Constants in super classes not overridden by child classes

constants-not-overridden.rb

# It appears that a base class method refers to the constant value in that method
# instead of the constant value declared in child classes.
# You have to use a method to provide the expected behavior.
class BaseClass
  COLUMNS = []

  def self.shared_processor
    child_processor(COLUMNS + ['column1'])
  end
  
  def self.alternative_processor
    child_processor(columns_method + ['baseColumn'])
  end
end

module Area1
  class Connector < BaseClass
    COLUMNS = %w(column2 column3)

    def self.child_processor(value)
      return value + ['area1_column']
    end
    
    def self.columns_method
      ['area1Column']
    end
  end
end

module Area2
  class Connector < BaseClass
    COLUMNS = %w(column5 column6)

    def self.child_processor(value)
      return value + ['area2_column']
    end

    def self.columns_method
      ['area2Column']
    end
  end
end

# Direct reference to constant works
BaseClass::COLUMNS # => []
Area1::Connector::COLUMNS # => ["column2", "column3"]
Area2::Connector::COLUMNS # => ["column5", "column6"]

# COLUMNS used is the one defined in base class, because it uses
# the value of COLUMNS present when the class method was defined
Area1::Connector.shared_processor # => ["column1", "area1_column"]
Area2::Connector.shared_processor # => ["column1", "area2_column"]

Area1::Connector.alternative_processor # => ["area1Column", "baseColumn", "area1_column"]
Area2::Connector.alternative_processor # => ["area2Column", "baseColumn", "area2_column"]