Upgrade to react-codemirror2

[raisedadead]

We should consider moving to https://github.com/scniro/react-codemirror2 which promises an actively maintained replacement of our current component.

• The current component maintainers are non-responsive about all activities on their tracker and there is a discussion Deprecate react-codemirror JedWatson/react-codemirror#126 by the community of a more maintained version.
• The replacement (react-codemirror2) maintainers are having codemirror as a peer dependency.

Doing so is way better going forward as a part of preventive upgrades/maintainance.

Additional related topics:

• Code mirror accessibility discussion is being tracked in Contents of editor can not be reviewed by screen readers #12431 (comment)

[raisedadead]

@BerkeleyTrue @QuincyLarson do you think this is okay for the road map?

[BerkeleyTrue]

@raisedadead I haven't noticed any issues with react-codemirror. After all it is a thin wrapper around codemirror. That being said it looks like it might be worth the upgrade. I don't think this has anything to do with accessibility, though.

[raisedadead]

Oh yes, it has nothing to with a11y, I just happened to link to the issue, incase we are patching CM as per discussions in the thread, this might be affected.

Adding this to roadmap.

[no-stack-dub-sack]

@raisedadead @BerkeleyTrue One of the current problems with react-codemirror, is that if we ever want to upgrade to newer versions of React, react-codemirror will pretty much completely cease to work, as it has not been maintained at all since the early days of React. I tried to use react-codemirror for a project using React 16 and had considerable difficulty, and switching to react-codemirror2 instantly solved my problems. That said, can't remember what those problems were.

[BerkeleyTrue]

@no-stack-dub-sack thanks for the info. Sounds like a solid reason to upgrade.

[QuincyLarson]

Note we've switched to Monaco so I'm closing this issue.