A cop to check erroneous next within reduce. #2581
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| @@ -170,6 +170,7 @@ | |||
| * `Style/Documentation` recognizes 'Constant = Class.new' as a class definition. ([@alexdowad][]) | |||
| * [#1608](https://github.com/bbatsov/rubocop/issues/1608): Add new 'align_braces' style for `Style/IndentHash`. ([@alexdowad][]) | |||
| * `Style/Next` can autocorrect. ([@alexdowad][]) | |||
| * [#????](https://github.com/bbatsov/rubocop/pull/????): New cop `Lint/NextWithoutAccumulator` finds bare `next` in `reduce`/`inject` blocks which assigns `nil` to the accumulator. ([@mvidner][]) | |||
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Thanks for the suggestions! |
mvidner
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Overall the cop looks good. Just squash those commits together and update the final message to match our commit message style. (and rebase of top of |
| describe RuboCop::Cop::Lint::NextWithoutAccumulator do | ||
| subject(:cop) { described_class.new } | ||
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| context 'given a reduce block' do |
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You can use shared examples for reduce and inject.
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Drop the |
mvidner
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Now the build seems to be failing. |
mvidner
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In a reduce (aka inject), the accumulator value must be maintained. If you want to short-circuit an iteration and do it with a `next` the accumulator will become `nil`. You should use `next acc`. For reference, here is a real bug reported in my team about such code: http://lists.opensuse.org/yast-devel/2015-11/msg00094.html
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I've fixed the build. Thanks for the comments! |
bbatsov
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A cop to check erroneous next within reduce.
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In a reduce (aka inject), the accumulator value must be maintained.
If you want to short-circuit an iteration and do it with a
nextthe accumulator will become
nil. You should usenext acc.For reference, here is a real bug reported in my team about such code:
http://lists.opensuse.org/yast-devel/2015-11/msg00094.html