Maybe I don't understand the problem, but code shouldn't get automatically line-wrapped, since doing so might affect the behavior of it in a lot of languages.

@Lundin - I think the wrap can be achieved by using overflow-wrap: break-word; or similar. You will get the text displayed on multiple lines, but no actual line breaks are there (copy-pasting it in a text editor will get a single line). A similar behaviour is happening while editing code with long lines.

Or the code blocks with lines too long for the space should get scrollbars so they stay in bounds without anything getting truncated. I don't know what's better here, scrolling or auto-wrap, but either would be better than letting them get so wide that they don't fit and over/underlap other content.

I'm thinking the root of the problem might be the programmer who writes 140 symbols long LoC and not the site?