This is about whether it's OK for MediaWiki core to depend on other PHP libraries, and how to manage such dependencies.
Background: A while back, I proposed a simple class for assertions to be added to core[1]. It was then suggested[2] that this could be placed in a separate component, which could then be re-used by others via composer. Since the assertions are very little code and nicely self-contained, this should be easy to do.
However, if we want to use these in MediaWiki core, core would now depend on the assertion component. That means that either MediaWiki would require installation via Composer, or we have to bundle the library in some other way.
What's the best practice for this kind of thing? Shall we just make the assertion repo an git submodule, and then pull and bundle it when making tarball releases? Should we switch the generation of tarballs to using composer? Or should we require composer based installs in the future? Are there other options?
Cheers, Daniel
[1] https://www.mediawiki.org/wiki/Requests_for_comment/Assert [2] https://www.mediawiki.org/wiki/Talk:Requests_for_comment/Assert#Use_outside_...