In T373711#11464890, @Escargot_rouge wrote:

With CodeMirror, there is now a lot of red waves under word that are not recognised by the browser
Would it be possible to tell browsers not to show these waves inside CodeMirror with Vue, JS, CSS ans Lua contentmodels?

I've filed T412848 and submitted a patch. As an alternative, we could add a preference for spellchecking, if there's any demand for it? Otherwise we'll just hard-code it to disable spellcheck for non-wikitext.

In T373711#11465178, @Mr._Starfleet_Command wrote:

Also, double-clicking at the start or end of a bracket pair (...), [...], or {...} should highlight all the text between the brackets, like it does with CodeEditor.

Neat! I did not realize this existed. I believe we should be able to do this easily enough in CodeMirror. I've filed T412849.

Some UI/UX suggestions, based on comparing with CodeEditor:

CodeMirror	CodeEditor

• CodeMirror is missing the indentation grid lines which are present in CodeEditor.
• In the gutter, CodeMirror puts the linter icons to the right of line numbers, creating a lot of empty space when there are no warnings (as in screenshot). CodeEditor puts them to the left of line numbers, which feels more natural.
• The caret in CodeMirror is thin and sometimes almost invisible. CodeEditor's thick caret seems better.
• CodeEditor always highlights the active line. In CodeMirror, it is behind advanced preferences and off by default. I think it should be on by default for code.

@SD0001 I can't see the screenshots:

CodeMirror	CodeEditor

T310833 strikes again! As noted above, the screenshots are not visible :(

CodeMirror is missing the indentation grid lines which are present in CodeEditor.

I've filed T412883: Offer indentation grid lines in CodeMirror. This is not easy per-se as grid lines aren't offered in CM6, but there are various community solutions out there.

It might also be worth noting that the "highlight whitespace" feature might suffice as an alternative, if the code is indented with tabs and not spaces.

In the gutter, CodeMirror puts the linter icons to the right of line numbers, creating a lot of empty space when there are no warnings (as in screenshot). CodeEditor puts them to the left of line numbers, which feels more natural.

T412884: Move linter icons to the left of line numbers

The caret in CodeMirror is thin and sometimes almost invisible. CodeEditor's thick caret seems better.

T412885: Make the CodeMirror caret a bit thicker for readibility

CodeEditor always highlights the active line. In CodeMirror, it is behind advanced preferences and off by default. I think it should be on by default for code.

T412886: Enable active line feature by default in non-wikitext

r1218368 did not include Vue. Was that intentional?

In T373711#11468796, @Bhsd wrote:

r1218368 did not include Vue. Was that intentional?

No! Though it does remind me we still don't have linting there :/ Neither does CodeEditor, though, so I'll go ahead and enable it.

Change #1219250 had a related patch set uploaded (by MusikAnimal; author: MusikAnimal):

[operations/mediawiki-config@master] Use CodeMirror instead of CodeEditor for beta feature users + vue mode

https://gerrit.wikimedia.org/r/1219250

Change #1219250 merged by jenkins-bot:

[operations/mediawiki-config@master] Use CodeMirror instead of CodeEditor for beta feature users + vue mode

https://gerrit.wikimedia.org/r/1219250

Mentioned in SAL (#wikimedia-operations) [2025-12-18T02:47:01Z] <musikanimal@deploy2002> Started scap sync-world: Backport for [[gerrit:1219250|Use CodeMirror instead of CodeEditor for beta feature users + vue mode (T373711)]]

Mentioned in SAL (#wikimedia-operations) [2025-12-18T02:49:16Z] <musikanimal@deploy2002> musikanimal: Backport for [[gerrit:1219250|Use CodeMirror instead of CodeEditor for beta feature users + vue mode (T373711)]] synced to the testservers (see https://wikitech.wikimedia.org/wiki/Mwdebug). Changes can now be verified there.

Mentioned in SAL (#wikimedia-operations) [2025-12-18T02:54:15Z] <musikanimal@deploy2002> Finished scap sync-world: Backport for [[gerrit:1219250|Use CodeMirror instead of CodeEditor for beta feature users + vue mode (T373711)]] (duration: 07m 15s)

In T373711#11466971, @Bugreporter2 wrote:

@SD0001 I can't see the screenshots:

Me too, these two screenshots are restricted.

@MusikAnimal, after our conversation before, let's say that I'm open to try. When it will start working on Beta I'll turn it on and just see how it's going, maybe it will be fine, who knows. I even tried today, thought it's already on, but looks like not yet, CodeMirror already replaced ACE there, but does not work. You can ping me here after the experiment will start, if you're interested.

In T373711#11467068, @MusikAnimal wrote:

T310833 strikes again! As noted above, the screenshots are not visible :(

oops, fixed it.

Thanks for creating the subtasks and resolving most of them so quickly!

The caret in CodeMirror is thin and sometimes almost invisible. CodeEditor's thick caret seems better.

This is especially so when the cursor is next to a matching bracket. Adding .cm-cursor { border-left-width: 2px !important; } to my CSS solved it, but I wonder if it can be upstreamed.

Adding .cm-cursor { border-left-width: 2px !important; } to my CSS solved it, but I wonder if it can be upstreamed.

That is T412885. I would backport it but I understand there are no deploys until January 5. I'll be out on sabbatical until March 1, but the fix is there and will ride the first deployment train of 2026.

Same goes for any other changes at this point. I can ask Release Engineering, but I assume we won't be permitted to deploy anything until early January. You will be able to check for improvements on the Beta Cluster in the meantime, however.

Keep the feedback coming! I will be working on CodeMirror for the next week until my computer is shut off on January 1. (But after that you still have Bhsd, SD0001 and whoever else to keep things tidy :)

CodeMirror should turn links in CSS/JavaScript comments (e.g. /* [[link]] */) into clickable links like it does for such links in wikitext, and like already happens when viewing the page, not editing it (i.e. viewing the page directly, showing preview, or viewing an old revision).

In T373711#11476925, @IKhitron wrote:

@MusikAnimal, after our conversation before, let's say that I'm open to try. When it will start working on Beta I'll turn it on and just see how it's going, maybe it will be fine, who knows. I even tried today, thought it's already on, but looks like not yet, CodeMirror already replaced ACE there, but does not work. You can ping me here after the experiment will start, if you're interested.

Is there something new about when you're turning on the linters? Thank you.

One difference I notice between CodeEditor and CodeMirror when it comes to CSS and JavaScript is that, when you're writing code that's indented (i.e. within one or multiple block statements/functions), if you click "enter" twice to create a blank line between one piece of code and another, CodeMirror gets rid of the tabs from that line, whereas CodeEditor leaves them. I personally don't mind this change, and in my experience dropping the tabs is indeed more typical behavior for CSS/JS editors, but I just wanted to make a note of it.

In T373711#11483922, @IKhitron wrote:

In T373711#11476925, @IKhitron wrote:

@MusikAnimal, after our conversation before, let's say that I'm open to try. When it will start working on Beta I'll turn it on and just see how it's going, maybe it will be fine, who knows. I even tried today, thought it's already on, but looks like not yet, CodeMirror already replaced ACE there, but does not work. You can ping me here after the experiment will start, if you're interested.

Is there something new about when you're turning on the linters? Thank you.

Somebody, please? Because last time I checked the linters do not work, do not find programming languages errors, it's just text editor. Thank you.

In T373711#11494767, @IKhitron wrote:

Somebody, please? Because last time I checked the linters do not work, do not find programming languages errors, it's just text editor. Thank you.

The JavaScript/CSS/JSON/Lua linters work well for me. Have you enabled the "Improved Syntax Highlighting" beta feature?

In T373711#11494774, @Bhsd wrote:

In T373711#11494767, @IKhitron wrote:

Somebody, please? Because last time I checked the linters do not work, do not find programming languages errors, it's just text editor. Thank you.

The JavaScript/CSS/JSON/Lua linters work well for me. Have you enabled the "Improved Syntax Highlighting" beta feature?

Thank you for the answer. It was already enabled. Weird. I tried the simplest error, a double field in JSON, like

...
"name": "...",
"name": "...",
...

and didn't get any error.

In T373711#11494778, @IKhitron wrote:

Thank you for the answer. It was already enabled. Weird. I tried the simplest error, a double field in JSON, like

...
"name": "...",
"name": "...",
...

and didn't get any error.

Unfortunately, we (and official CodeMirror) have only implemented a very basic JSON linter using JSON.parse(). JSON objects with duplicate keys are still valid JSON, so no syntax error will be reported.

I see. I hope, at least all the linters will be ready until the ACE removing, to avoid regression. Thanks again.

In T373711#11494780, @IKhitron wrote:

I see. I hope, at least all the linters will be ready until the ACE removing, to avoid regression. Thanks again.

Ace editor seems to use a deprecated JSON parser which does not recognize some real syntax problems, such as {"Numbers cannot have leading zeroes": 013}.

Well, if the replacement linter will recognize not just all as before, but more, it's even better. Until then, I hope people will have a choice which editor to use.

A choice is not needed. Forward and onward. We can't hold back for every single thing. If it's good enough for Firefox, Google Chrome and Visual Studio Code, then it's good enough for us, even if it is not completely the same as before.

On the other side, there is a choice now, between ACE and wikieditor, with the "<>" button. And you can simply add the CodeMirror to this wikieditor. So people could continue to enjoy both worlds.

I have created task T413880. I will try to port a latest version of json_parse.js used in Ace.

In T373711#11495882, @Bhsd wrote:

I have created task T413880. I will try to port a latest version of json_parse.js used in Ace.

Thanks a lot! As a very heavy Mediawiki JSON user, really appreciate it.

I noticed that bracket matching is incorrect inside regex: escaped brackets are matched with unescaped brackets. I do not know if it should be corrected or if bracket matching should be disabled inside regex.

In T373711#11551779, @Escargot_rouge wrote:

I do not know if it should be corrected or if bracket matching should be disabled inside regex.

Unless we create and nest a regex sublanguage, brackets in regex are just like plain text, so it is unlikely to be corrected. However, I will try to disable it inside regex.

I've told you elsewhere that Regex should be its own content-model, but you're like "yeah, nah, it's gonna be replaced soon," - but that was years ago, and it still hasn't been replaced!

In T373711#11552284, @Bugreporter2 wrote:

I've told you elsewhere that Regex should be its own content-model, but you're like "yeah, nah, it's gonna be replaced soon," - but that was years ago, and it still hasn't been replaced!

Please feel free to create a task.

... that task is irrelevant to rouge's issue anyway. (T392330)

In T373711#11552386, @Izno wrote:

... that task is irrelevant to rouge's issue anyway. (T392330)

It's totally relevant. If you parse it as Regex as something not Regex - !Regex, then it'll throw all sorts of errors. If you parse Regex as Regex, then it'll work.

Change #1237630 had a related patch set uploaded (by Bhsd; author: Bhsd):

[mediawiki/extensions/CodeMirror@master] CodeMirror: only sync editor font preference for Wikitext

https://gerrit.wikimedia.org/r/1237630

Change #1237630 merged by jenkins-bot:

[mediawiki/extensions/CodeMirror@master] CodeMirror: only sync editor font preference for Wikitext

https://gerrit.wikimedia.org/r/1237630

Change #1238357 had a related patch set uploaded (by Bhsd; author: Bhsd):

[mediawiki/extensions/CodeMirror@master] CodeMirror: add `mw-editfont-monospace` class to non-Wikitext

https://gerrit.wikimedia.org/r/1238357

Change #1238357 merged by jenkins-bot:

[mediawiki/extensions/CodeMirror@master] CodeMirror: add `mw-editfont-monospace` class to non-Wikitext

https://gerrit.wikimedia.org/r/1238357

Change #1252605 had a related patch set uploaded (by Bhsd; author: Bhsd):

[mediawiki/extensions/CodeMirror@master] bracketMatching: ignore JavaScript RegExp literal

https://gerrit.wikimedia.org/r/1252605

Change #1252605 merged by jenkins-bot:

[mediawiki/extensions/CodeMirror@master] bracketMatching: ignore JavaScript RegExp literal

https://gerrit.wikimedia.org/r/1252605