The IDL is using StaticRange: https://github.com/WebKit/WebKit/blob/main/Source/WebCore/Modules/highlight/Highlight.idl
AbstractRange was implemented in https://trac.webkit.org/changeset/268648/webkit
So we could now update the Highlight API to accept AbstractRange and match the spec: https://drafts.csswg.org/css-highlight-api-1/#highlight
Otherwise most of the WPT tests that use Range() will fail in WebKit: https://wpt.fyi/results/css/css-highlight-api
Created attachment 438953 [details]
Looks like we haven't imported the css/css-highlight-api WPT tests.