T47850 got me thinking that maybe we should nip this in the bud and remove WikiEditor support entirely for non-wikitext? The current state of affairs is that WikiEditor very much assumes wikitext, and really all it's giving us is the toolbar. I can make a toolbar.

We don't want to remove WikiEditor for CodeMirror+wikitext as there are too many WikiEditor integrations. The same surely can't be said for non-wikitext. I think the CSS hack that CodeMirror and CodeEditor use probably prohibit most integrations from working.

I think this one is actually a really big bug, which might not be described correctly and in total above? It may be difficult to break this down into smaller tasks that can be fixed individually. Or the following may need a parent task, as this is going on about keyboard shortcuts?

Here's what I think:

• CodeEditor should be automatically toggled on any page that's code (CSS, JS, Scribunto) or simply plain text.
• The 5 wikitext elements on the main toolbar (bold, italic, link, media, references) and all those under “advanced” are useless clutter and should not be present on non-wikitext pages
• However, the “special characters” and “help” elements may be useful whatever the language, and should be part of the CodeEditor toolbar.

Additionally, some language-specific elements might be useful:

• Creating JavaScript redirects (which work differently to WikiText redirects)
• Inserting comments into code.

In T401271#11073622, @Bugreporter2 wrote:

I think this one is actually a really big bug, which might not be described correctly and in total above? It may be difficult to break this down into smaller tasks that can be fixed individually. Or the following may need a parent task, as this is going on about keyboard shortcuts?
…
CodeEditor

Before we go any further, let me make it clear this is about MediaWiki-extensions-CodeMirror, not CodeEditor. But assuming you did mean to say CodeMirror,

• should be automatically toggled on any page that's code (CSS, JS, Scribunto) or simply plain text.
• The 5 wikitext elements on the main toolbar (bold, italic, link, media, references) and all those under “advanced” are useless clutter and should not be present on non-wikitext pages

This is already the case.

• However, the “special characters” and “help” elements may be useful whatever the language, and should be part of the toolbar.

Typically non-wikitext is treated as code, which rarely contains diacritics or otherwise "special" characters. The "Help" panel as written currently appears to only be for wikitext. Either way both of those are from WikiEditor, so I'm inclined to hide them as WikiEditor doesn't know about non-wikitext (which is why I tagged it). But any such change to WikiEditor should probably be a different task, sorry. I've removed the tag.

Additionally, some language-specific elements might be useful:

• Creating JavaScript redirects (which work differently to WikiText redirects)

Do you mean a code snippet to do i.e. window.location.replace() or something similar? That seems rather niche. However, adding support for customizable snippets would be very cool! We could make it site configuration so specific projects can provide commonly needed snippets, etc.

• Inserting comments into code.

A button to add or even toggle comments is doable, and I see there are suitable icons in Codex. We can look into it!

For the issue at hand (wikitext-specific keyboard shortcuts working where they shouldn't), I'm thinking of going with a quick fix for now to simply disable CodeMirror-to-textarea event bubbling for non-wikitext.

Change #1178593 had a related patch set uploaded (by MusikAnimal; author: MusikAnimal):

[mediawiki/extensions/CodeMirror@master] CodeMirror: disable event bubbling to the textarea for non-wikitext

https://gerrit.wikimedia.org/r/1178593

Change #1178593 merged by jenkins-bot:

[mediawiki/extensions/CodeMirror@master] CodeMirror: disable keydown events on textarea for non-wikitext

https://gerrit.wikimedia.org/r/1178593