Zero-confidence by Katrina Owen

Transcript

1. ................................. ................................. ................................. ................................. ............................ 467 tests, 0 failures, 0

   confidence Katrina Owen @kytrinyx JumpstartLab

2. Pointe •◀ .

3. ......F...

4. F F F F F F F F F

5. test results not implementation

6. results

7. command query separation . . . . . . .

   . . . . . . . . . . . ✂

8. returns a value, has no side effects query

9. has side effects, returns nil command

10. . . . . . . . . . .

    . . . . . . . ✂ command query

11. query @waiter.menu

12. command @bill.add(steak)

13. both ... it’s complicated

14. responsibility and collaboration

15. mock expectation

16. mock stub . . . . . . . .

    . . . . . . . . . ✂ assertion dumb value

17. who is responsible?

18. sender :message receiver outgoing incoming

19. incoming assert the state of the system

20. outgoing assert collaboration

21. rules of thumb

22. Query Incoming ?

23. Query Incoming assert return value

24. Query Command Incoming assert return value ?

25. Query Command Incoming assert return value assert side effects

26. Query Command Incoming Outgoing assert return value assert side effects

    ?

27. Query Command Incoming Outgoing assert return value assert side effects

    do not assert

28. Query Command Incoming Outgoing assert return value assert side effects

    do not assert ?

29. Query Command Incoming Outgoing assert return value assert side effects

    do not assert assert message sent

30. Query Command Incoming Private Outgoing assert return value assert side

    effects ? ? do not assert assert message sent

31. Query Command Incoming Private Outgoing assert return value assert side

    effects do not assert do not assert do not assert assert message sent

32. Query Command Incoming Private Outgoing assert return value assert side

    effects do not assert do not assert do not assert assert message sent

33. 1incoming query assert return value

34. 1incoming query assert return value assert_equal "...", @waiter.menu

35. assert direct, local side effects 2 incoming command

36. assert direct, local side effects 2 incoming command bill.add(steak)

37. assert direct, local side effects 2 bill.add(steak) assert_equal 32.90, bill.total

    incoming command

38. 3outgoing query do not assert

39. 3outgoing query do not assert chef.todays_special

40. assert message send 4 outgoing command

41. assert message send kitchen.expect(:order_up) 4 outgoing command

42. assert message send kitchen.expect(:order_up) waiter.i_would_like(:steak) 4 outgoing command

43. assert message send kitchen.expect(:order_up) waiter.i_would_like(:steak) kitchen.verify 4 outgoing command

44. assert message send 4 outgoing command kitchen.should_receive(:order_up) waiter.i_would_like(:steak)

45. 5private message do not assert

46. 5private message do not assert note_to_self(stuff)

47. unit test

48. unit test return values +

49. unit test return values + side effects +

50. unit test return values + side effects + critical interations

    +

51. unit test return values + side effects + critical interations

    + implementation details -

52. meet practice theory

53. github.com/it-agile codersdojo_client

54. @kata.generate 'ruby.rspec', 'prime'

55. code kata small coding exercise

56. @kata.generate 'ruby.rspec', 'prime'

57. @kata.generate 'ruby.rspec', 'prime'

58. @kata.generate 'ruby.rspec', 'prime'

59. @kata.generate 'ruby.rspec', 'prime'

60. class Prime def foo 'fixme' end end

61. class Prime def foo 'fixme' end end describe Prime do

    let(:prime) { Prime.new } its(:foo) { should == 'bar' } end
62. None

63. limit work in progress

64. Query Command Incoming Private Outgoing ✓

65. incoming command assert direct, local side effects

66. describe Scaffolder do it "generates the files and directories" it

    "replaces placeholders" end

67. describe Scaffolder do before (:each) do @shell = mock @shell.should_receive(:shell_extension).any_number_of_times.and_return

    "cmd" @shell.should_receive(:remove_command_name).any_number_of_times.and_return "del" @shell.should_receive(:path_separator).any_number_of_times.and_return ";" @shell.should_receive(:dir_separator).any_number_of_times.and_return "/" Scaffolder.should_receive(:current_file).any_number_of_times.and_return("aDir/lib/aFile.rb") @scaffolder = Scaffolder.new @shell end it "generates the files and directories" do @shell.should_receive(:real_dir_entries).with("aDir/templates/a.template").and_return ["a", "b"] @shell.should_receive(:cp_r).with "aDir/templates/a.template/a", "." @shell.should_receive(:file?).with("a").and_return false @shell.should_receive(:cp_r).with "aDir/templates/a.template/b", "." @shell.should_receive(:file?).with("b").and_return fals @scaffolder.scaffold "a.template", 'myKata' end it "replaces placeholders" do @shell.should_receive(:real_dir_entries).with("aDir/templates/a.template").and_return ["a", "README", "run-once.sh", "run-endless.sh"] @shell.should_receive(:cp_r).with "aDir/templates/a.template/a", "." @shell.should_receive(:file?).with("a").and_return false @shell.should_receive(:cp_r).with "aDir/templates/a.template/README", "." @shell.should_receive(:file?).with("README").and_return true @shell.should_receive(:read_file).with("README").and_return '%rm% %kata_file%\nb.%sh%\nc%:%d' @shell.should_receive(:write_file).with "README", 'del myKata\nb.cmd\nc;d' @shell.should_receive(:cp_r).with "aDir/templates/a.template/run-once.sh", "." @shell.should_receive(:file?).with("run-once.sh").and_return true @shell.should_receive(:read_file).with("run-once.sh").and_return "%rm% a\nb.%sh%\nc%:%d" @shell.should_receive(:write_file).with "run-once.sh", "del a\nb.cmd\nc;d" @shell.should_receive(:cp_r).with "aDir/templates/a.template/run-endless.sh", "." @shell.should_receive(:file?).with("run-endless.sh").and_return true @shell.should_receive(:read_file).with("run-endless.sh").and_return "%rm% a\nb.%sh%\nc%:%d" @shell.should_receive(:write_file).with "run-endless.sh", "del a\nb.cmd\nc;d" @scaffolder.scaffold "a.template", 'myKata' end end

68. describe Scaffolder do it "generates the files and directories" do

    @shell.should_receive(:real_dir_entries).with("aDir/templates/a.template").and @shell.should_receive(:cp_r).with "aDir/templates/a.template/a", "." @shell.should_receive(:file?).with("a").and_return false @shell.should_receive(:cp_r).with "aDir/templates/a.template/b", "." @shell.should_receive(:file?).with("b").and_return false @scaffolder.generate "a.template", 'myKata' end end

69. describe Scaffolder do it "replaces placeholders" do @shell.should_receive(:real_dir_entries).with("aDir/templates/a.template").and @shell.should_receive(:cp_r).with "aDir/templates/a.template/a",

    "." @shell.should_receive(:file?).with("a").and_return false @shell.should_receive(:cp_r).with "aDir/templates/a.template/README", "." @shell.should_receive(:file?).with("README").and_return true @shell.should_receive(:read_file).with("README").and_return '%rm% %kata_file%\ @shell.should_receive(:write_file).with "README", 'del myKata\nb.cmd\nc;d' @shell.should_receive(:cp_r).with "aDir/templates/a.template/run-once.sh", "." @shell.should_receive(:file?).with("run-once.sh").and_return true @shell.should_receive(:read_file).with("run-once.sh").and_return "%rm% a\nb.%s @shell.should_receive(:write_file).with "run-once.sh", "del a\nb.cmd\nc;d" @shell.should_receive(:cp_r).with "aDir/templates/a.template/run-endless.sh", @shell.should_receive(:file?).with("run-endless.sh").and_return true @shell.should_receive(:read_file).with("run-endless.sh").and_return "%rm% a\nb @shell.should_receive(:write_file).with "run-endless.sh", "del a\nb.cmd\nc;d" @scaffolder.generate "a.template", 'myKata' end end

70. describe Scaffolder do before(:each) do @shell = mock @shell.should_receive(:shell_extension).any_number_of_times.and_return "cmd"

    @shell.should_receive(:remove_command_name).any_number_of_times.and_return "de @shell.should_receive(:path_separator).any_number_of_times.and_return ";" @shell.should_receive(:dir_separator).any_number_of_times.and_return "/" Scaffolder.should_receive(:current_file).any_number_of_times.and_return("aDir/ @scaffolder = Scaffolder.new @shell end end

71. ZOM G ......F...

72. <3

73. test all the things

74. 30 assertions

75. 30 assertions @shell.should_receive(:x)

76. 30 assertions @shell.should_receive(:x) .with(y)

77. 30 assertions @shell.should_receive(:x) .with(y) .and_return z

78. ......... ......... ......... .........

79. unit tests 30 assertions 20 assertions 10 assertions 0 assertions

80. unit tests testing what, exactly?

81. @kata.generate README prime.rb run.sh ... ?

82. @kata.generate README prime.rb run.sh ...

83. magic happens here

84. @shell.should_receive(:real_dir_entries).with("aDir/ @shell.should_receive(:cp_r).with "aDir/templates/a. @shell.should_receive(:file?).with("a").and_return f @shell.should_receive(:cp_r).with "aDir/templates/a. @shell.should_receive(:file?).with("README").and_ret @shell.should_receive(:read_file).with("README").and @shell.should_receive(:write_file).with

    "README", 'd @shell.should_receive(:cp_r).with "aDir/templates/a. @shell.should_receive(:file?).with("run-once.sh").an @shell.should_receive(:read_file).with("run-once.sh" @shell.should_receive(:write_file).with "run-once.sh @shell.should_receive(:cp_r).with "aDir/templates/a. @shell.should_receive(:file?).with("run-endless.sh") @shell.should_receive(:read_file).with("run-endless. @shell.should_receive(:write_file).with "run-endless

85. delegation vs micro-management

86. unit tests have conceded defeat

87. describe Scaffolder do before (:each) do @shell = mock @shell.should_receive(:shell_extension).any_number_of_times.and_return

    "cmd" @shell.should_receive(:remove_command_name).any_number_of_times.and_return "del" @shell.should_receive(:path_separator).any_number_of_times.and_return ";" @shell.should_receive(:dir_separator).any_number_of_times.and_return "/" Scaffolder.should_receive(:current_file).any_number_of_times.and_return("aDir/lib/aFile.rb") @scaffolder = Scaffolder.new @shell end it "generates the files and directories" do @shell.should_receive(:real_dir_entries).with("aDir/templates/a.template").and_return ["a", "b"] @shell.should_receive(:cp_r).with "aDir/templates/a.template/a", "." @shell.should_receive(:file?).with("a").and_return false @shell.should_receive(:cp_r).with "aDir/templates/a.template/b", "." @shell.should_receive(:file?).with("b").and_return false @scaffolder.scaffold "a.template", 'myKata' end it "replaces placeholders" do @shell.should_receive(:real_dir_entries).with("aDir/templates/a.template").and_return ["a", "README", "run-once.sh", "run-endless.sh"] @shell.should_receive(:cp_r).with "aDir/templates/a.template/a", "." @shell.should_receive(:file?).with("a").and_return false @shell.should_receive(:cp_r).with "aDir/templates/a.template/README", "." @shell.should_receive(:file?).with("README").and_return true @shell.should_receive(:read_file).with("README").and_return '%rm% %kata_file%\nb.%sh%\nc%:%d' @shell.should_receive(:write_file).with "README", 'del myKata\nb.cmd\nc;d' @shell.should_receive(:cp_r).with "aDir/templates/a.template/run-once.sh", "." @shell.should_receive(:file?).with("run-once.sh").and_return true @shell.should_receive(:read_file).with("run-once.sh").and_return "%rm% a\nb.%sh%\nc%:%d" @shell.should_receive(:write_file).with "run-once.sh", "del a\nb.cmd\nc;d" @shell.should_receive(:cp_r).with "aDir/templates/a.template/run-endless.sh", "." @shell.should_receive(:file?).with("run-endless.sh").and_return true @shell.should_receive(:read_file).with("run-endless.sh").and_return "%rm% a\nb.%sh%\nc%:%d" @shell.should_receive(:write_file).with "run-endless.sh", "del a\nb.cmd\nc;d" @scaffolder.scaffold "a.template", 'myKata' end end

88. unit tests for the generated kata files

89. integration tests for the generated kata files

90. characterization

91. characterization run the code

92. characterization run the code make assertions about whatever happens

93. describe Scaffolder do end

94. describe Scaffolder do it "works" do scaffolder.generate('ruby.rspec', 'prime') end end

95. describe Scaffolder do let(:scaffolder) { } it "works" do scaffolder.generate('ruby.rspec',

    'prime') end end

96. describe Scaffolder do let(:scaffolder) { Scaffolder.new } it "works" do

    scaffolder.generate('ruby.rspec', 'prime') end end

97. describe Scaffolder do let(:scaffolder) { Scaffolder.new(shell) } it "works" do

    scaffolder.generate('ruby.rspec', 'prime') end end

98. describe Scaffolder do let(:shell) { ShellWrapper.new } let(:scaffolder) { Scaffolder.new(shell)

    } it "works" do scaffolder.scaffold('ruby.rspec', 'prime') end end
99. None

100. $ git status

101. $ git status # Untracked files: # #!.meta #!README #!prime.rb

     #!run-endless.sh #!run-once.sh

102. describe Scaffolder do let(:files) do [ '.meta', 'prime.rb', 'README', 'run-endless.sh',

     'run-once.sh' ] end it "works"... end

103. describe Scaffolder do it "works" do scaffolder.scaffold('ruby.rspec', 'prime') expect(File.read('.meta')).to eq('...')

     expect(File.read('README')).to eq('...') # etc end end

104. describe Scaffolder do after(:each) do files.each do |file| FileUtils.rm_f(file) end

     end it "works" do # ... end end

105. Finished in 0.00632 seconds 1 example, 0 failures .

106. I’m no genius and so can you

107. reality vs fantasy

108. red flag time to refactor

109. the secret fate of a characterization test

110. confidence to refactor

111. decouple template source and kata destination

112. simplify the algorithm

113. spot the abstractions

114. a KataFile KataFile = Struct.new(:name, :contents)

115. kata a Translator template

116. a KataStore ./templates/ruby.rspec/* [kata_file1, kata_file2, ...] [kata_file1, kata_file2, ...] /tmp/*

117. or something like that

118. theory vs practice

119. clarity and chaos

120. Query Command Incoming Private Outgoing assert return value assert side

     effects do not assert do not assert do not assert assert message sent

121. F F F F F F F thank you <3

     <3 <3 ......... c

122. Practical Object Oriented Design in Ruby Sandi Metz The Magic

     Tricks of Testing Sandi Metz Working Effectively with Legacy Code Michael Feathers CodersDojo Client FreeBSD License, (c) The CodersDojo Team Limited Red Joseph Wilk Fonts & Colors Damon Davison