This rule was added in rubocop 1.44.0. It's useful to avoid accidental
`unless !condition` clauses.
Note we aren't replacing `unless zero?` with `if nonzero?` because we
never use `nonzero?`; using it sounds like `if !zero?`.
Replacing `unless any?` with `if none?` is only consistent if we also replace
`unless present?` with `if blank?`, so we're also adding this case. For
consistency, we're also replacing `unless blank?` with `if present?`.
We're also simplifying code dealing with `> 0` conditions in order to
make the code (hopefully) easier to understand.
Also for consistency, we're enabling the `Style/InverseMethods` rule,
which follows a similar idea.
We were inconsistent on this one. I consider it particularly useful when
a method starts with a `return` statement.
In other cases, we probably shouldn't have a guard rule in the middle of
a method in any case, but that's a different refactoring.
This way we can easily add a test which will fail if by accident we
change the method to use `Date.today`. Until now using `Date.today`
would only fail if we ran specs in a time zone with a different date.