cmd/update-report: report outdated count & suggest brew upgrade

[Bo98]

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I've been wanting to do this for a while now.

This helps with the confusion people may have with the differences between brew update and brew upgrade.

With this change, brew update (via update-report) will now report how many installed formulae and casks are outdated and points the user to brew upgrade to update them.

[BrewTestBot]

Review period will end on 2021-02-10 at 20:51:22 UTC.

[MikeMcQuaid]

With this change, brew update (via update-report) will now report how many installed formulae and casks are outdated and points the user to brew upgrade to update them.

Can you benchmark (ideally with hyperfine) the speed difference here? The reason we've held off doing this historically is that outdated? checks are pretty slow.

We should definitely ensure this code isn't run on autoupdates.

[Bo98]

If there has been updates (and thus ReporterHub's updated formula report has printed) then this costs <0.1s because caching.

It's ~0.45s without but it perhaps depends on the number of formulae installed. (Tested with ~250 formulae, though only 2 casks)

[MikeMcQuaid]

If there has been updates (and thus ReporterHub's updated formula report has printed) then this costs <0.1s because caching.

It's ~0.45s without but it perhaps depends on the number of formulae installed. (Tested with ~250 formulae, though only 2 casks)

Cool. I'd suggest skipping when there's not been updates, then, or at least skipping when there's not been updates and it's an autoupdate.

[Bo98]

I'd suggest skipping when there's not been updates, then, or at least skipping when there's not been updates and it's an autoupdate.

I was leaning on the latter if we could afford it because "Already up-to-date" might be seen as confusing, but then I realised that message can be printed through update.sh (if HOMEBREW_DEVELOPER is not set) so it'll have to be the former.

[MikeMcQuaid]

Looks good so far!

[BrewTestBot]

Review period ended.

[dkav]

Could this message be excluded if --quiet is used?

[Bo98]

Possibly. The --quiet checks in update-report are quite sparse, but I wouldn't personally be against expanding that a bit. Best way is to guage opinion is to open a PR.