6. Modules and Mixins

Activity 6.01: Implementing Categories on the Voting Application Program

Solution

1. We'll begin by first using the code from the previous chapter and writing some tests.
2. Write a new test for VotingMachine to add a category:

   require "minitest/autorun"
   require 'minitest/stub_any_instance'
   require_relative "../models/voting_machine"
   class TestVotingMachine < Minitest::Test
     def test_add_category
       machine = VotingMachine.new(1, 1)
       machine.add_category("TestCategory")
       assert_equal machine.categories, ["TestCategory"]
       machine.add_category("TestCategory2")
       assert_equal machine.categories, ["TestCategory", "TestCategory2"]
       machine.add_category("TestCategory")
       assert_equal machine.categories...