You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: abstract_recurrence_pattern_test.rb
    path of file: ./repos/tracks/test/models/recurring_todos
    
    the code of the file until where you have to start completion: require 'test_helper'

module RecurringTodos

  class AbstractRecurrencePatternTest < ActiveSupport::TestCase
    fixtures :users

    def setup
      super
      @admin = users(:admin_user)
    end

    def test_pattern_builds_from_existing_recurring_todo
      rt = @admin.recurring_todos.first

      pattern = rt.pattern
      assert pattern.is_a?(DailyRecurrencePattern), "recurring todo should have daily pattern"
    end

    def test_validation_o
    
    def test_validation_on_start_date
      attributes = {
        'weekly_every_x_week'        => 1,
        'weekly_return_monday'       => 'm',                 # weekly specific
        'recurring_show_always'      => false,
        'recurring_show_days_before' => 5,
        'start_from'                 => nil
      }
      pattern = create_recurring_todo(attributes)
      assert !pattern.valid?, "should be not valid because start_from is empty"

      attributes['start_from'] = Time.zone.now - 1.week
      pattern = create_recurring_todo(attributes)
      assert pattern.valid?, "should be valid: " + pattern.errors.full_messages.to_s
    end