Option to use Document.parseHTMLUnsafe instead of DOMParser for parsing HTML?

[lukewarlow]

Currently HTMX is using new DOMParser().parseFromString() for parsing the HTML responses. This is fine enough for most use cases and makes sense given the browser support is better.

However, one big limitation of this is it doesn't support Declarative Shadow DOM. For this there's a newer Document.parseHTMLUnsafe() function.

Would it make sense to provide a mechanism to use the newer function?

[lukewarlow]

Just to note the unsafe naming is there because in future we'll get a "safe" version (called parseHTML that has a built in sanitiser and all that nice stuff), so parseHTMLUnsafe is no less safe than parseFromString.