Testing Primer (URUG presentation 7/12/2011)

list.rb

class List < ActiveRecord::Base
  belongs_to :user
  
  validates_presence_of :name
  validates_presence_of :user
end

list_test.rb

require 'test_helper'

class ListTest < ActiveSupport::TestCase

  setup do
    @valid_params = { :name => "Mike Moore",
                      :user => User.new }
  end

  test "is valid with valid params" do
    list = List.new @valid_params
    assert list.valid?
  end

  test "needs a name to be valid" do
    params = @valid_params.clone
    params.delete :name
    list = List.new params
    refute list.valid?
    assert list.errors[:name].include?("can't be blank")
  end

  test "needs a user to be valid" do
    params = @valid_params.clone
    params.delete :user
    list = List.new params
    refute list.valid?
    assert list.errors[:user].include?("can't be blank")
  end

end

task.rb

class Task < ActiveRecord::Base
  belongs_to :list
end

task_test.rb

require 'test_helper'

class TaskTest < ActiveSupport::TestCase
  # Replace this with your real tests.
  test "the truth" do
    assert true
  end
end

user.rb

class User < ActiveRecord::Base
  has_many :lists
  
  def list_names
    lists.map &:name
  end
end

user_test.rb

require 'test_helper'

class UserTest < ActiveSupport::TestCase

  setup do
    @user = User.new
  end

  test "user should call 'list_names' method and get the names of the lists the user owns" do
    @user.lists.build :name => "list 1"
    @user.lists.build :name => "list 2"
    @user.lists.build :name => "list 3"
    
    assert_equal ["list 1", "list 2", "list 3"],
                  @user.list_names
  end
  
  test "a user with only one list should only return that list name" do
    @user.lists.build :name => "list 1"
    
    assert_equal ["list 1"],
                  @user.list_names
  end
  
  test "a user with no lists should return an empty list" do
    assert_equal [],
                 @user.list_names
  end

end