Secrets of testing Rails 5 apps

RailsConf 2016 talk

Transcript

1. Secrets of Testing Rails 5 apps
2. Prathamesh Sonpatki @_cha1tanya
4. Stickers
5. Stickers
6. Do you have stickers?
7. CodeTriage.com
8. Rails 5 Yay!
9. So many changes
10. the way we test code
11. the way we run tests
12. the way we write tests
13. Testing Rails 5 apps
14. Running tests
15. Recap
16. rake test Rails 4.x
17. rake test:controllers Rails 4.x
18. Limitations
19. $ be rake test test/controllers/users_controller_test.rb Run options: --seed 8322 # Running: F Finished in 0.621790s, 1.6083 runs/s, 1.6083 assertions/s. 1) Failure: UsersControllerTest#test_contact_info_successfully_renders_page [railsconf_talk/test/controllers/users_controller_test.rb:9]: #<Proc:0x007fd76ce55b50@/railsconf_talk/test/controllers/ users_controller_test.rb:9 (lambda)> didn't change by 1. Expected: 20 Actual: 19 1 runs, 1 assertions, 1 failures, 0 errors, 0 skips
20. $ be rake test test/controllers/users_controller_test.rb:9 rake aborted! Don't know how to build task 'test/controllers/users_controller_test.rb:9' (See full trace by running task with --trace)
21. Test Runner
22. bin/rails test Rails 5
23. $ bin/rails test Run options: --seed 34502 # Running: ....... Finished in 2.437723s, 2.8715 runs/s, 4.9226 assertions/s. 7 runs, 12 assertions, 0 failures, 0 errors, 0 skips Rails 5
24. Rerun snippets
25. $ bin/rails test Run options: --seed 44837 # Running: .....F Failure: PostsControllerTest#test_should_create_post [railsconf_talk/test/controllers/ posts_controller_test.rb:19]: "Post.count" didn't change by 2. Expected: 4 Actual: 3 bin/rails test test/controllers/posts_controller_test.rb:18 . Finished in 0.622410s, 11.2466 runs/s, 16.0666 assertions/s. 7 runs, 10 assertions, 1 failures, 0 errors, 0 skips
26. $ bin/rails test Run options: --seed 44837 # Running: .....F Failure: PostsControllerTest#test_should_create_post [railsconf_talk/test/controllers/ posts_controller_test.rb:19]: "Post.count" didn't change by 2. Expected: 4 Actual: 3 bin/rails test test/controllers/posts_controller_test.rb:18 . Finished in 0.622410s, 11.2466 runs/s, 16.0666 assertions/s. 7 runs, 10 assertions, 1 failures, 0 errors, 0 skips
27. $ bin/rails test test/controllers/posts_controller_test.rb:18 Run options: --seed 5361 # Running: F Failure: PostsControllerTest#test_should_create_post [railsconf_talk/test/controllers/ posts_controller_test.rb:19]: "Post.count" didn't change by 2. Expected: 4 Actual: 3 bin/rails test test/controllers/posts_controller_test.rb:18 Finished in 0.456947s, 2.1884 runs/s, 2.1884 assertions/s. 1 runs, 1 assertions, 1 failures, 0 errors, 0 skips
28. Documentation
29. $ bin/rails t -h minitest options: -h, --help Display this help. -s, --seed SEED Sets random seed. Also via env. Eg: SEED=n rake -v, --verbose Verbose. Show progress processing files. -n, --name PATTERN Filter run on /regexp/ or string. Known extensions: rails, pride Usage: bin/rails test [options] [files or directories] You can run a single test by appending a line number to a filename: bin/rails test test/models/user_test.rb:27 You can run multiple files and directories at the same time: bin/rails test test/controllers test/integration/login_test.rb By default test failures and errors are reported inline during a run. Rails options: -e, --environment ENV Run tests in the ENV environment -b, --backtrace Show the complete backtrace -d, --defer-output Output test failures and errors after the test run -f, --fail-fast Abort test run on first failure or error -c, --[no-]color Enable color in the output
30. Running multiple tests
31. $ bin/rails test test/models/user_test.rb:27 test/models/post_test.rb:42
32. $ bin/rails test test/controllers test/integration
33. $ bin/rails test test/models/user_test.rb:27:89
34. Backtrace
35. $ BACKTRACE=1 bin/rake test test/models/post_test.rb Rails 4.x
36. $ bin/rails test test/models/post_test.rb -b Rails 5
37. Fail fast
38. $ bin/rails test -f Rails 5
39. $ bin/rails t -f Run options: -f --seed 4299 # Running: ...F Failure: PostsControllerTest#test_should_create_post [railsconf_talk/test/controllers/ posts_controller_test.rb:19]: "Post.count" didn't change by 2. Expected: 4 Actual: 3 bin/rails test test/controllers/posts_controller_test.rb:18 Interrupted. Exiting... Finished in 0.677870s, 5.9008 runs/s, 7.3760 assertions/s. 4 runs, 5 assertions, 1 failures, 0 errors, 0 skips
40. Colored output
42. $ bin/rails t Run options: --seed 16545 # Running: ...F Failure: PostsControllerTest#test_should_create_post [/Users/prathamesh/Projects/ reproductions/railsconf_talk/test/controllers/posts_controller_test.rb: 19]: "Post.count" didn't change by 2. Expected: 4 Actual: 3 ✅
43. Minitest 5
44. Rails plugin + Custom reporter
45. Inspirations
46. RSpec mintiest-reporters maxitest and Others
47. Controller tests
48. class ArticlesControllerTest < ActionController::TestCase test "should create article" do assert_difference('Article.count') do post :create, article: { title: @article.title } end assert_redirected_to article_path(assigns(:article)) end end Rails 4.x
49. class ArticlesControllerTest < ActionDispatch::IntegrationTest test "should create article" do assert_difference('Article.count') do post articles_url, params: { article: { title: @article.title } } end assert_redirected_to article_path(Article.last) end end Rails 5
50. class ArticlesControllerTest < ActionDispatch::IntegrationTest test "should create article" do assert_difference('Article.count') do post articles_url, params: { article: { title: @article.title } } end assert_redirected_to article_path(Article.last) end end Rails 5
51. class ArticlesControllerTest < ActionDispatch::IntegrationTest test "should create article" do assert_difference('Article.count') do post articles_url, params: { article: { title: @article.title } } end assert_redirected_to article_path(Article.last) end end Rails 5
52. class ArticlesControllerTest < ActionDispatch::IntegrationTest test "should create article" do assert_difference('Article.count') do post articles_url, params: { article: { title: @article.title } } end assert_redirected_to article_path(Article.last) end end Rails 5
53. Why?
54. class ArticlesControllerTest < ActionController::TestCase test "should create article" do assert_difference('Article.count') do post :create, article: { title: @article.title } end assert_redirected_to article_path(assigns(:article)) end end Rails 4.x
55. class ArticlesControllerTest < ActionDispatch::IntegrationTest test "should create article" do assert_difference('Article.count') do post articles_url, params: { article: { title: @article.title } } end assert_redirected_to article_path(Article.last) end end Rails 5
56. Almost same!
57. Integration tests are slow Rails 4
58. Integration tests were slow Rails 5
59. @eileencodes
60. Close to real world
61. Rails 5 generates integration controller tests
62. Old apps?
63. Backward compatible
64. ActionController::TestCase gem Rails 5.1
65. Implications
66. class ArticlesControllerTest < ActionController::TestCase setup do john = users(:john) session[:user_id] = john.id end end Rails 4.x
67. class ArticlesControllerTest < ActionDispatch::IntegrationTest setup do post login_url, params: { .. } end end Rails 5
68. class ArticlesControllerTest < ActionController::TestCase test ‘index’ do @request.headers["Accept"] = "text/plain, text/html” get :index end end Rails 4.x
69. class ArticlesControllerTest < ActionDispatch::IntegrationTest test ‘index’ do get articles_url, params: { .. }, headers: {} end end Rails 5
70. What do we actually test?
71. class ArticlesControllerTest < ActionController::TestCase test "should create article" do assert_difference('Article.count') do post :create, article: { title: @article.title } end assert_redirected_to article_path(assigns(:article)) end end Rails 4.x
72. :action Rails 4.x
73. instance variables Rails 4.x
74. status code Rails 4.x
75. template Rails 4.x
76. HTML Rails 4.x
77. class ArticlesControllerTest < ActionDispatch::IntegrationTest test "should create article" do assert_difference('Article.count') do post articles_url, params: { article: { title: @article.title } } end assert_redirected_to article_path(Article.last) end end Rails 5
78. request Rails 5
79. status code Rails 5
80. HTML Rails 5
81. But.. Rails 5
82. can’t test instance variables Rails 5
83. can’t test which template rendered Rails 5
84. assert_template Deprecated assigns Rails 5
85. Controller internals Not recommended Rails 5
86. test actual HTML Recommended Rails 5
87. assert_select Recommended Rails 5
88. gem ‘rails-dom-testing’ Recommended Rails 5
89. Not just testing controller action Rails 5
90. Controller + View Rails 5
91. There is a space between controller and views
92. Don’t go there! Rails 5
93. Controller View interface Rails 5
94. Just an implementation detail Rails 5
95. BUT
96. Why do we test controller internals
97. Correct template gets rendered
98. Verify correct data gets passed to views
99. Instance variables
100. THE way to send data to views
101. The unwritten contract
102. Interface testing
103. Testing controllers the old way
104. Isolated from views
105. No longer recommended
106. But sometimes needed
107. Controller via engine
108. gem ‘rails-controller-testing’
109. Testing API apps
110. require 'test_helper' class ApiTest < ActionDispatch::IntegrationTest test 'creates articles' do assert_difference -> { Article.count } do post articles_path, params: { article: { title: 'Ahoy!' } } end end end
111. JSON or XML requests
112. require 'test_helper' class ApiTest < ActionDispatch::IntegrationTest test 'creates articles' do assert_difference -> { Article.count } do post articles_path(format: :json), params: { article: { title: 'Ahoy!' } }.to_json, headers: { 'Content-Type' => 'application/json' } end end end Rails 4.x
113. Request Encoding
114. `as` encoder
115. require 'test_helper' class ApiTest < ActionDispatch::IntegrationTest test 'creates articles' do assert_difference -> { Article.count } do post articles_path, params: { article: { title: 'Ahoy!' } }, as: :json end end end Rails 5
116. ActionDispatch::IntegrationTest.register_encoder
117. require 'test_helper' class ApiTest < ActionDispatch::IntegrationTest test 'creates articles' do assert_difference -> { Article.count } do post articles_path, params: { article: { title: 'Ahoy!' } }, as: :json end assert_equal({ 'id' => Article.last.id, 'title' => 'Ahoy!' }, parse_json(response.body)) end end Rails 4.x
118. Response parsing
119. response.parsed_body
120. require 'test_helper' class ApiTest < ActionDispatch::IntegrationTest test 'creates articles' do assert_difference -> { Article.count } do post articles_path, params: { article: { title: 'Ahoy!' } }, as: :json end assert_equal({ 'id' => Article.last.id, 'title' => 'Ahoy!' }, response.parsed_body) end end Rails 5
121. The other changes
122. Active Job Async adapter
123. Random test ordering
124. Fixtures
125. file_fixture
126. test/fixtures/files
127. file_fixture(“response.json”) #=> Pathname
128. file_fixture(“response.json”).read
129. file_fixture(“response.json”).size
130. ActiveSupport::TestCase.file_fixture_path
131. Custom AR classes with fixtures
132. class Post < ActiveRecord::Base self.table_name = 'records' has_many :comments end class Comment < ActiveRecord::Base belongs_to :post end
133. # records.yml # comments.yml
134. # test_helper.rb class ActiveSupport::TestCase set_fixture_class records: Post end
135. $ bin/rails db:schema:load
136. Metadata can be added in Rails 5
137. # records.yml _fixture: model_class: Post blurrgh: name: Rails 5 final release
138. Request methods
139. get post patch delete
140. class ProductsControllerTest < ActionController::TestCase def test_create post :create { product: { name: "FIFA" } } assert_response :success end end Rails 4.x
141. Positional arguments Rails 4.x
142. class ProductsControllerTest < ActionController::TestCase def test_create post :create { product: { name: "FIFA" } }, nil, { message: "Yay!" } assert_response :success end end Rails 4.x
143. class ProductsControllerTest < ActionController::TestCase def test_create post :create nil, nil, { message: "Yay!" } assert_response :success end end Rails 4.x
144. Keyword arguments Rails 5
145. Ruby 2.2.2+
146. class ProductsControllerTest < ActionDispatch::IntegrationTest def test_create post product_url, params: { product: { name: "FIFA" } } assert_response :success end end Rails 5
147. Old tests
148. ActionDispatch::ControllerTest #=> params flash session xhr
149. New tests
150. ActionDispatch::IntegrationTest #=> params env headers xhr
151. Testing Rails 5 apps
152. Better experience
153. More focus on end to end testing
154. Controller + View
155. Happy testing!
156. May the fourth
157. May the fifth
158. With Rails default test stack
160. RSpec and Rails 5 Justin Searls
161. Want to know more about Rails 5?
162. Rails 5 Blog Series http://blog.bigbinary.com/categories/ Rails%205
163. https://rails-weekly.ongoodbits.com/
164. RailsConf edition coming sooooooooooon!
165. 
 Thank You @_cha1tanya