[python-committers] mention-bot is dead, long live the (misnamed) CODEOWNERS file!

[Christian Heimes]

On 2017-08-01 22:59, Brett Cannon wrote:
> For those of you who have not noticed, mention-bot is no more. We were
> using the free instance that Facebook provided, but it seems to have
> fallen over and it doesn't look like it's going to get fixed soon
> (https://github.com/facebook/mention-bot/issues/230).
> 
> But while mention-bot was down, GitHub launched a new feature that
> serves a related purpose. While mention-bot tried to guess who should
> review a PR based on who has committed (which led some of us to get
> mentioned a lot simply from having touched a bunch of files), that
> didn't guarantee people got listed as a reviewer when they specifically
> wanted to be (e.g. Christian wanting to know about PRs touching our
> hashing or SSL code).
> 
> But GitHub launched CODEOWNERS to cover that latter case
> (https://help.github.com/articles/about-codeowners/ ). Now the filename
> is misleading since it doesn't necessarily mean someone owns the code
> (there's an option to make it feel like that, but we will never flip
> that on), but basically what the file does is let us specify who should
> automatically be added as a review of a pull request when files changed
> by the PR match one of the rules in CODEOWNERS. We have now created the
> file thanks to Mariatta
> (https://github.com/python/cpython/blob/master/.github/CODEOWNERS) and
> started with what we had in our .mention-bot file (which was just some
> rules for Christian). But if there are any files you want to
> automatically be listed as a reviewer on automatically, then please add
> an appropriate rule to that file (remember that being listed as a
> reviewer doesn't require that you review else you block a PR from being
> merged, so don't view it as some major commitment).
> 
> Now to start we can specify individual people. But if there end up being
> groups of people who want to be added to reviews on certain topics (e.g.
> Eric, Nick, and myself for importlib stuff), then we can create
> sub-teams on GitHub of the Python Core team and then that team can be
> listed for the rule. To create a team just tell me who is on the team --
> all of whom will be made admins so teams are self-organized
> post-creation -- and what the team name should be (e.g. importlib-team).
> Then you can reference the team by e.g. @python/importlib-team (I think
> team names, even when nested, are not nested when mentioning so we will
> probably want to have a "-team" suffix for all teams to make it clear
> it's a subteam and not to clash with higher-level teams like
> @python/asyncio or @python/typing).

Marietta, Brett, thanks for your work!

I suggested teams to make the file a bit easier to maintain. The rule
format works differently than the old mentionbot format. In the old
format we had a relationship user -> files. The new CODEOWNERS format
has files -> users mapping with last rules trumps all semantic. We have
to be careful to not override parts of a previous rules. I believe teams
reduce the burden.

Christian