I checked VisualEditor, NWE and DiscussionTools so far on beta en.wiki with minervanightmode=1. Found the following issues:

VisualEditor:

Table header and cell content are not visible.

Article Read mode:
Table is not rendering completely.

DiscussionTools:

Reply tool toolbar is not visible:

None of the texts under Advanced section for Reply tool is visible:

Toolbar for new topic tool is not visible:

Texts under Advanced section for new topic tool is not visible:

The three dots for editing/reporting a topic/section on talk page is not visible:

The three dots for reporting a comment is not visible:

Now that the task description is updated with the issues @Ryasmeen identified in T360691#9678381, I'm assigning this task over to @ovasileva assess determine and document who might be best equipped to address each issue.

Note: if/when we come to learn any of these issues are relatively complex, the Editing and Web Teams will work together to determine what – if anything – we'll do in response.

In parallel, I've created T364420 where we will test Editing interfaces on desktop.

@Ryasmeen - we're having some trouble replicating the first two issues with tables appearing in light mode. Could you give us some steps for replication? Thank you!

@ovasileva: I am also not seeing those two issues anymore.

In T360691#9813703, @Ryasmeen wrote:

@ovasileva: I am also not seeing those two issues anymore.

Perfect!

Meta

Per offline discussions with @CCiufo-WMF and @Ryasmeen, the Editing Team is going to us a single ticket (this one) to document any and all changes we notice resulting from updating OOUI to use:

1. REM units
2. CSS variables

To put the above into practice, I've merged T364420 and T365521 into this task and expanded the scope of this task (and retitled it).

Per today's meeting with @Esanders, @Jdrewniak, @ovasileva, work on this task is blocked on DST merging the REM and dark mode changes into OOUI.

@CCiufo-WMF / @egardner: could y'all please comment here once the above is done so that the Editing Team knows when testing can begin?

In T360691#9861330, @ppelberg wrote:

Per today's meeting with @Esanders, @Jdrewniak, @ovasileva, work on this task is blocked on DST merging the REM and dark mode changes into OOUI.

@CCiufo-WMF / @egardner: could y'all please comment here once the above is done so that the Editing Team knows when testing can begin?

Hi @ppelberg – our goal is to finish up the work in OOUI this week, cut an OOUI release at the beginning of next week (tentatively called 0.50.rc-1) and then ship that to beta right away.

In T360691#9861561, @egardner wrote:

In T360691#9861330, @ppelberg wrote:

Per today's meeting with @Esanders, @Jdrewniak, @ovasileva, work on this task is blocked on DST merging the REM and dark mode changes into OOUI.

@CCiufo-WMF / @egardner: could y'all please comment here once the above is done so that the Editing Team knows when testing can begin?

Hi @ppelberg – our goal is to finish up the work in OOUI this week, cut an OOUI release at the beginning of next week (tentatively called 0.50.rc-1) and then ship that to beta right away.

All that you described above sounds great, @egardner.

Would it be alright for the Editing Team to expect a comment here y'all when everything is ready for testing by way of it landing on beta?

In T360691#9871593, @ppelberg wrote:

In T360691#9861561, @egardner wrote:

In T360691#9861330, @ppelberg wrote:

Per today's meeting with @Esanders, @Jdrewniak, @ovasileva, work on this task is blocked on DST merging the REM and dark mode changes into OOUI.

@CCiufo-WMF / @egardner: could y'all please comment here once the above is done so that the Editing Team knows when testing can begin?

Hi @ppelberg – our goal is to finish up the work in OOUI this week, cut an OOUI release at the beginning of next week (tentatively called 0.50.rc-1) and then ship that to beta right away.

All that you described above sounds great, @egardner.

Would it be alright for the Editing Team to expect a comment here y'all when everything is ready for testing by way of it landing on beta?

Hi @ppelberg – I'll comment on this task again when the new OOUI release is up on Beta. We plan to release it on Tuesday (June 11), after the train goes out.

However, it's possible to inspect things now in Patchdemo if you don't want to wait until then. This patchdemo instance applies the patches we are planning to merge into OOUI for the next release, and it also applies some config copied from production which disables dark-mode on most OOUI-intensive featuers like VE and special pages. You'll still want to make sure that the switch to rem units doesn't cause any sizing or alignment issues however (although in my own testing so far I only saw a few minor problems which have already been addressed).

https://patchdemo.wmflabs.org/wikis/61da5f7352/wiki/Main_Page

In T360691#9871803, @egardner wrote:

In T360691#9871593, @ppelberg wrote:

In T360691#9861561, @egardner wrote:

In T360691#9861330, @ppelberg wrote:

Per today's meeting with @Esanders, @Jdrewniak, @ovasileva, work on this task is blocked on DST merging the REM and dark mode changes into OOUI.

@CCiufo-WMF / @egardner: could y'all please comment here once the above is done so that the Editing Team knows when testing can begin?

Hi @ppelberg – our goal is to finish up the work in OOUI this week, cut an OOUI release at the beginning of next week (tentatively called 0.50.rc-1) and then ship that to beta right away.

All that you described above sounds great, @egardner.

Would it be alright for the Editing Team to expect a comment here y'all when everything is ready for testing by way of it landing on beta?

Hi @ppelberg – I'll comment on this task again when the new OOUI release is up on Beta. We plan to release it on Tuesday (June 11), after the train goes out.

However, it's possible to inspect things now in Patchdemo if you don't want to wait until then. This patchdemo instance applies the patches we are planning to merge into OOUI for the next release, and it also applies some config copied from production which disables dark-mode on most OOUI-intensive featuers like VE and special pages. You'll still want to make sure that the switch to rem units doesn't cause any sizing or alignment issues however (although in my own testing so far I only saw a few minor problems which have already been addressed).

https://patchdemo.wmflabs.org/wikis/61da5f7352/wiki/Main_Page

Wonderful – thank you for sharing this context and continuing to keep us informed, @egardner. We'll plan to start QA on Tuesday on Beta (if the release is on time) and on patchdemo if it is delayed.

cc @EAkinloose

Per what @egardner shared in Slack the latest OOUI release will NOT include a change to rem units.

I've updated the task description to reflect this.

In T360691#9882530, @ppelberg wrote:

Per what @egardner shared in Slack the latest OOUI release will NOT include a change to rem units.

I've updated the task description to reflect this.

Thanks @ppelberg. OOUI has been updated and released as of this morning, and it now includes the latest version of the Codex color tokens (which reference CSS custom properties, if defined, meaning that they should automatically change from light to dark colors along with the rest of the page). We performed this update manually and are (at least for now) not planning to move forward with updating OOUI to use rem units the way that Codex now does.

Hopefully this leads to few if any regressions in testing – especially since dark mode is disabled on many special pages still.

If you see any OOUI issues that will surface in production (as opposed to things that are limited to pages where dark mode is still disabled) please let us know!

@ovasileva to review and and take screenshots of current state.

Talk page dark mode QA

Per what @ovasileva and I talked about offline just now, we're going to do the following:

1. Web Team to retest issues labeled Re-test as part of T365509 in the task description
2. Web Team to do exploratory testing
3. Once "1)" and "2)" finish, Olga will ping Peter and at that point Editing can do comprehensive testing of talk pages in dark mode