaration-property-value-no-unknown false negatives for nested declarations

[romainmenke]

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

.foo {
	color: 10px; /* has a warning */
	color: red;
}

.foo {
	@media (screen) {
		color: 10px; /* no warning */
		color: red;
	}
}

I added color: red to make sure there weren't any false positives.

What minimal configuration is needed to reproduce the bug?

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

How did you run Stylelint?

Demo

Which Stylelint-related dependencies are you using?

{
  "stylelint": "latest",
  "stylelint-config-standard": "latest"
}

What did you expect to happen?

I expected to see two errors.
One for each color: 10px;.

What actually happened?

Only one error was reported, for the regular, unnested rule.

Do you have a proposal to fix the bug?

No response

[romainmenke]

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

Line 114 in c812dae

parent && isAtRule(parent)

I think this was intended to differentiate at rule descriptors from declarations.

Maybe we can use the list of allowed nested at rules : https://drafts.csswg.org/css-nesting/#conditionals

Specifically, these rules are capable of being nested group rules:
all the conditional group rules (@media, @supports)

• @layer
• @scope
• @container