Plain text diff

[fcollonval]

fixes #352, fixes #446

This build on #388 but using CodeMirror instead of Monaco. The reason to switch to CodeMirror is to fit better with the visual identity of JupyterLab and nbdime that both use CodeMirror to show code. But the diff are highlighted following a style closer to Monaco than the default CodeMirror addon.

Here is a preview:

The remaining tasks:

• Improve styling to inherit from JupyterLab codemirror styling so changing editor theme is propagate here
• Add gutter + and -
• Restructure mergeview.ts
• Open issues to link codemirror settings changed signal with diff widget to improve integration within jupyterlab

The diff/merge code comes from the merge addon of CodeMirror. This will allow to implement at low cost a plain text merge interface.
The major modification to the original code is the usage of diff-match-patch npm package and the default view for the two panels case is to set the old text on the left panel and the current one in the right panel.

[fcollonval]

@telamonian would you be willing to review this PR?

[telamonian]

ahh, I see you have another short PR for me, @fcollonval :)

I actually already started going over this PR last weekend, so I'll get through it

[telamonian]

A note requesting a future PR, a question, and a couple of minor import sorting niggles. Nothing blocking, so LGTM!

@fcollonval Are you the one who wrote mergeview.ts, or did you get from somewhere else? I'm mostly asking out of curiosity/being impressed. It's supposed to be a Typescript translation of https://github.com/codemirror/CodeMirror/blob/master/addon/merge/merge.js, right?

[fcollonval]

Thanks for the review @telamonian

As you have started creating follow-up issues, I'll merge this one. Feel free to open a new issue, if you think the diff theme for the dark them needs improvements.

Are you the one who wrote mergeview.ts, or did you get from somewhere else? I'm mostly asking out of curiosity/being impressed. It's supposed to be a Typescript translation of https://github.com/codemirror/CodeMirror/blob/master/addon/merge/merge.js, right?

I have not much credit. I copied the original JS file you referenced and modified it to get a Typescript file without too many ts-ignore and without breaking its features.

[damianavila]

@fcollonval @telamonian this is on master but not released yet, am I right? in general, Is the milestone associated with the PRs/issues a reliable way to follow the status quo? Should I look into other documents besides the roadmap? Thanks!