Unit Test in Ruby on Rails by Minitest

1. v.1.0 2015.08.09 Hosang Jeon jhsbeat@gmail.com HOW TO TEST IN RUBY ON RAILS

2. • 코드 변경의 side effect를 초기에 파악할 수 있다... 등등의 일반적인 Unit Test의 필요성  + • Rails Way를 자연스럽게 익힐 수 있다. • 즉, Rails Way를 따르지 않은 방식은 테스트에서 문제가 발생한다. WHY IS UNIT TEST NECESSARY / SO IMPORTANT?

3. THINGS YOU SHOULD KNOW • 대부분의 레일스 애플리케이션은 데이터베이스와의 상호작용을 통해 동작하기 때문에 테스트 역시 데이터베이스를 필요로 한다. • 이러한 이유로 효과적인 테스트를 수행하기 위해서는 어떻게 데이터베이스를 세팅하고 샘플 데이터를 집어넣는 지에 대해서 이해할 필요가 있다. • 테스트를 위한 데이터베이스와 개발을 위한 데이터베이스를 함께 사용하는 경우 샘플 데 이터가 개발용 데이터를 망칠 수 있기 때문에 테스트용 데이터베이스를 별도로 두는 것 이 안전하다. 두어야만 한다.

4. test/ 테스트 관련 파일들의 루트 디렉토리 models/ 모델관련 테스트 클래스들이 있는 디렉토리 controllers/ 컨트롤러관련 테스트 클래스들이 있는 디렉토리 integrations/ 여러개의 컨트롤러와 연관된 테스트 클래스들이 있는 디렉토리 helpers/ 헬퍼관련 테스트 클래스들이 있는 디렉토리 mailers/ 메일러관련 테스트 클래스들이 있는 디렉토리 fixtures/ 테스트 데이터들(fixture)이 들어있는 디렉토리 test_helper.rb 테스트와 관련된 기본 설정들을 담고 있는 클래스 DIRECTORIES FOR TEST IN RAILS

5. RAKE TASKS FOR RUNNING YOUR TEST TASKS DESCRIPTION rake test Runs all tests in the test folder. You can also simply run rake as Rails will run all the tests by default rake test:controllers Runs all the controller tests from test/controllers rake test:functionals Runs all the functional tests from test/controllers, test/mailers, and test/functional rake test:helpers Runs all the helper tests from test/helpers rake test:integration Runs all the integration tests from test/integration rake test:jobs Runs all the job tests from test/jobs rake test:mailers Runs all the mailer tests from test/mailers rake test:models Runs all the model tests from test/models rake test:units Runs all the unit tests from test/models, test/helpers, and test/unit rake test:db Runs all tests in the test folder and resets the db

6. 픽스쳐(Fixtures)란

7. 무엇인가? In software testing, a test fixture is a fixed state of the software under test used as a baseline for running tests; also known as the test context. https://en.wikipedia.org/wiki/Test_fixture#Software 테스트 픽서쳐란, 소프트웨어 테스트의 기준이 되는 고정된 상태값을 의미한다.

9. 무엇인가? • 샘플(테스트) 데이터를 멋있게 부르는 말 • YAML 로 작성되어 있음. • 일종의 ActiveRecord object 라고 생각하면 됨 • Fixture 파일명은 테이블의 이름과 반드시 일치해야 한다. david: name: David Heinemeier Hansson birthday: 1979-10-15 profession: Systems development steve: name: Steve Ross Kellock birthday: 1974-09-27

10. # In fixtures/categories.yml about: name: About # In fixtures/articles.yml one: title: Welcome to Rails! body: Hello world! category: about 픽스쳐(Fixtures)란

11. 무엇인가? • 만약, fixture 안에서 association을 정의해야 하는 경우 아래와 같이   reference node 를 지정해 주면 됨. reference node belongs_to

13. 무엇인가? • 만약, 픽스쳐파일의 확장자 끝에 .erb를 붙여주면 루비코드를 사용할 수 있다. • 루비코드를 이용하면 많은 양의 테스트 데이터를 손쉽게 생성할 수 있다. % 1000.times do |n| % user_%= n %: username: %= user#{n} % email: %= user#{n}@example.com % % end %

14. 픽스쳐의

15. 동작방식 • Rails는 test/fixtures 하위에 있는 모든 픽스쳐들을 세 단계에 걸쳐 로딩한다. 1. 픽스쳐에 해당하는 테이블의 기존 데이터를 삭제 한다. 2. 픽스쳐 데이터를 테이블에 로드 한다. 3. 픽스쳐 데이터에 직접 접근하고자 하는 경우에는 이를 변수에 덤프 한다. • 픽스쳐의 각 데이터는 아래와 같이 직접 접근이 가능하다. accessed by node name # In fixtures/users.yml david: name: David Heinemeier Hansson birthday: 1979-10-15 profession: Systems development # In test class users(:david) users(:david).id

16. UNIT

17. TEST

18. for

19. YOUR

20. MODELS

21. require 'test_helper' class ArticleTest ActiveSupport::TestCase # test the truth do # assert true # end end DEFAULT

22. TEST

23. CASE

24. generated

25. by

26. Rails • Minitest::Test 를 상속한 클래스에서는 test_ 로 시작하는 모든 메서드를 자동적으 로 테스트케이스로 인식하여 테스트 수행시 자동적으로 수행하게 된다. • Rails는 여기에 test 라는 이름의 메서드를 추가하였는데, 이 메서드는 [테스트 명]과 [블록] 을 받아서 이를 일반적인 Minitest::Unit으로 생성해 준다. 즉, 위의 코드에서 test “the truth” do... 는 실제로 아래와 같은 메서드를 생성한다. test_helper.rb : 모든 테스트에 공통적으로 적용되는 기본 설정을 정의하는 클래스 Minitest::Test ActiveSupport::TestCase ArticleTest def test_the_truth assert true end

27. MODEL

28. TEST

29. IN

30. ACTION

31. require test_helper    class ProductTest ActiveSupport::TestCase  test product price must be positive do  product = Product.new(title: My Book Title,  description: yyy,  image_url: zzz.jpg)  product.price = -1  assert product.invalid?, negative price of a product must be invalid.  assert product.errors.has_key?(:price), an invalid product must have an error    product.price = 0  assert product.invalid?, negative price of a product must be invalid.  assert product.errors.has_key?(:price), an invalid product must have an error    product.price = 1  assert product.valid?, positive price of a product must be valid.  assert_empty product.errors, a valid product must have no error  end  end SIMPLE

32. MODEL

33. TEST

34. CASE Product의 가격이 항상 0보다 커야함을 테스트. 가격이 -1, 0인 경우 모델은 invalid 해야 하고, error가 존재해야 함. 가격이 1인 경우 모델은 valid 해야 하고, error가 nil이어야 함. assertion의 두번재 파라미터는 해당 assertion이 실패했을 때 보여줄 메시지이다.

35. $ rake test test/models/product_test.rb Run options: --seed 29214 # Running: E Finished in 0.042839s, 23.3433 runs/s, 0.0000 assertions/s. 1) Error: ProductTest#test_product_price_must_be_positive: NameError: uninitialized constant ProductTest::Product test/models/product_test.rb:5:in `block in class:ProductTest' 1 runs, 0 assertions, 0 failures, 1 errors, 0 skips TEST

36. CASE

37. 실행

38. #1

40. Error 테스트 실행 Product 모델이 없기 때문에 Error 발생 1개의 Test Case가 실행되어 1개의 Error가 발생

41. $ rails g model Product title:string description:text image_url:string price:integer invoke active_record create db/migrate/20150814072826_create_products.rb create app/models/product.rb invoke test_unit conflict test/models/product_test.rb Overwrite /Users/hosang/01.work/git/jobplanet/test/models/product_test.rb? (enter h for help) [Ynaqdh] n skip test/models/product_test.rb create test/fixtures/products.yml $ RAILS_ENV=test rake db:migrate TEST

42. CASE

43. 실행

44. #1

46. FIX Product 모델 생성 기존에 이미 product_test.rb 파일이 존재하기 때문에 conflict 발생한다. n 키를 눌러서 skip db migration 실행

47. $ rake test test/models/product_test.rb Run options: --seed 61999 # Running: F Finished in 0.050778s, 19.6935 runs/s, 19.6935 assertions/s. 1) Failure: ProductTest#test_product_price_must_be_positive [/Users/ hosang/01.work/git/jobplanet/test/models/product_test.rb:9]: negative price of a product must be invalid. 1 runs, 1 assertions, 1 failures, 0 errors, 0 skips TEST

48. CASE

49. 실행

50. #2

52. Failure 테스트 재실행 음수의 가격이 갖는 모델이 invalid 하다고 판단되지 않아서 assertion 실패 1개의 Test Case가 실행되어 1개의 assertion 가운데 1 개가 실패

53. TEST

54. CASE

55. 실행

56. #2

58. FIX Product 모델에 :price attribute에 validation을 추가 class Product ActiveRecord::Base  validates_numericality_of :price, greater_than: 0  end

59. $ rake test test/models/product_test.rb [DEPRECATION] Ahoy subscribers are deprecated Run options: --seed 47932 # Running: . Finished in 0.235739s, 4.2420 runs/s, 29.6939 assertions/s. 1 runs, 7 assertions, 0 failures, 0 errors, 0 skips TEST

60. CASE

61. 실행

62. #3

64. Pass 테스트 재실행 1개의 Test Case가 실행되어 총 7개의 assertion이 실패 없이 모두 수행됨.

66. CASE

67. 실행

68. #3

70. Pass 테스트 재실행 1개의 Test Case가 실행되어 총 7개의 assertion이 실패 없이 모두 수행됨. WAIT!!

77. ASSERTIONS?

92. WHY?

94. CASE

95. 실행

96. #3

98. Pass 테스트 재실행 1개의 Test Case가 실행되어 총 7개의 assertion이 실패 없이 모두 수행됨. def assert_empty obj, msg = nil  msg = message(msg) { Expected #{mu_pp(obj)} to be empty }  assert_respond_to obj, :empty?  assert obj.empty?, msg  end assert_empty는

99. 내부적으로

100. 2개의

101. assertion을

102. 실행함. http://stackoverflow.com/questions/32005317/minitesttest-in-ruby-on-rails- produces-more-assertions-than-i-expect/32005942#32005942

103. FUNCTIONAL

104. TEST

105. for

106. YOUR

107. CONTROLLERS

108. DEFAULT

109. CONTROLLER

110. TEST

111. CASE

112. generated

113. by

114. Rails test_helper.rb : 모든 테스트에 공통적으로 적용되는 기본 설정을 정의하는 클래스 Minitest::Test ActiveSupport::TestCase ArticleTest require 'test_helper'    class ArticlesControllerTest ActionController::TestCase  setup do  @article = articles(:one)  end    test should get index do  get :index  assert_response :success  end  end Because we redirect the route unless user has logged in. If you have a authentication checking filter using Devise before this action, then this test case will be failed. WYH?

115. SIMPLE

116. CONTROLLER

117. TEST

118. CASE 3) WORKS FINE ENV['RAILS_ENV'] ||= 'test'  require File.expand_path('../../config/environment', __FILE__)  require 'rails/test_help'    class ActiveSupport::TestCase  # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order.  fixtures :all    # Add more helper methods to be used by all tests here...  end    # https://github.com/plataformatec/devise  class ActionController::TestCase  include Devise::TestHelpers  end require 'test_helper'    class ArticlesControllerTest ActionController::TestCase  setup do  @article = articles(:one)  sign_in users(:one)  end    test should get index do  get :index  assert_response :success  end  end 1) Include Devise Helper in test_helper.rb file 2) Sign In

119. INTEGRATION

120. TEST

121. $ bin/rails generate minitest:feature CanSignupNewUser create test/features/can_signup_new_user_test.rb Integration

122. Test

123. 는

124. rails

125. 가

126. 자동

127. 생성

128. 해주지

129. 않기

130. 때문에

131. 따로

132. 만들어야

133. 함 test/features 디렉터리에 새로운 feature test case 가 생성 됨. Minitest

134. 의

135. default

136. integration

137. test도

138. 있으나,

139. 여기에서는

140. Capybara를

141. 이용함. ENV['RAILS_ENV'] ||= 'test'  require File.expand_path('../../config/environment', __FILE__)  require 'rails/test_help'  require minitest/rails/capybara    class ActiveSupport::TestCase  # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order.  fixtures :all    # Add more helper methods to be used by all tests here...  end    # https://github.com/plataformatec/devise  class ActionController::TestCase  include Devise::TestHelpers  end    # https://github.com/blowmage/minitest-rails-capybara  class ActionDispatch::IntegrationTest  include Capybara::DSL  include Capybara::Assertions  end 1) Include Capybara

142. SIGN

143. UP

144. SCENARIO

145. TEST require test_helper    class SignupTest Capybara::Rails::TestCase  test can signup with email do  # 1. Visit landing page  # 2. enter email and password (twice)  # 3. click register button  # 4. Success   end  end WRITE SCENARIO

146. SIGN

147. UP

148. SCENARIO

149. TEST require test_helper    class SignupTest Capybara::Rails::TestCase  test can signup with email do  # 1. Visit landing page  visit root_path    # 2. enter email and password (twice)  page.fill_in 'user[email]', with: #{Time.now.to_i}@test.com  page.fill_in 'user[password]', with: qwer1234  page.fill_in 'user[password_confirmation]', with: qwer1234    # 3. click register button  page.find(‘#btn_sign_up').click    # 4. Success  assert_equal 200, page.status_code  end  end WRITE TEST CODES 참고: Capybara TestCase 에서는 Rails Specific assert 를 사용할 수 없음.

150. AVAILABLE ASSERTIONS

151. AVAILABLE ASSERTIONS CAN BE USED WITH MINITEST (1/3) ASSERTIONS PURPOSE assert( test, [msg] ) Ensures that test is true. assert_not( test, [msg] ) Ensures that test is false. assert_equal( expected, actual, [msg] ) Ensures that expected == actual is true. assert_not_equal( expected, actual, [msg] ) Ensures that expected != actual is true. assert_same( expected, actual, [msg] ) Ensures that expected.equal?(actual) is true. assert_not_same( expected, actual, [msg] ) Ensures that expected.equal?(actual) is false. assert_nil( obj, [msg] ) Ensures that obj.nil? is true. assert_not_nil( obj, [msg] ) Ensures that obj.nil? is false. assert_empty( obj, [msg] ) Ensures that obj is empty?. assert_not_empty( obj, [msg] ) Ensures that obj is not empty?. assert_match( regexp, string, [msg] ) Ensures that a string matches the regular expression. assert_no_match( regexp, string, [msg] ) Ensures that a string doesn't match the regular expression. assert_includes( collection, obj, [msg] ) Ensures that obj is in collection. assert_not_includes( collection, obj, [msg] ) Ensures that obj is not in collection. assert_in_delta( expecting, actual, [delta], [msg] ) Ensures that the numbers expected and actual are within delta of each other. assert_not_in_delta( expecting, actual, [delta], [msg] ) Ensures that the numbers expected and actual are not within delta of each other.

152. AVAILABLE ASSERTIONS CAN BE USED WITH MINITEST (2/3) ASSERTIONS PURPOSE assert_throws( symbol, [msg] ) { block } Ensures that the given block throws the symbol. assert_raises( exception1, exception2, ... ) { block } Ensures that the given block raises one of the given exceptions. assert_nothing_raised( exception1, exception2, ... ) { block } Ensures that the given block doesn't raise one of the given exceptions. assert_instance_of( class, obj, [msg] ) Ensures that obj is an instance of class. assert_not_instance_of( class, obj, [msg] ) Ensures that obj is not an instance of class. assert_kind_of( class, obj, [msg] ) Ensures that obj is or descends from class. assert_not_kind_of( class, obj, [msg] ) Ensures that obj is not an instance of class and is not descending from it. assert_respond_to( obj, symbol, [msg] ) Ensures that obj responds to symbol. assert_not_respond_to( obj, symbol, [msg] ) Ensures that obj does not respond to symbol. assert_operator( obj1, operator, [obj2], [msg] ) Ensures that obj1.operator(obj2) is true. assert_not_operator( obj1, operator, [obj2], [msg] ) Ensures that obj1.operator(obj2) is false. assert_predicate ( obj, predicate, [msg] ) Ensures that obj.predicate is true, e.g. assert_predicate str, :empty? assert_not_predicate ( obj, predicate, [msg] ) Ensures that obj.predicate is false, e.g. assert_not_predicate str, :empty? assert_send( array, [msg] ) Ensures that executing the method listed in array[1] on the object in array[0] with the parameters of array[2 and up] is true. This one is weird eh? flunk( [msg] ) Ensures failure. This is useful to explicitly mark a test that isn't finished yet.

153. AVAILABLE ASSERTIONS CAN BE USED WITH MINITEST (3/3) RAILS SPECIFIC ASSERTIONS PURPOSE assert_difference(expressions, difference = 1, message = nil) {...} Test numeric difference between the return value of an expression as a result of what is evaluated in the yielded block. assert_no_difference(expressions, message = nil, amp;block) Asserts that the numeric result of evaluating an expression is not changed before and after invoking the passed in block. assert_recognizes(expected_options, path, extras={}, message=nil) Asserts that the routing of the given path was handled correctly and that the parsed options (given in the expected_options hash) match path. Basically, it asserts that assert_generates(expected_path, options, defaults={}, extras = {}, message=nil) Asserts that the provided options can be used to generate the provided path. This is the inverse of assert_recognizes. The extras parameter is used to tell the request the assert_response(type, message = nil) Asserts that the response comes with a specific status code. You can specify :success to indicate 200-299, :redirectto indicate 300-399, :missing to assert_redirected_to(options = {}, message=nil) Assert that the redirection options passed in match those of the redirect called in the latest action. This match can be partial, such that assert_template(expected = nil, message=nil) Asserts that the request was rendered with the appropriate template file. assert_difference(expressions, difference = 1, message = nil) {...} Test numeric difference between the return value of an expression as a result of what is evaluated in the yielded block. assert_no_difference(expressions, message = nil, amp;block) Asserts that the numeric result of evaluating an expression is not changed before and after invoking the passed in block. assert_recognizes(expected_options, path, extras={}, message=nil) Asserts that the routing of the given path was handled correctly and that the parsed options (given in the expected_options hash) match path. Basically, it asserts that assert_generates(expected_path, options, defaults={}, extras = {}, message=nil) Asserts that the provided options can be used to generate the provided path. This is the inverse of assert_recognizes. The extras parameter is used to tell the request the assert_response(type, message = nil) Asserts that the response comes with a specific status code. You can specify :success to indicate 200-299, :redirectto indicate 300-399, :missing to assert_redirected_to(options = {}, message=nil) Assert that the redirection options passed in match those of the redirect called in the latest action. This match can be partial, such that assert_template(expected = nil, message=nil) Asserts that the request was rendered with the appropriate template file.

154. REFERENCES A Guide to Testing Rails Applications:   http://guides.rubyonrails.org/testing.html   Capybara:   https://github.com/jnicklas/capybara

155. THANKS FOR READING Hosang Jeon jhsbeat@gmail.com hosangjeon.com guruble.com

Unit Test in Ruby on Rails by Minitest

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