Maybe this should be the default? Currently proseWrap: true causes issues in BitBucket server because its version of Markdown is much more sensitive to line breaks.

It will be an actual breaking change if we change the default, though the change is to preserve linebreaks, not sure if we should do so.

@vjeux Thoughts on making this the default?

I am not a fan of the current default, breaking words to 80 columns for markdown is imo a bad idea. Honestly I think that the best default would be to put everything in one line, but making preserve would be a step in the right direction from my point of view.

The playground option should be in another PR, tracked in #3338.

So this basically means prettier won't touch paragraphs all all? If so I'd prefer the default being all in a single line - I expect prettier to normalize stuff not just ignore inconsistencies.

I do think this option is a good alternative, but I do think the value proposition of either of the two existing options are higher

I originally choose "always" by default as it looks the most "prettier"-style, wrapping everything fits the printWidth, but if we're talking about the correctness, "preserve" should be the best since the markdown renderer used by GitHub comment/BitBucket are linebreak-sensitive, or if we're talking about which one is the most useful, it should be "never".

I don't have strong preference here.

My vote goes towards making "preserve" the default.

@SimenB In principle I agree, but unfortunately (as @ikatyang mentioned) there are multiple variants of Markdown that are all a little different when it comes to line breaks, so, to me, favouring not breaking the rendering of existing Markdown makes sense for the default value.

LGTM.