class RuboCop::Cop::Style::MixinUsage

Checks that ‘include`, `extend` and `prepend` statements appear inside classes and modules, not at the top level, so as to not affect the behavior of `Object`.

@example

# bad
include M

class C
end

# bad
extend M

class C
end

# bad
prepend M

class C
end

# good
class C
  include M
end

# good
class C
  extend M
end

# good
class C
  prepend M
end