JuliaControl Bot

[mfalt]

I thought we should have an issue discussing how we want the @JuliaControlBot to work.
Currently

• it compares a PR to the reference images in https://github.com/JuliaControl/ControlExamplePlots.jl and replies with changes, whenever an update to a PR is made, as long as the PR is made from a branch that belongs to JuliaControl.
• It also creates a branch with the updated plots under https://github.com/JuliaControlBot/ControlExamplePlots.jl/branches/
• The bot can be manually called by writing @JuliaControlBot test-plots, by one of the members of the JuliaControl organization.

Should we reduce the number of posts the bot makes in some way?
Should it delete old posts?
Should it refuse to run on PRs that are not up to date with master? Otherwise the bot might report false changes.
Should we automatically pull branches into ControlExamplePlots when a PR is pulled into master? Or maybe automatically run an update ControlExamplePlots whenever master changes?

Proposed changes:

• Bugfix: It seems like the bot recognizes some types of comments as changes and runs a new check and post
• Add link to the new branch on ControlExamplePlots in the PR reply (Fixed in JuliaControl/ControlExamplePlots.jl@d851414)

[baggepinnen]

Should we reduce the number of posts the bot makes in some way?

I don't think the current number of posts is disturbing

Should it delete old posts?

Might be confusing to read follow-up posts if the post they are following up on are gone

Should it refuse to run on PRs that are not up to date with master? Otherwise the bot might report false changes.

Sounds like a good idea

Should we automatically pull branches into ControlExamplePlots when a PR is pulled into master? Or maybe automatically run an update ControlExamplePlots whenever master changes?

Some form of automatic handling would be nice, because we (at least I) will probably forget otherwise. I can't judge between your two suggested strategies so feel free to choose :)