Secrets of Testing Rails 5 apps

Talk given at Rails Pacific

Transcript

1. ֦অ
2. Prathamesh Sonpatki @_cha1tanya
4. Pune, India
5. @deccanrubyconf
6. papercall.io/ deccanrubyconf-2016
7. deccanrubyconf.com
8. Rails issues team
11. CodeTriage.com
12. Stickers collector
13. Stickers
14. Do you have stickers?
15. T-Shirts are fine too
16. I have something!
17. Do you have a favourite Open source maintainer?
18. Say Thanks!
19. @Schneems
20. Secrets of Testing Rails 5 apps
21. Delete tests
22. Delete tests
23. Secrets of Testing Rails 5 apps
24. Running tests
25. rake test Rails 4
26. Test output matters!
27. Test output matters!
28. Test output matters!
29. $ be rake test test/controllers/users_controller_test.rb Run options: --seed 8322 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 Rails 4
30. $ be rake test test/controllers/users_controller_test.rb Run options: --seed 8322 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 Rails 4
31. $ be rake test test/controllers/users_controller_test.rb:9 Rails 4
32. $ 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) Rails 4
33. Show me what failed?
34. Show me quickly!
35. Which tests were slow?
37. But it’s possible
38. Because minitest!
39. Discoverability ?
41. Documentation ?
42. $ bin/rake -T test rake test # Runs all tests in test folder rake test:all # Run tests quickly by merging all types and not resetting db rake test:all:db # Run tests quickly, but also reset db rake test:db # Run tests quickly, but also reset db Rails 4
43. $ rails Usage: rails COMMAND [ARGS] The most common rails commands are: generate Generate new code (short-cut alias: "g") console Start the Rails console (short-cut alias: "c") server Start the Rails server (short-cut alias: "s") dbconsole Start a console for the database specified in config/database.yml (short-cut alias: "db") new Create a new Rails application. "rails new my_app" creates a new application called MyApp in "./my_app" In addition to those, there are: destroy Undo code generated with "generate" (short-cut alias: "d") plugin new Generates skeleton for developing a Rails plugin runner Run a piece of code in the application environment (short-cut alias: "r") All commands can be run with -h (or --help) for more information. Rails 4
44. Many libraries trying to solve same problem
47. Let’s make runing tests in Rails great again
48. https://github.com/rails/rails/pull/18596
49. Test Runner
50. bin/rails test Rails 5
51. $ 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
52. Documentation
53. $ 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 Rails 5
54. $ 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 Rails 5
55. $ 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 Rails 5
56. Improved filtering of tests
57. Rerun snippets
58. $ 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 Rails 5
59. $ 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 Rails 5
60. Running multiple tests
61. $ bin/rails test test/models/user_test.rb:27 test/models/ post_test.rb:42 Rails 5
62. $ bin/rails test test/controllers test/integration Rails 5
63. Improved reporting of failures
64. Fail fast
65. Backtrace
66. Deferred output
67. Colored output
68. $ 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 ✨ Rails 5
69. Powered by Minitest 5
70. Rails minitest plugin + Custom reporter
71. Inspirations
72. RSpec mintiest-reporters maxitest m and others &
74. ✅Durian ✅ Stinky tofu ✅ Other food that can't fit in
75. Writing tests
76. Unit tests Functional tests Integration tests
77. Unit tests Functional tests Integration tests
78. Controller tests
79. What to test in a controller test
80. req —> res
81. req —> res
82. 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
83. 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
84. 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
85. req —> current state
86. Easy
87. But they Lie
88. class ArticlesControllerTest < ActionController::TestCase test "should create article" do assert_difference('Article.count') do assert assigns(:article) post :create, article: { title: @article.title } end assert_redirected_to article_path(assigns(:article)) end end Rails 4
89. Integration tests
90. class ArticlesIntegrationTest < 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
91. Almost same as controller test
92. And it’s close to real world
94. Slow!!
95. Integration controller tests in Rails 5
96. require 'test_helper' class UsersControllerTest < ActionDispatch::IntegrationTest setup do @user = users(:one) end test "should get index" do get users_url assert_response :success end test "should get new" do get new_user_url assert_response :success end test "should create user" do assert_difference('User.count') do post users_url, params: { user: { name: @user.name } } end assert_redirected_to user_path(User.last) end end Rails 5
97. Functional controller tests soft deprecated
98. Old functional tests will continue to work
99. ActionController:: TestCase
100. Might be extracted to a gem in Rails 5.1
101. Implications
102. class ArticlesControllerTest < ActionController::TestCase setup do john = users(:john) session[:user_id] = john.id end end Rails 4
103. class ArticlesControllerTest < ActionController::TestCase setup do john = users(:john) session[:user_id] = john.id end end Rails 4
104. class ArticlesControllerTest < ActionDispatch::IntegrationTest setup do john = users(:john) post login_url, params: {} end end Rails 5
105. class ArticlesControllerTest < ActionDispatch::IntegrationTest setup do john = users(:john) post login_url, params: {} end end Rails 5
106. class ArticlesControllerTest < ActionController::TestCase test ‘index’ do @request.headers["Accept"] = "text/plain, text/html” get :index end end Rails 4
107. class ArticlesControllerTest < ActionDispatch::IntegrationTest test ‘index’ do @request.headers["Accept"] = "text/plain, text/html” get :index end end Rails 4
108. class ArticlesControllerTest < ActionDispatch::IntegrationTest test ‘index’ do @request.headers["Accept"] = "text/plain, text/html” get :index end end # NoMethodError: undefined method `headers' for nil:NilClass Rails 5
109. class ArticlesControllerTest < ActionDispatch::IntegrationTest test ‘index’ do get :index, headers: { accept: "text/plain, text/html” } end end Rails 5
110. Controller tests == Integration tests Rails 5
111. What not to test in a controller test?
112. Don’t test controller internals
113. test "repos" do get :index assert_response :success, 'successfully renders index' assert_not_nil assigns(:repos), 'assigns to repos' assert_not_nil assigns(:repos_subs), 'assigns to repos_subs' assert_template :index, 'render index template' end Rails 4
114. test "repos" do get :index assert_response :success, 'successfully renders index' assert_not_nil assigns(:repos), 'assigns to repos' assert_not_nil assigns(:repos_subs), 'assigns to repos_subs' assert_template :index, 'render index template' end Rails 4
115. test "repos" do get :index assert_response :success, 'successfully renders index' assert_not_nil assigns(:repos), 'assigns to repos' assert_not_nil assigns(:repos_subs), 'assigns to repos_subs' assert_template :index, 'render index template' end Rails 4
116. def index @repos = Repo.all @repo_subs = Repo.first.repo_subs end Rails 4
117. Scratching the surface
118. test "repos" do get :index assert_response :success, 'successfully renders index' assert_select ".repo-item-title", text: 'issue_triage_sandbox' end Rails 5
119. test "repos" do get :index assert_response :success, 'successfully renders index' assert_select ".repo-item-title", text: 'issue_triage_sandbox' end #=> Repo.first.name = ‘issue_triage_sandbox’ Rails 5
120. gem ‘rails-dom-testing’
121. Not just testing controller action in isolation
122. End to end testing
123. Controller View interface
124. Controller View interface
125. Just an implementation detail
126. Deprecated assert_template assigns
127. BUT
128. Testing controller isolated from views
129. gem ‘rails-controller-testing’
130. Testing Rails 5 apps
131. End to end testing
132. We should talk more about it
133. Much more than this
134. Want to know more about Rails 5?
135. Rails 5 Blog Series blog.bigbinary.com /categories/Rails-5
136. This Week in Rails rails-weekly. ongoodbits.com
137. 拽拽 @_cha1tanya