New rule: Unnecessary Method

[Blacksmoke16]

Given the following code:

abstract class Parent
  def initialize(@name : String); end
end

class Child < Parent
  def initialize(name : String)
    super
   end
end

The child's initializer isn't required since it is the same as the parent.

[veelenga]

To be more general, we can report any method which implements only call to super, correct?

[Blacksmoke16]

Probably as long as the params/types are the same. For example:

abstract class Parent
  def bark(name : String)
    pp name
  end
end

class Child < Parent
  def bark(name : String)
    super
   end
end

Would also be unnecessary.

abstract class Parent
  def bark(name : String)
    pp name
  end
end

class Child < Parent
  def bark(name : String, some_bool)
    super name
   end
end

Would be required since the params are not the same.

[veelenga]

I found this tricky way to expose parent's private method in std lib:

class A
  private def method(a)
    puts a
  end
end

class B < A
  def method(b)
    super
  end
end

B.new.method(10) #=> 10

maybe this is not the best architecture but it looks like the language intentionally allows it. So we don't want to disallow this by Ameba.

FYI Ameba is a syntax analyzer, meaning it can't get info about parent class (it can be located in a different file). So there is no way to distinguish between a real "unnecessary method" and the intentional call to super