Atlantec - tdd lessons
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This document discusses lessons and principles of test-driven development (TDD). It covers topics like writing tests before code, measuring complexity of code vs tests, using feedback from tests to drive development, and maintaining a co-evolving system through the TDD process of red-green-refactor cycles. Principles of systems thinking and feedback loops are also referenced in maintaining a stable system through controlled changes.
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Atlantec - tdd lessons
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- 26. 26 one or more tests failed
- 28. 28 syntax error
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- 32. 32 team
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- 37. 37 1 minute
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- 39. 39 diff
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- 42. 42 some data from a random sample of 500
- 43. 43 colour-to-colour diff deltas 3.94 5.39 4.67 4.65 7.52 6.01 17.67 average lines of code added+deleted 13.65 bigger delta == greater chance of amber
- 44. 44 bigger delta == greater chance of amber
- 45. 45 11 5 6 lots of amber runs
- 47. for example 45 minute exercise
- 48. code
- 49. test?
- 50. FizzBuzz 50
- 51. waterfail 45 minute exercise test 9 month project
- 52. waterfail test 8 months 1 month
- 53. waterfail test > 8 months < 1 month
- 54. waterfail
- 55. waterfail test test test test test test test test test test test test test test test tes tes tes
- 56. debugging!
- 58. 58 suppose you manage to remove what you don't want
- 59. 59 will you be left with what you do want?
- 60. 60 its like making toast by burning bread and then scraping the burn off!
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- 63. DDD TDD
- 65. 65 tests
- 67. 67 specific?
- 68. 68 !
- 69. 69 specific
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- 71. 71 suppose youve measured the complexity of your code and tests
- 73. 73 2.1 the average complexity of the code is
- 74. 74 by the way
- 75. 75 did you hear the one about the statistician who drowned crossing a river only six inches deep*
- 76. 76 did you hear the one about the statistician who drowned crossing a river only six inches deep* *average depth!
- 77. 77 3.7 the average complexity of the tests is
- 81. tests 2.0 2.1 code 81 < < is the less than operator
- 82. tests 1.6 2.1 code 82 << << is the much less than operator
- 83. tests 1.0 2.1 code 83 YES <<< <<< is the much much less than operator
- 85. 85 example
- 86. 86 example
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- 89. refactor write a test for new functionality implement the new functionality
- 90. refactor write a test for new functionality implement the new functionality
- 91. refactor write a test for new functionality implement the new functionality improve the diagnostic
- 93. refactor write a test for new functionality implement the new functionality improve the diagnostic coding testing
- 95. 95 why do cars have brakes?
- 96. 96 so you can drive faster
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- 98. 98 feedback test test test test test
- 99. 99 just calling it feedback doesnt mean it has actually fed back!
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- 102. 102 all change can be understood as the effort to maintain some constancy, and all constancy as maintained through change
- 103. 103 Henri Louis Le Chatelier systems tend to oppose their own proper function
- 104. 104 coding testing
- 105. 105 the battle is a means or process of generating, maintaining, and stabilising a system