clean code: four rules of simple design

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1 CLEAN CODE Four rules for simple design, according to Kent Beck

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WHO IS KENT BECK? 2 +Agile Manifesto +JUnit

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IS TDD DEAD? 3

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THE PURSUIT OF SIMPLICITY 4 Do the simplest thing that could possibly work

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5 RULE 1 - ALL TESTS MUST PASS ! Program correctness Feedback loops Conﬁdence levels Ease of evolution Working speciﬁcation ! !

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THE PYRAMID OF TESTING 6 Unit tests Integration tests Functional tests The higher we go ! ▫︎fewer numbers ▫︎slower feedback ▫︎higher cost

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7 ! ! Duplication is waste Eliminate waste Say it once, Say it well Less code means fewer bugs ! ! RULE 2 - ONCE AND ONLY ONCE (OOO)

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RULE 3 - EXPRESS YOUR INTENT 8 ! All in the name Staying small Role playing Tell, don’t ask The world as we see it

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9 ! ! ! Would you really need this? (minimal methods, classes, & modules) RULE 4 - NO SUPERFLUOUS PARTS

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FORM VS. FUNCTION 10

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ENDLESS POSSIBILITIES 11

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12 YOU AIN’T GONNA NEED IT! ! ! The world is changing. fast. Build for what you know. Over time, you’ll know more. What if I could look ahead?

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LISTEN TO THE CODE 13 ! ! 1. Write a test, make it pass, refactor 2. Refactor to the point of simplicity 3. Listen to the code

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THE SIMPLE DESIGN DYNAMO TM 14

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SUMMARY 15 ! ! 1. All tests must pass 2. Don’t repeat yourself 3. Express your intent 4. Stay lean

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For questions or suggestions: ! Avinash Chugh [email protected] THANK YOU

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REFERENCES 17 ! ! 1. http://c2.com/cgi/wiki?XpSimplicityRules 2. http://www.amazon.com/Clean-Code-Handbook-Software-Craftsmanship/dp/ 0132350882 3. http://math.ucr.edu/home/baez/physics/General/occam.html 4. http://blog.thecodewhisperer.com/2013/12/07/putting-an-age-old-battle-to-rest/