Style/RedundantArrayFlatten can be unsafe when the Array contains empty Arrays and join uses a separator #14249
Description
> ['a', [], 'b'].flatten.join("\n")
=> "a\nb"
got corrected to:
> ['a', [], 'b'].join("\n")
=> "a\n\nb"
which is a different result. Should be mentioned in the docs, at least.
1.76.0 (using Parser 3.3.8.0, Prism 1.4.0, rubocop-ast 1.45.0, analyzing as Ruby 3.4, running on ruby 3.4.2) [x86_64-linux]
- rubocop-rails 2.32.0
- rubocop-minitest 0.38.1
- rubocop-performance 1.25.0
- rubocop-capybara 2.22.1