Call arrange() after group_by() + summarize()

[DavisVaughan]

Hi there, we ran revdeps for dplyr and your package appeared in our checks.

We have updated arrange() to now have an explicit .locale argument that defaults to American English. It previously respected the system locale, but this is more performant and reproducible across R sessions.

You currently rely on the resulting ordering of group_by(df, x) %>% summarize() matching the ordering you'd get back from arrange(df, x). Instead, we suggest explicitly calling arrange() after calling summarize() if you rely on that ordering, as it will no longer match arrange() automatically in the next version of dplyr.

If you install this PR, you will see that one of your tests fails because of this assumption. tidyverse/dplyr#6263

Luckily, the fix here is simple and work with both dev and CRAN dplyr! If you could merge this PR and then go ahead and send a release to CRAN, then we would greatly appreciate it. It will make releasing the next version of dplyr easier for us.

Thanks!

[jessekps]

Great catch, tnx. I certainly did not intend to rely on group_by's ordering. I'll have to check if it occurs anywhere else. I had planned the next cran release for end of next week and will include this fix

[jessekps]

the fix is currently on its way to cran

[DavisVaughan]

Thank you!