Resources

module ActiveRecord
  class Migration

    # Receives a version of ActiveRecord as a float
    # Return a Class
    def self.[](version)
      class_name = "V#{version.to_s.gsub(".", "_")}" # => "V7_0"
      ActiveRecord.const_get(class_name)
    end

    def add_column(table_name, column_name, column_type)
      puts "Adding #{column_name} to #{table_name} table"
    end
  end

  class V7_0 < Migration
    def add_column(table_name, column_name, column_type)
      puts "Adding #{column_name} to #{table_name} table with old version 7.0"
    end
  end

  class V8_0 < Migration
  end
end

class AddEmailToUsers < ActiveRecord::Migration[7.0]
  def change
    add_column :users, :email, :string
  end
end

class AddNameToUsers < ActiveRecord::Migration[8.0]
  def change
    add_column :users, :name, :string
  end
end

AddEmailToUsers.new.change
AddNameToUsers.new.change