from #4423 (review):

I think that we should start to figure out a way to do those kind of library-specific kind of transforms into plugins.

There are a lot of downsides with the current approach of bundling it inside of prettier:

• Now we need to maintain all those ourselves
• If jest changes their format, then you need to wait a new prettier release to be able to use it. This dramatically slow down iteration speed
• Ideally jest would be in control of how their format their templates
• We have a good relationship with jest but what if some library coming from someone else wanted to format their thing, we now have to figure out what specific library printing is worth being inside of prettier.