Understanding bdd and tdd with lego
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This document discusses Behavior Driven Development (BDD) and Test Driven Development (TDD). It provides an overview of these concepts and how they work together. BDD focuses on having conversations to ensure the right software is being built, while TDD focuses on writing tests first to ensure the software is built correctly. The document uses LEGO exercises to demonstrate TDD principles like the red-green-refactor process in a hands on way.
Understanding bdd and tdd with lego
- 1. Understanding BDD & TDD with LEGO Kev McCabe @bigmadkev ! Adapted from: Bryan Beecham @BillyGarnet Mike Bowler @mike_bowler http://bigmadkev.com/resources
- 2. http://bigmadkev.com/resources House Keeping! ▪ Please have your phones out ! ▪ Please talk and have side conversations ! ▪ Please Tweet, Facebook, Blog, Rave about todays sessions! – only if their good ones Have Fun!!!!!!
- 3. http://bigmadkev.com/resources BDD & TDD ▪ BDD = Behavior Driven Development ! ▪ TDD = Test Driven Development
- 4. http://bigmadkev.com/resources BDD & TDD ▪ They solve separate problems ! ▪ They work together ! ▪ TDD – Build the thing right ▪ Low level fast tests ! ▪ BDD – Build the right thing ▪ Conversations & Examples
- 5. http://bigmadkev.com/resources Thanks to Nat Pryce and Steve Freeman for im5 age
- 6. http://bigmadkev.com/resources Thanks to Nat Pryce and Steve Freeman for im6 age
- 7. http://bigmadkev.com/resources BDD ▪ Three Amigos ▪ Tester ▪ Developer ▪ Stakeholder ! ! !
- 8. http://bigmadkev.com/resources BDD User stories & acceptance criteria Domain Learning Examples ExEaxmampplelses ExEaxmampplelses New Stories Open Questions
- 9. http://bigmadkev.com/resources Having Conversations ! Is more important than capturing conversations ! Is more important than automating conversations www.slideshare.net/lunivore/behavior-‐driven-‐development-‐11754474 Liz Keogh @lunivore
- 10. http://bigmadkev.com/resources BDD IS NOT ABOUT THE TOOLS! ! IT’S ABOUT THE CONVERSATIONS
- 11. http://bigmadkev.com/resources Agile Stories As a <role>, I want to <do something> so that <I get some value>.
- 12. http://bigmadkev.com/resources Value Agile Stories In order to <get some value> <role> should be able to <do something>
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- 15. https://speakerdeck.com/jbrains/the-‐next-‐decade-‐of-‐agile-‐software-‐development The Next Decade (of Agile Software Development) by J. B. Rainsberger
- 16. https://speakerdeck.com/jbrains/the-‐next-‐decade-‐of-‐agile-‐software-‐development The Next Decade (of Agile Software Development) by J. B. Rainsberger
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- 18. http://bigmadkev.com/resources Exercise -‐ 1 ▪ Open up one LEGO packet each ! ▪ Build a person and a house out of LEGO
- 19. http://bigmadkev.com/resources Admire your work ▪ Take a photo. Upload to Twitter. Brag to your friends
- 20. Reference
- 21. http://bigmadkev.com/resources What is the goal of TDD? ▪ It creates clean code that works ~ Ron Jefferies
- 22. http://bigmadkev.com/resources TDD ▪ It is a predictable way to develop. You know when you are finished, without having to worry about a long bug trail.
- 23. http://bigmadkev.com/resources TDD ▪ It gives you a chance to learn all of the lessons that the code has to teach you. If you only slap together the first thing you think of, then you never have time to think of a second, better thing.
- 24. http://bigmadkev.com/resources TDD ▪ It improves the lives of the users of your software.
- 25. http://bigmadkev.com/resources TDD ▪ It lets your teammates count on you, and you on them.
- 26. http://bigmadkev.com/resources TDD ▪ It feels good to write it.
- 27. The Mantra Red -‐ Green -‐ Refactor photo from doolwind.com
- 28. http://bigmadkev.com/resources The Mantra – Red ▪Write a small test that shows the code doesn’t work
- 29. http://bigmadkev.com/resources The Mantra – Green ▪ Do the minimum to make the code work
- 30. http://bigmadkev.com/resources The Mantra -‐ Refactor ▪ Eliminate duplication ! ▪ Ensure code clarity ! ▪ Is it the simplest it could be?
- 31. http://bigmadkev.com/resources You won’t stay agile without clean code ! You can’t have clean code without refactoring ! You can’t refactor without good automated tests
- 32. http://bigmadkev.com/resources Exercise -‐ 2 ▪ Build a person and a house with TDD
- 33. http://bigmadkev.com/resources Prepare your environment ▪ Clear the area in front of you. ! ▪ This is your program. ! ▪ The perfect program!
- 34. http://bigmadkev.com/resources First Test ▪ Does the person exist? ! ▪ No?
- 35. Hurray!!! We failed the test! Celebrate! High 5s!
- 36. http://bigmadkev.com/resources Minimum to pass the test ▪ Add a block. Can that be a person?
- 37. http://bigmadkev.com/resources Hurray!!! ▪ The person now exists! ! ▪ Not very impressive but it could represent a person. ! ▪ We passed the test! We are rocking now!
- 38. http://bigmadkev.com/resources Refactor ▪ Remove any duplication. In this case we’re good.
- 39. http://bigmadkev.com/resources Same thing for house ▪ Is there a house?
- 40. http://bigmadkev.com/resources Same thing for house ▪ You know what to do now right?
- 41. http://bigmadkev.com/resources We need a new test ▪ The house is taller then the person. ! ▪ Assert.IsTrue(house.height > person.height);
- 42. Hurray!!! -‐ More Failure The person is the same size so we fail this test. Well done!
- 43. Failure = Learning Opportunity ▪ If you’re not failing, you’re not learning. ! ▪ If you’re not learning...
- 44. http://bigmadkev.com/resources Minimum to pass the test ▪ From the audience this time. ! ▪ Anyone?
- 45. http://bigmadkev.com/resources Hurray!!! -‐ Success ▪ Alright, we passed the test.
- 46. http://bigmadkev.com/resources Refactor ▪ Still very simple. Still nice and clean.
- 47. http://bigmadkev.com/resources Software Requirements ▪ Software must do three things: ▪ It must work ▪ It must be understandable ▪ It must be updatable
- 48. http://bigmadkev.com/resources We need a new test ▪ Is the house wider then the person? No? ! ▪ We failed another test! Awesome! We are learning a lot about improvements that are needed to our code. ! ▪ Let’s do the minimum to pass the test. ! ▪ Any duplication to remove?
- 49. Exercise -‐ 3 Partners! ▪ Break into groups of two for this next exercise. ! ▪ When developers do this we call it Pair Programming ! ▪ Berkley photo from the web
- 50. http://bigmadkev.com/resources Lego Sim Town In order to have a town to run The Mayor requires A small town comprised of: ! A family A house A tree An animal A vehicle
- 51. http://bigmadkev.com/resources We need a new test ▪ Work together and write down a new test ▪ Build minimally pass the test ▪ Repeat (Don’t worry about Refactoring for now) ▪ Here’s a few if you get stuck: ▪ Is the house at least x bricks tall? ▪ Is the tree the same size as the house? ▪ Is the animal smaller than the person?
- 52. Exercise 3 – Lego Sim Town ▪A family ▪A house ▪A tree ▪An animal ▪A vehicle ▪ Is the house at least x bricks tall? ! ▪ Is the tree the same size as the house? ! ▪ Is the animal smaller than the person?
- 54. http://bigmadkev.com/resources Review ▪ Test-‐Driven Development / Design ▪ Refactoring ▪ Pair Programming ▪ A bit of developer speak ▪ Experience working on a software team
- 56. http://bigmadkev.com/resources Four Elements of Simple Design ▪ Passes its tests ! ▪ Minimizes duplication ! ▪ Maximizes clarity ! ▪ Has fewer elements
- 57. http://bigmadkev.com/resources Closing Circle ▪ What did you learn today? ! ▪ What surprised you today? ! ▪ What will you do differently in the future?