This rule was added in Rubocop 0.89.0. However, there are some false
positives when we don't use interpolation but simply concatenate in
order to avoid long lines. Even if there weren't false positives, there
are places where we concatenate to emphasize the point that we're adding
a certain character to a text.
We might reconsider this rule in the future, since we generally prefer
interpolation over concatenation.
We were very inconsistent regarding these rules.
Personally I prefer no empty lines around blocks, clases, etc... as
recommended by the Ruby style guide [1], and they're the default values
in rubocop, so those are the settings I'm applying.
The exception is the `private` access modifier, since we were leaving
empty lines around it most of the time. That's the default rubocop rule
as well. Personally I don't have a strong preference about this one.
[1] https://rubystyle.guide/#empty-lines-around-bodies