Для обычного встроенного <code> используйте:
<code>...</code>
и для каждого места, где требуется блокировка <code>, используйте
<code style=display:block;white-space:pre-wrap>...</code>
В качестве альтернативы определите<codenza> тег для блока разрыва подкладки <code> (без классов)
<script>
</script>
<style>
codenza, code {} /* noop mnemonic aide that codenza mimes code tag */
codenza {display:block;white-space:pre-wrap}
</style>`
Тестирование: (NB: ниже приведен сценарий, использующий протокол data: URI/ схема, поэтому коды формата %0A nl необходимы для сохранения, например, при вырезании и вставке в строку URL для тестирования - так что view-source: ( ctrl - U) хорошо выглядит перед каждой строкой ниже с %0A)
data:text/html;charset=utf-8,<html >
<script>document.write(window.navigator.userAgent)</script>
<script></script>
<style>
codenza, code {} /* noop mnemonic aide that codenza mimes code tag */
codenza {display:block;white-space:pre-wrap}
</style>
<p>First using the usual <code> tag
<code>
%0A function x(arghhh){
%0A return "a very long line of text that will extend the code beyond the boundaries of the margins, guaranteed for the most part, well maybe without you as a warrantee (except in abnormally conditioned perverse environs in which case a warranty is useless)"
%0A }
</code>
and then
<p>with the tag blocked using pre-wrapped lines
<code style=display:block;white-space:pre-wrap>
%0A function x(arghhh){
%0A return "a very long line of text that will extend the code beyond the boundaries of the margins, guaranteed for the most part, well maybe without you as a warrantee (except in abnormally conditioned perverse environs in which case a warranty is useless)"
%0A }
</code>
<br>using an ersatz tag
<codenza>
%0A function x(arghhh){
%0A return "a very long line of text that will extend the code beyond the boundaries of the margins, guaranteed for the most part, well maybe without you as a warrantee (except in abnormally conditioned perverse environs in which case a warranty is useless)"
%0A }
</codenza>
</html>