Question

I have the following complex method. I’m trying to find and implement possible improvements. Right now I moved last if statement to Access class.

def add_access(access)
   if access.instance_of?(Access)
     up = UserAccess.find(:first, :conditions => ['user_id = ? AND access_id = ?', self.id, access.id])
     if !up && company
       users = company.users.map{|u| u.id unless u.blank?}.compact
       num_p = UserAccess.count(:conditions => ['user_id IN (?) AND access_id = ?', users, access.id])
       if num_p < access.limit
         UserAccess.create(:user => self, :access => access)
       else
         return "You have exceeded the maximum number of alotted permissions"
       end
     end
   end
 end

I would like to add also specs before refactoring. I added first one. How should looks like others?

  describe "#add_permission" do
    before do
      @permission = create(:permission)
      @user = create(:user)
    end

    it "allow create UserPermission" do
      expect {
        @user.add_permission(@permission)
      }.to change {
        UserPermission.count
      }.by(1)
    end
  end

Answer 1

Here is how I would do it.

Make the check on the Access more like an initial assertion, and raise an error if that happens.

Make a new method to check for an existing user access – that seems reusable, and more readable.

Then, the company limit is more like a validation to me, move this to the UserAccess class as a custom validation.

class User

  has_many :accesses, :class_name=>'UserAccess'

  def add_access(access)
    raise "Can only add a Access: #{access.inspect}" unless access.instance_of?(Access)

    if has_access?(access)
      logger.debug("User #{self.inspect} already has the access #{access}")
      return false
    end

    accesses.create(:access => access)
  end

  def has_access?(access)
    accesses.find(:first, :conditions => {:access_id=> access.id})
  end

end

class UserAccess

  validate :below_company_limit

  def below_company_limit
    return true unless company
    company_user_ids = company.users.map{|u| u.id unless u.blank?}.compact
    access_count = UserAccess.count(:conditions => ['user_id IN (?) AND access_id = ?', company_user_ids, access.id])
    access_count < access.limit
  end

end