Code Quality Assurance. Peter Kofler, Code Cop FH Technikum Wien, February 2010

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1 Code Quality Assurance Peter Kofler, Code Cop FH Technikum Wien, February 2010

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3 Peter Kofler Ph.D. (Appl. Math.) Professional Software Developer for 11 years Lead Developer at System One fanatic about code quality 3

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5 Zero-Defect Mindset (MSF) 5

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9 Robert C. Martin ( Uncle Bob ) 9

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11 Software Craftsmanship 11

12 Craftsmanship Over Crap 12

13 The Prime Factors Kata 13

14 The Requirements. Write a class named PrimeFactors that has one static method: generate. The generate method takes an integer argument and returns a List<Integer>. That list contains the prime factors in numerical sequence. 14

15 Demo 15

16 Keep the bar green to keep the code clean 16

17 Unit Testing test individual units isolate each part show that the individual parts are correct regression testing sort of living documentation executed within a framework 17

18 xunit Frameworks e.g. Smalltalk - SUnit Java - JUnit, TestNG.NET - NUnit, Typemock C++ - CppUTest Groovy, PHP, Python, Ruby, Scala, etc. 18

19 TESTING I FIND YOUR LACK OF TESTS DISTURBING. 19

20 Test-Driven Development add a test run all tests and see if the new one fails write some code run all tests and see them succeed refactor code Red Green Refactor 20

21 The Three Laws of TDD You are not allowed to write any production code unless to make a failing unit test pass. You are not allowed to write any more of a unit test than is sufficient to fail; and compilation failures are failures. You are not allowed to write any more production code than is sufficient to pass the one failing unit test. 21

22 A minute ago all their code worked! 22

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25 Testing is a mindset. 25

26 You have to want it. 26

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28 Code Coverage comprehensiveness of tests 28

29 Beware! comprehensiveness quality! 29

30 Some Code Coverage Tools Java - EMMA, Cobertura, Clover.NET - NCover, PartCover C++ - Covtool, gcov Ruby - rcov commercial products 30

31 Demo 31

32 Demo 32

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34 Daily/Nightly Builds 34

35 Continuous Integration 35

36 Continuous Integration Maintain a code repository Automate the build Make the build self-testing Everyone commits every day Every commit should be built Keep the build fast Everyone can see the results of the build 36

37 Immediate Feedback & Early Warning 37

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39 Some CI Servers Java - CruiseControl, Hudson.NET - CruiseControl.NET, Hudson (NAnt) C++ - Hudson (Shell/Make) Ruby - CruiseControl.rb commercial products - TeamCity, ALA 39

40 Book Continuous Integration (Paul Duvall) 40

41 Good Enough? 41

42 Demo 42

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44 Check What? Lexical analysis naming, coding conventions, design idioms Flow/path analysis null-pointer, dead code (conditional) Dependency analysis architectural/design flaws Verification mathematical proof of correctness 44

45 Some Static Analysis Tools Java - Checkstyle, Findbugs, PMD.NET - FxCop, (ReSharper, NDepend) C++ - (Sp)Lint Ruby - Roodi, Dust, Flog, Saikuro commercial products 45

46 Good Enough? 46

47 Demo 47

48 Some Code Review Tools Your peer (Pair Programming) Your version control system Your IDE (e.g. ReviewClipse) commercial products 48

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50 Thank You 50

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52 Links #1 Mindset (Zero-Defect Mindset) oup%20presentation_frame.htm (Zero-Defect Mindset) Test

53 Links #2 Test Code Coverage Continuous Integration

54 Links #3 Continuous Integration Static Code Analysis Code Review

55 Images spray face: broken egg: windows: red-green: Darth Vader: Model covered car: works: Agnes: microscope: code review: questions: 55