DataInheritance cop similar to StructInheritance

[bdewater]

Is your feature request related to a problem? Please describe.

https://github.com/rubocop/rubocop/blob/master/lib/rubocop/cop/style/struct_inheritance.rb exists because using the bad form creates a useless anonymous class (as documented):

irb(main):001:0> class MyStruct < Struct.new(:foo); end
=> nil
irb(main):002:0> MyStruct.ancestors
=> [MyStruct, #<Class:0x0000000105e95790>, Struct, Enumerable, Object, PP::ObjectMixin, Kernel, BasicObject]

Ruby 3.2's Data class has the same issue, so it makes sense to have that cop (or a new cop) detect the same pattern:

irb(main):003:0> class Point < Data.define(:x, :y); end
=> nil
irb(main):004:0> Point.ancestors
=> [Point, #<Class:0x0000000105e9ef70>, Data, Object, PP::ObjectMixin, Kernel, BasicObject]

Describe the solution you'd like

# bad
class Point < Data.define(:x, :y); end

# good
Point = Data.define(:x, :y)

Describe alternatives you've considered

N/A

Additional context

N/A

[ktopolski]

Hey 👋

If this issue is free for grabs I'd love to work on it! Been using rubocop for years and would love to contribute back to the community 😅

[bdewater]

Go for it!

[MatheusRich]

@koic @bdewater I wonder if we should revert this or improve it.

Using inheritance is a very straightforward way to create constants within a class:

class MyClass < Data.define(:foo, :bar)
  A_CONST = 1
end