promote Performance/RedundantSortBy to Style/RedundantSortBy

[matkoniecz]

Unlike many other Performance cops Performance/RedundantSortBy is not making code less readable and is a good idea independent from performance improvements.

As #5977 will cause performance cops to be disabled by default I suggest to rescue this one

It may be also useful to expand description with a note that this change may improve performance (as it would no longer be implied)

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Other usual issue fields are not applicable - I spotted it during reviewing https://github.com/rubocop-hq/rubocop/blob/master/config/default.yml

#6637 ("promote Performance/LstripRstrip to Style/LstripRstrip") is a closely related issue that was fixed in #6870 by @anuja-joshi

There are also Performance/UnneededSort, Performance/Sample, Performance/RedundantMatch that also improve (at least in my opinion) code quality, independent from performance improvements but I think that creating now separate issues for them is a poor idea (if that would be a good idea I may create a separate issue for each, I am planning to do it also if RedundantSortBy would be fixed without fixing three additional ones).

[bbatsov]

Performance/UnneededSort, Performance/Sample, Performance/Sample

Seems you made some mistake here.

[matkoniecz]

Fixed.

[bbatsov]

Performance/UnneededSort, Performance/Sample, Performance/RedundantMatch

I agree about the first two, but RedundantMatch should stay in Performance IMO.

[matkoniecz]

I crossed it out in the report.

[matkoniecz]

@bbatsov Is it a good idea to look over Performance cops again whatever there is still something worth rescuing? Or is it something that you did already during making 32ed7d1 ?

[bbatsov]

Well, I not that worried about those cops as they are not going to die. :-) Took a quick look at some of the others, but nothing seemed like an obvious choice to go to style. Let me know if you have any ideas.

[matkoniecz]

RedundantMerge, RedundantSortBy, ChainArrayAllocation looks like candidates but I am not 100% sure, I am even less sure about RedundantBlockCall.

RedundantMatch was rejected.

Well, I not that worried about those cops as they are not going to die

I know, but I would be happy to have in optional performance add-on restricted to rules making code style worse, this way I can easily disable/enable them as a group.