Respectfully cc Bartosz because he fixed tables of contents in [[Special:Version]] and [[Special:SpecialPages]]

@Bugreporter2: A good first task is a self-contained, non-controversial task with a clear approach. It should be well-described with pointers to help a completely new contributor. Given the current short task description I'm removing the good first task tag. Please add details what exactly has to happen where and how for a new contributor, and then add back the good first task project tag. Thanks a lot in advance!

I think it is a relatively simple task. You could review my change for Special:SpecialPages: https://gerrit.wikimedia.org/r/c/mediawiki/core/+/891370/2/includes/specials/SpecialSpecialpages.php and make changes along these lines to SpecialMediaStatistics.php, adding id attributes and a table of contents.

@matmarex how can I populate my local database with existing data to test out if my fix is working or not?

Does something like this look correct to you

protected function outputResults( $out, $skin, $dbr, $res, $num, $offset ) {
			$tocData = new TOCData();
			$tocLength = 0;
			foreach ( $res as $row ) {
				$mediaStats = $this->splitFakeTitle( $row->title );
				if ( count( $mediaStats ) < 4 ) {
					continue;
				}
				[ $mediaType, $mime, $totalCount, $totalBytes ] = $mediaStats;
				if ( !str_contains( $mediaType, '/' ) ) {
					++$tocLength;
					$tocData->addSection( new SectionMetadata(
						1,
						2,
						$mediaType,
						$this->getLanguage()->formatNum( $tocLength ),
						(string)$tocLength,
						null,
						null,
						"mw-mediastatisticsgroup-$mediaType",
						"mw-mediastatisticsgroup-$mediaType"
					) );
				}
			}
			$pout = new \ParserOutput;
			$pout->setTOCData( $tocData );
			$pout->setOutputFlag( ParserOutputFlags::SHOW_TOC );
			$pout->setText( \Parser::TOC_PLACEHOLDER );
			$out->addParserOutput( $pout );
				foreach ( $res as $row ) {
			$mediaStats = $this->splitFakeTitle( $row->title );
			if ( count( $mediaStats ) < 4 ) {
				continue;
			}
			[ $mediaType, $mime, $totalCount, $totalBytes ] = $mediaStats;
			if ( $prevMediaType !== $mediaType ) {
				if ( $prevMediaType !== null ) {
					// We're not at beginning, so we have to
					// close the previous table.
					$this->outputTableEnd();
				}
				$this->outputMediaType( $mediaType );
				$this->totalPerType = 0;
				$this->countPerType = 0;
				$this->outputTableStart( $mediaType );
				$prevMediaType = $mediaType;
			}
			$this->outputTableRow( $mime, intval( $totalCount ), intval( $totalBytes ) );
		}
		if ( $prevMediaType !== null ) {
			$this->outputTableEnd();
			// add total size of all files
			$this->outputMediaType( 'total' );
			$this->getOutput()->addWikiTextAsInterface(
				$this->msg( 'mediastatistics-allbytes' )
					->numParams( $this->totalSize )
					->sizeParams( $this->totalSize )
					->numParams( $this->totalCount )
					->text()
			);
		}
	}

I tried to test this with mock data but I'm not sure if I structured my data correctly as it only worked when I removed the ' / ' check.

Change 1013002 had a related patch set uploaded (by Rockingpenny4; author: Rockingpenny4):

[mediawiki/core@master] Add anchor tag and table of contents

https://gerrit.wikimedia.org/r/1013002

In T326060#9628903, @Rockingpenny4 wrote:

@matmarex how can I populate my local database with existing data to test out if my fix is working or not?

The easiest way would probably be to just upload a few files of different types.

Hi! I’m a newcomer and would like to work on this task as my first contribution. Could I please be assigned?

@Somyaya: Welcome! Please first read the "New Developers" page on mediawiki.org and its Communication Tips section. Also see above that there is already a patch which needs rework. Thanks!

Change #1227575 had a related patch set uploaded (by Suraj Seth; author: Suraj Seth):

[mediawiki/core@master] SpecialMediaStatistics: Add anchor tags to group headings

https://gerrit.wikimedia.org/r/1227575

Change #1227614 had a related patch set uploaded (by Suraj Seth; author: Suraj Seth):

[mediawiki/core@master] fix(SpecialMediaStatistics): correct headerText variable name typo

https://gerrit.wikimedia.org/r/1227614

Change #1227614 abandoned by Suraj Seth:

[mediawiki/core@master] Add anchor links to Special:MediaStatistics headings

https://gerrit.wikimedia.org/r/1227614

Change #1227614 restored by Suraj Seth:

[mediawiki/core@master] Add anchor links to Special:MediaStatistics headings

https://gerrit.wikimedia.org/r/1227614

Change #1227614 abandoned by Suraj Seth:

[mediawiki/core@master] Add anchor links to Special:MediaStatistics headings

https://gerrit.wikimedia.org/r/1227614

Change #1240837 had a related patch set uploaded (by Suraj Seth; author: Suraj Seth):

[mediawiki/core@master] SpecialMediaStatistics: Add anchor tags to group headings

https://gerrit.wikimedia.org/r/1240837

Change #1227575 abandoned by Bartosz Dziewoński:

[mediawiki/core@master] SpecialMediaStatistics: Add anchor tags to group headings

Reason:

Replaced by https://gerrit.wikimedia.org/r/c/mediawiki/core/+/1240837

https://gerrit.wikimedia.org/r/1227575

Change #1240837 merged by jenkins-bot:

[mediawiki/core@master] SpecialMediaStatistics: Add anchor tags to group headings

https://gerrit.wikimedia.org/r/1240837

Change #1013002 abandoned by Bartosz Dziewoński:

[mediawiki/core@master] Special:MediaStatistics - Add anchor tag and table of contents

Reason:

The task has been resolved, and it looks like you're not longer active. Feel free to restore this patch if you want to keep working on the table of contents. Thanks!

https://gerrit.wikimedia.org/r/1013002

I don't want to make this even messier, but...

There's something weird going on with https://en.wikipedia.org/wiki/Special:MediaStatistics

There are now five separate headings all saying "Bitmap images" when presumably these should be combined. Did this patch break something else or is it an unrelated issue?

That's weird, but it can't be caused by this change.

OK T423978: Special:Mediastatistics is being weird and not grouping similar file types together is submitted separately.