User:SPage (WMF)/SyntaxHighlight test

A bad lang attribute in <source> tag used to display an ugly error box. Now it just displays preformatted text with no highlighting. Good for readers, bad for editors. And there's no link to available languages while editing wikitext.

These bad <source> tags will put this page in Category:Pages with syntax highlighting errors, but when you preview they don't warn.

: <source lang="bad">bad value for lang attribute </source>
: <source code="html5">wrong tag attribute 'code'</source>
: <source>no lang attribute</source>