Github PR is merged, so closing this as resolved.

Link to related Github PR: https://github.com/benapetr/wikimedia-bot/pull/76

I will add this.

I have added tests. Thank you for offering me to work on this on IRC!

I will add tests for this extension

This fixed the issue! Thanks everyone for your help! Can we use extension-unittests-composer instead of extension-unittests-composer-non-voting now, if it works good?

While working on this, I have noticed that in some extensions (for example WikiLexicalData) some classes are outside includes directory (need to take this into account while grep-ing). Additionally, some files are not loaded with autoloader, but are required from other files with require_once. I am not sure what to do with those. Do we need to replace require_once with autoloading first?

After enabling phpcs I noticed that there are a lot of rule violations here. I decided that it will be better to exclude all failing rules now and then fix them part-by-part in next patches. This will make code style fixes easier to review and merge. Additionally, I faced internal CodeSniffer error which I reported in T185642.

Thank you for your work @Osnard! Can we close this as resolved once https://gerrit.wikimedia.org/r/#/c/405853/ is merged?

I will add this and fix code style issues if those will be detected

tests/wikibase_tests.py::TestRedirects::test_normal_item ERROR: Logged in as '192.0.2.42' instead of 'Pywikibot-test'. Forcing re-login.

Hm, taking this into account, I think that the simplest solution would be just to edit cassette and replace 192.168.0.2.42 with Pywikibot-test in request which is reponsible for logging in.
Another possible (and maybe more correct) solution would be to write a custom cassette serializer/deserializer, so needed value (name of user used to run the test) is placed in cassette automatically on load.

Looks like cassette which was recorded does not contain one of requests:

CannotOverwriteExistingCassetteException: No match for the request (<Request (GET) https://www.wikidata.org/w/api.php?maxlag=5&format=json&rawcontinue=&meta=userinfo&action=query&uiprop=blockinfo%7Cgroups%7Chasmsg%7Crights>)

@Reedy Thank you! Then I will abandon my changes to core and fix extensions instead.

@Anomie Thank you for giving links to those tasks! You are right, there is no need to split files now if general reogranization will be done. So can we close this task as "Declined"?

There are quite a lot of such files in core so to make things simplier to manage, review and merge I will split it into multiple patches (by directories)

I will work on fixing this

Okay. Thank you for your work @Goraf! I have tested it once again (changing from 1 to 0 fixes the problem) and will push a patch now.

@Goraf Your explanation of this seems to be right. Do you have any plans to continue working on this? Maybe to provide a patch?

@Goraf thank you, I will take a look at it!