Zero-confidence by Katrina Owen

Watch the talk here: https://vimeo.com/68730418

Transcript

1. .................................
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   467 tests, 0 failures, 0 confidence
   Katrina Owen
   @kytrinyx
   JumpstartLab
   

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2. Pointe
   •◀
   .
   

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

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4. F F F F F F F F F
   

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5. test results
   not implementation
   

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6. results
   

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7. command query
   separation .
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   ✂
   

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8. returns a value, has no side effects
   query
   

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9. has side effects, returns nil
   command
   

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10. .
    .
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    .
    ✂
    command query
    

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11. query
    @waiter.menu
    

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12. command
    @bill.add(steak)
    

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13. both
    ... it’s complicated
    

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14. responsibility
    and collaboration
    

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15. mock
    expectation
    

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16. mock stub
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    ✂
    assertion dumb value
    

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17. who
    is responsible?
    

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18. sender
    :message
    receiver
    outgoing incoming
    

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19. incoming
    assert the state of the system
    

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20. outgoing
    assert collaboration
    

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21. rules
    of thumb
    

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22. Query
    Incoming ?
    

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23. Query
    Incoming assert return value
    

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24. Query Command
    Incoming assert return value ?
    

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25. Query Command
    Incoming assert return value assert side effects
    

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

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27. Query Command
    Incoming
    Outgoing
    assert return value assert side effects
    do not assert
    

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28. Query Command
    Incoming
    Outgoing
    assert return value assert side effects
    do not assert ?
    

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29. Query Command
    Incoming
    Outgoing
    assert return value assert side effects
    do not assert assert message sent
    

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30. Query Command
    Incoming
    Private
    Outgoing
    assert return value assert side effects
    ? ?
    do not assert assert message sent
    

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31. Query Command
    Incoming
    Private
    Outgoing
    assert return value assert side effects
    do not assert do not assert
    do not assert assert message sent
    

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32. Query Command
    Incoming
    Private
    Outgoing
    assert return value assert side effects
    do not assert do not assert
    do not assert assert message sent
    

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33. 1incoming query
    assert return value
    

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

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35. assert direct, local side effects
    2
    incoming command
    

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

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

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38. 3outgoing query
    do not assert
    

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39. 3outgoing query
    do not assert
    chef.todays_special
    

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40. assert message send
    4
    outgoing command
    

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

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

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

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

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45. 5private message
    do not assert
    

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

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47. unit test
    

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48. unit test
    return values +
    

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49. unit test
    return values +
    side effects +
    

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

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51. unit test
    return values +
    side effects +
    critical interations +
    implementation details -
    

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52. meet practice
    theory
    

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53. github.com/it-agile
    codersdojo_client
    

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

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55. code kata
    small coding exercise
    

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

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

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

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

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60. class Prime
    def foo
    'fixme'
    end
    end
    

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61. class Prime
    def foo
    'fixme'
    end
    end
    describe Prime do
    let(:prime) { Prime.new }
    its(:foo) { should == 'bar' }
    end
    

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63. limit
    work in progress
    

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64. Query Command
    Incoming
    Private
    Outgoing
    ✓
    

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65. incoming command
    assert direct, local side effects
    

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

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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
    

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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
    

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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
    

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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
    

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

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72. <3
    

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73. test
    all the things
    

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74. 30 assertions
    

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

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

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

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

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

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80. unit tests
    testing what, exactly?
    

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

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

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83. magic
    happens here
    

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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
    

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85. delegation
    vs micro-management
    

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86. unit tests
    have conceded defeat
    

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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
    

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88. unit tests
    for the generated kata files
    

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89. integration tests
    for the generated kata files
    

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90. characterization
    

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91. characterization
    run the code
    

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92. characterization
    run the code
    make assertions about
    whatever happens
    

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93. describe Scaffolder do
    end
    

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

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

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96. describe Scaffolder do
    let(:scaffolder) { Scaffolder.new }
    it "works" do
    scaffolder.generate('ruby.rspec', 'prime')
    end
    end
    

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97. describe Scaffolder do
    let(:scaffolder) { Scaffolder.new(shell) }
    it "works" do
    scaffolder.generate('ruby.rspec', 'prime')
    end
    end
    

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98. describe Scaffolder do
    let(:shell) { ShellWrapper.new }
    let(:scaffolder) { Scaffolder.new(shell) }
    it "works" do
    scaffolder.scaffold('ruby.rspec', 'prime')
    end
    end
    

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100. $ git status
     

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101. $ git status
     # Untracked files:
     #
     #!.meta
     #!README
     #!prime.rb
     #!run-endless.sh
     #!run-once.sh
     

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102. describe Scaffolder do
     let(:files) do
     [
     '.meta',
     'prime.rb',
     'README',
     'run-endless.sh',
     'run-once.sh'
     ]
     end
     it "works"...
     end
     

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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
     

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

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

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106. I’m no genius
     and so can you
     

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107. reality
     vs fantasy
     

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108. red flag
     time to refactor
     

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109. the secret fate
     of a characterization test
     

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110. confidence
     to refactor
     

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111. decouple
     template source and kata destination
     

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112. simplify
     the algorithm
     

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113. spot
     the abstractions
     

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

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115. kata
     a Translator
     template
     

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

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117. or something
     like that
     

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118. theory
     vs practice
     

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119. clarity
     and chaos
     

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120. Query Command
     Incoming
     Private
     Outgoing
     assert return value assert side effects
     do not assert do not assert
     do not assert assert message sent
     

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

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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
     

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