gRegorNot really testing the representative h-card parsing itself (that's in the php-mf-cleaner lib), but the success/error messages shown, so I think I'd need to mock the HTTP request to /validate-h-card and parse the response.
gRegorCould add mf2 on the response page, maybe with a p-summary and check that? Seems like a lot of hoops though. mock http > get HTML > parse mf2 > assert based on some value in mf2