Given <p> HI </p>, what per-spec is the expected result for running .innerText for that element?

I’m looking at https://github.com/LadybirdBrowser/ladybird/issues/4048, which is about that returning " HI " (whitespace preserved) in Ladybird — but returning "HI" (whitespace trimmed) in all other engines.

But looking the source at https://github.com/LadybirdBrowser/ladybird/blob/6b9e8cf40c89c75d95f855b5c244c3382984eaa9/Libraries/LibWeb/HTML/HTMLElement.cpp#L368 for the Ladybird implementation of the “get the text steps” https://html.spec.whatwg.org/multipage/dom.html#get-the-text-steps, it looks to me like Ladybird has correctly implemented the spec requirements.

So I’m wondering if the difference is due to a bug in Ladybird’s implementation — or else due to other engines not strictly implementing the spec requirements.

I think

If node is a Text node, then for each CSS text box produced by node, in content order, compute the text of the box after application of the CSS 'white-space' processing rules and 'text-transform' rules, set items to the list of the resulting strings, and return items.

Trims the text. For the same reason that the rendering of <p>Hi</p> is the same as the rendering of <p>\n Hi\n</p>.