ExDoc assumes too much about the markdown modules

[tmbb]

The function ExDoc.Markdown.as_html/2 (https://github.com/elixir-lang/ex_doc/blob/master/lib/ex_doc/markdown.ex#L31) assumes that the markdown implementation will generate code blocks eant to be highlighted by javascript. It calls pretty_codeblocks/1 which mangles the resulting code blocks. This should be handled by the as_html/2 function in the markdown modules themselves (ExDoc.Markdown.{Cmark, Earmark, Hoedown}), which you alreade define. People who want to use custom implementations shoud render the code you want themselves.

I have a markdown implementation that highlights code using HTML and CSS (no javascript) and messing with the class of the code block is not very good in that case (I have my own css classes).

[tmbb]

PS: my "custom markdown implementation" is just earmark with a custom code highlighter.

[tmbb]

I'm aware that this is a breaking change for people who use their own markdown implementations (I don't think this is a thing, though) and might depend on you changing the code block class. If tou think it's best, I can simply output code that deals with your postprocessing step.

[josevalim]

Moving it to the markdown engine is the way to go, definitely. Can you please send a PR? We can move the convenience function to ExDoc.Markdown and the engines can call it as appropriate.

[josevalim]

Btw ExDoc has not reached 1.0 yet, so it gives us a bit more flexibility in regards to breaking changes.

[tmbb]

Done. #763

[ericmj]

Fixed in #763.