Re: [csswg-drafts] [cssom] Properties that allow access to parsed-but-invalid syntactic constructs (declarations, rules, etc) as a low-fi way to make polyfills easier (#13186)

My question exactly. I'm trying to write a scriptlet to walk all loaded stylesheets and catch invalid/unrecognized properties and attempt to convert them to valid ones, but standard CSSOM seems to provide no access to parsed-but-invalid properties.

Maybe an alternative solution would be to keep "invalid" properties along with valid ones in `CSSStyleDeclaration` and perhaps add a `.isValid(name)` method. That way the `CSSStyleDeclaration` would contain all original properties and thus be a more faithful representation of the actual underlying CSS statement. After all, "invalid" properties are still a part of the original CSS statement, even if not in use.

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Received on Thursday, 15 January 2026 16:10:58 UTC