Desktop: Move CodeMirror 6 editor out of beta

[personalizedrefrigerator]

The CodeMirror 6 beta editor on desktop still has a number of issues that need to be addressed before it can be considered stable:

• Plugin API documentation -- Chore: Plugins: Add CodeMirror 6 plugin tutorial #9933
• Fix search highlighting not synced between viewer and editor. (Desktop: CM6 beta editor: Search highlighting not synced with viewer #9197)
• Auto-indent doesn't work in code blocks with no recognised type.
• Toggle comment doesn't work (see Desktop: Fixes #10007: Fixed Toggle Comment & Delete/Duplicate/Sort Line Options in Beta Editor #10016)
• Enable multiple cursors (CodeMirror 6 beta editor: Multiple cursors are enabled, but missing the ability to alt+drag (as in the CodeMirror 5 editor) #9196) and fix the related list issue (Desktop: CM6 beta editor duplicates list items when indenting with multiple selections #9200)
• Themes -- use colors from existing CodeMirror 5 themes in CodeMirror 6.
• Upgrade some of the most popular plugins to CodeMirror 6
  • Rich Markdown -- Desktop: Improve beta editor support for the Rich Markdown plugin #9935
  • Quick Links -- Support CodeMirror 6 roman-r-m/joplin-plugin-quick-links#15
    • Requires further work when other autocomplete plugins are enabled. CodeMirror 6 editor: Fix Quick Links conflict with other autocomplete plugins roman-r-m/joplin-plugin-quick-links#17 allows fixing an issue.
  • Inline tags -- Support CodeMirror 6 roman-r-m/joplin-inline-tags-plugin#10
  • Math mode
    • Seems to only sometimes work in CodeMirror 6. Possibly related to this issue? (This may be a regression...)
  • Multimarkdown table tools (Support CodeMirror 6 FelisDiligens/joplin-plugin-multimd-table-tools#7)
    • Status: Waiting for review.
  • Note link system
  • Themes: MacOS theme, ReMoods theme
  • Enhancement -- CodeMirror 6 support SeptemberHX/joplin-plugin-enhancement#63
    • I originally thought that making Enhancement compatible with CM6 would be a very large amount of work. For at least 2-3 of its main features, this might not actually be the case.

List of known broken plugins

• Partial: Rich Markdown -- changes to support CM6 not released.
• Partial: MacOS theme, ReMoods theme
  • CodeMirror themes don't work
• Partial: Note link system
  • Non-CodeMirror features work
• Partial: Math mode
• No support: Better codeblocks
• No support: Enhancement

[laurent22]

Thanks for creating this plan!

How many active CodeMirror plugins are there? I wonder if it really makes sense to spend a lot of time on this compatibility layer if we could simply fix the few that are out there?

Also once we make this editor the default, I think we should restrict access to the compatibility layer to existing plugins only. New plugins should not use it at all. Maybe like it's been done here, or similar solution:

joplin/packages/lib/services/plugins/api/JoplinSettings.ts

Line 11 in 2c0f8d5

const registerSettingAllowedPluginIds: string[] = [

[personalizedrefrigerator]

How many active CodeMirror plugins are there?

Based on a GitHub code search, I estimate 20-50 (code search).

Also once we make this editor the default, I think we should restrict access to the compatibility layer to existing plugins only. New plugins should not use it at all.

This makes sense.

Perhaps we could have a separate method for registering content scripts. For example,

joplin.contentScripts.register(
            ContentScriptType.CodeMirror6Plugin,
            ...
)

In this case, CodeMirror6 plugins could export a CodeMirror 6 extension.

Notes:

• Our CodeMirror compatibility layer extends CodeMirror-vim's compatibility layer, so we aren't maintaining all of it.
• CodeMirror 6's extension system is very different from CodeMirror 5's.
• If I recall correctly, one of the biggest issues we have when updating CodeMirror is multiple copies of global objects (e.g. facets) such that equality checks fail (copy1 !== copy2). For this reason, it may be necessary for us to export these static objects to plugins.