[css-typed-om][css-values] What context is CSSNumericValue.parse(...) considered to have for its parse?

[weinig]

In most (I believe all other) cases, when parsing a calc() expression there is a known "context" which is needed to determine the type of percentage values. This is needed to figure out if the type should be a dimension with a percent hint (like when parsing a width property), or raw percentage (like when parsing scale).

With CSSNumericValue.parse(...) however, there is no specified context.

How are percentages supposed to be interpreted when parsed in this way?

[weinig]

cc @tabatkins, @fantasai

[tabatkins]

Correct, there isn't a specified context, so the paragraphs conditioned on the context don't apply.

As far as I know, the behavior should work out either way - if you have a value that works due to having a known context, then parsing it without a known context then matching it against a grammar should always work as well. Getting that right has been difficult and subtle; if you find an instance where it fails, it's a spec bug.