Adding a class nomobile will delete content from the mobile domain and is used and documented in a variety of places.

I was surprised to hear that classes that match nomobile and tried a few that match and can see that the hypen does cause problems so this is a bug that will probably have to be worked around for the time being by not using -

The issue is in https://github.com/wikimedia/html-formatter/blob/master/src/HtmlFormatter.php#L183 which is bundled in core via composer. I'm not sure how to tag that correctly... but this is indeed a bug. @Aklapper do you know which tags would be appropriate?

Maybe this is a good motivation for adopting Remex?

Alright, I have now added a warning to the German WP project pages. In my case I have simply renamed the class in hidemobile for the moment.

In T231160#5438018, @Jdlrobson wrote:

The issue is in https://github.com/wikimedia/html-formatter/blob/master/src/HtmlFormatter.php#L183 which is bundled in core via composer. I'm not sure how to tag that correctly... but this is indeed a bug. @Aklapper do you know which tags would be appropriate?

It doesn't look like we have a tag for the HtmlFormatter library, which would be the correct tag for it.

This analysis seems to be correct. The linked line should be something like

$elements = $xpath->query( '//*[contains(concat(" ", normalize-space(@class), " "), " ' . $classToRemove . ' ")]' );

Other XPath code in that library should probably also be checked for similar issues.

Ran into the same problem today with a sidebar template being corruped due to one portion of a larger infobox being stripped out due to containing the sequence navbox despite not matching the selector .navbox.

Change 615238 had a related patch set uploaded (by Krinkle; owner: Krinkle):
[HtmlFormatter@master] tests: Add regression tests for ignoring "foo" in "telefoon"

https://gerrit.wikimedia.org/r/615238

Change 615239 had a related patch set uploaded (by Krinkle; owner: Krinkle):
[HtmlFormatter@master] Fix incorrect matching of ".foo" on <span class="foo-something">

https://gerrit.wikimedia.org/r/615239

(Not sure who maintains this library but it's not reading web)

It was created in Reading Web's MobileFrontend and today is only used by the MobileFrontend and TextExtracts extensions. It was moved from the MF repo to a library repo in 2013 to allow re-use in TextExtracts and later CirussSearch (the latter no longer uses it).

At what point did you decide to transfer it to a different team, and who did it move to? :)

@Jdlrobson This is a bug in MobileFrontend either way. It could also be fixed by not using HtmlFormatter, for example.

It was created in Reading Web's MobileFrontend and today is only used by the MobileFrontend and TextExtracts extensions

Please remember, Reading web != mobile web team (the team that created that extension). The "mobile web" team no longer exists and hasn't for about 5 years. Looking at the history, it looks like Max Semenik was the last person to touch this code and he hasn't been in the team for just as long, so maintenance responsibilities for this likely slipped through the net.

At what point did you decide to transfer it to a different team, and who did it move to? :)

Well the reality is we are not maintaining it and never have been :). I think the point here is that nobody has asked "reading web" to maintain it and it shouldn't be assumed we are just because there was once someone in our team who created it. FWIW I don't think we'd be good maintainers for the same reasons we're not good maintainers of TextExtracts given T256505.

Change 615238 merged by jenkins-bot:
[HtmlFormatter@master] tests: Add regression tests for ignoring "foo" in "telefoon"

https://gerrit.wikimedia.org/r/615238

Change 615239 merged by jenkins-bot:
[HtmlFormatter@master] Fix incorrect matching of ".foo" on <span class="foo-something">

https://gerrit.wikimedia.org/r/615239

We can help with qa and sign off since this impacts mobile html.

I've just cut the next HtmlFormatter release.

Change 616562 had a related patch set uploaded (by Krinkle; owner: Krinkle):
[mediawiki/core@master] Update wikimedia/html-formatter to 2.0.0

https://gerrit.wikimedia.org/r/616562

Change 616563 had a related patch set uploaded (by Krinkle; owner: Krinkle):
[mediawiki/vendor@master] Update wikimedia/html-formatter to 2.0.0

https://gerrit.wikimedia.org/r/616563

Change 616563 merged by jenkins-bot:
[mediawiki/vendor@master] Update wikimedia/html-formatter to 2.0.0

https://gerrit.wikimedia.org/r/616563

Change 616562 merged by jenkins-bot:
[mediawiki/core@master] Update wikimedia/html-formatter to 2.0.0

https://gerrit.wikimedia.org/r/616562

Test Result - Beta

Status: ✅ PASS
Environment: beta
OS: macOS Catalina
Browser: Chrome
Device: MBP
Emulated Device: iPad

Test Artifact(s):

QA steps

Create a new page with the text

<div class="xenomobile">I should display on mobile</div>
<div class="nomobile">I should not display on mobile</div>

✅ AC1: In desktop both elements should be visible.

✅ AC2: In mobile site only 1st element should display

The test case is flawed I think because xenomobile was never an issue in production, e,g. comparing the same on production in a Sandbox also works as expected today. The issue was when a dash is in the mix. For example xe-nomobile was wrongly seen as nomobile and not-navbox wrongly seen as navbox.

Consider these instead, which are currently broken in production:

<div class="xe-nomobile">I should display on mobile (xe-nomobile)</div>
<div class="nomobile">I should not display on mobile (nomobile) </div>

<div class="not-navbox">I should display on mobile (not-navbox)</div>
<div class="navbox">I should not display on mobile (navbox) </div>

@Edtadros apologies for the flawed test case. Can we re-run on beta cluster with @Krinkle suggestion ?

@Jdlrobson will do. @Krinkle thanks for the clarification.

Test Result - Beta

Status: ✅ PASS
Environment: beta
OS: macOS Catalina
Browser: Chrome
Device: MBP
Emulated Device: iPad

Test Artifact(s):

QA steps

Create a new page with the text

<div class="xe-nomobile">I should display on mobile (xe-nomobile)</div>
<div class="nomobile">I should not display on mobile (nomobile) </div>

<div class="not-navbox">I should display on mobile (not-navbox)</div>
<div class="navbox">I should not display on mobile (navbox) </div>

✅ AC1: In desktop four elements should be visible.

✅ AC2: In mobile site only the two mobile elements should display

Change 619485 had a related patch set uploaded (by Jdlrobson; owner: Jdlrobson):
[mediawiki/extensions/MobileFrontend@master] Hide vertical nav-boxes on mobile domain

https://gerrit.wikimedia.org/r/619485

@Jdlrobson I also filed a bug report for that this morning - https://phabricator.wikimedia.org/T260170 - feel free to close as a duplicate if this fix is currently being tracked here.

Change 619380 had a related patch set uploaded (by Jdlrobson; owner: Jdlrobson):
[mediawiki/extensions/MobileFrontend@wmf/1.36.0-wmf.3] Hide vertical nav-boxes on mobile domain

https://gerrit.wikimedia.org/r/619380

Change 619381 had a related patch set uploaded (by Jdlrobson; owner: Jdlrobson):
[mediawiki/extensions/MobileFrontend@wmf/1.36.0-wmf.4] Hide vertical nav-boxes on mobile domain

https://gerrit.wikimedia.org/r/619381

Change 619485 merged by jenkins-bot:
[mediawiki/extensions/MobileFrontend@master] Hide vertical nav-boxes on mobile domain

https://gerrit.wikimedia.org/r/619485

Change 619380 merged by jenkins-bot:
[mediawiki/extensions/MobileFrontend@wmf/1.36.0-wmf.3] Hide vertical nav-boxes on mobile domain

https://gerrit.wikimedia.org/r/619380

Change 619381 merged by jenkins-bot:
[mediawiki/extensions/MobileFrontend@wmf/1.36.0-wmf.4] Hide vertical nav-boxes on mobile domain

https://gerrit.wikimedia.org/r/619381

Change 619592 had a related patch set uploaded (by Jdlrobson; owner: Jdlrobson):
[operations/mediawiki-config@master] Update wgMFRemovableClasses

https://gerrit.wikimedia.org/r/619592

Mentioned in SAL (#wikimedia-operations) [2020-08-11T23:34:52Z] <urbanecm@deploy1001> Synchronized php-1.36.0-wmf.4/extensions/MobileFrontend/extension.json: 81d54b0ec82d0b78f723f9400031e918a4a143aa: Hide vertical nav-boxes on mobile domain (T231160) (duration: 01m 05s)

Change 619592 merged by jenkins-bot:
[operations/mediawiki-config@master] Update wgMFRemovableClasses

https://gerrit.wikimedia.org/r/619592

Mentioned in SAL (#wikimedia-operations) [2020-08-11T23:36:35Z] <urbanecm@deploy1001> Synchronized php-1.36.0-wmf.3/extensions/MobileFrontend/extension.json: c22d65ff9b2439f484ab8ccffed87b00e78c3ad2: Hide vertical nav-boxes on mobile domain (T231160) (duration: 01m 03s)

Mentioned in SAL (#wikimedia-operations) [2020-08-11T23:39:32Z] <urbanecm@deploy1001> Synchronized wmf-config/InitialiseSettings.php: 0f238f71c95c7bd7534c28abfac759fbb47f674f: Update wgMFRemovableClasses (T231160) (duration: 01m 03s)