Refactoring: Refactorings/Remove Named Parameter

Logically the inverse of Introduce Named Parameter: The fluency that named parameters bring is no longer worth the complexity on the receiver. Converts the named parameter list back into a standard parameter list

Mechanics

1. Choose the parameter to remove from named parameter Hash. In receiving method, replace named parameter with a standard parameter (before the Hash, if there still is one).
2. Replace named parameter in calling code with a standard parameter
3. Test

Example

Before

class Books
  def self.find(hash={})
    hash[:joins] ||= []
    hash[:conditions] ||= ""
 
    sql = ["SELECT * FROM books"]
    hash[:joins].each do |join_table|
      sql << "LEFT OUTER JOIN #{join_table} ON"
      sql << "books.#{join_table.to_s.chap}_id"
      sql << " = #{join_table}.id"
    end
    sql << "WHERE #{hash[:conditions]}" unless hash[:conditions].empty?
    sql << "LIMIT 1" if hash[:selector] == :first   # oops, we want selector to be a required parameter...
 
    connection.find(sql.join(" "))
  end
end

After

class Books
  def self.find(selector, hash={})
    hash[:joins] ||= []
    hash[:conditions] ||= ""
 
    sql = ["SELECT * FROM books"]
    hash[:joins].each do |join_table|
      sql << "LEFT OUTER JOIN #{join_table} ON"
      sql << "books.#{join_table.to_s.chap}_id"
      sql << " = #{join_table}.id"
    end
    sql << "WHERE #{hash[:conditions]}" unless hash[:conditions].empty?
    sql << "LIMIT 1" if selector == :first
 
    connection.find(sql.join(" "))
  end
end