Unit Testing 101

Unit testing can save you time, money, and frustration by helping you create a safety net around your software to guarantee its stability and quality. This introductory session sets aside any testing methodologies such as Test or Behavioral Driven Development and instead focuses on the fundamentals of what unit tests are, how to write them, and some differences between the most popular unit test frameworks. You’ll also learn about organizing tests, creating test hierarchies, and heading off painful or brittle tests. We’ll also show you how to isolate dependencies using stubs, fakes, and mocks. You’ll leave this session with an understanding of how to get started writing unit tests.

Transcript

1. Unit Testing 101 Wednesday, October 12, 11
2. Jim Holmes @aJimHolmes Jim.Holmes@Telerik.com http:/ /blogs.telerik.com/ JimHolmes Wednesday, October 12, 11
3. Types of Automated Testing Wednesday, October 12, 11
4. Functional: Complete slice of functionality, generally at UI V E R Y S L O W Wednesday, October 12, 11
5. Integration: Testing across components or layers (web services, eg) Generally slow (ish) Wednesday, October 12, 11
6. Unit Testing: Small isolated portions of code. No dependencies -- VERY fast Wednesday, October 12, 11
7. Testing Methodologies Wednesday, October 12, 11
8. Test Occasionally Write tests (maybe) for easy stuff, or to cover a bug. Occasionally, like. Wednesday, October 12, 11
9. Test After Dev Write your system, then write some tests. Emphasis on “some” because it tends to get blown off... Wednesday, October 12, 11
10. Test Driven Development Write tests first, then write code to make tests pass Wednesday, October 12, 11
11. Behavior Driven Development Like TDD, but sounds cooler Wednesday, October 12, 11
12. OK, BDD seriously “TDD helps you write software correctly, BDD helps you write the correct software.” --Aslak Hellesoy Focuses on how system should behave -- interactions & outcomes, not just inputs/outputs Wednesday, October 12, 11
13. Why Test? Wednesday, October 12, 11
14. Prove you’ve fixed the bug Wednesday, October 12, 11
15. Tripwire against regressions Wednesday, October 12, 11
16. Prove your acceptance criteria are met Wednesday, October 12, 11
17. Lower risk Wednesday, October 12, 11
18. Automate testing so you can focus your brain on VALUE Wednesday, October 12, 11
19. It takes time.... Wednesday, October 12, 11
20. Cons of Testing Wednesday, October 12, 11
21. Design impacts Wednesday, October 12, 11
22. Brittle, bad tests are a time sink (and morale, too) Wednesday, October 12, 11
23. New skills needed ooooh, that’s scary Wednesday, October 12, 11
24. Pros of Testing Wednesday, October 12, 11
25. Safety net Wednesday, October 12, 11
26. Tests == Documentation (sort of) Wednesday, October 12, 11
27. Quality (Duh) Wednesday, October 12, 11
28. Flexibility & Speed I can change with confidence (or at least less fear) Wednesday, October 12, 11
29. What’s a Good Unit Test? Wednesday, October 12, 11
30. Granular Check one thing, and one thing only! (Mostly) Wednesday, October 12, 11
31. No Dependencies Dependencies external to the test get mocked <Insert_Monty_Python_Joke_Here/> Wednesday, October 12, 11
32. Readable Tests are system knowledge. Make sure they’re understandable! Wednesday, October 12, 11
33. FAST! Slow unit tests indicate mixed concerns, too much responsibility, dependencies Wednesday, October 12, 11
34. CORRECT! Bad tests kill kittens Wednesday, October 12, 11
35. ENOUGH TALK! LET’S CODE! Wednesday, October 12, 11
36. The Tools Test Frameworks MbUnit (Gallieo) www.Gallieo.org Nunit www.NUnit.org Mocking Frameworks Rhino Mocks http://is.gd/bCCk9 Moq http://is.gd/bCCim NMock http://nmock.org Telerik’s JustMock http://is.gd/bCCbq Wednesday, October 12, 11
37. Books Roy Osherove's Art of Unit Testing Bob Martin's Agile Patterns & Principles in C# Hunt & Thomas's Pragmatic Unit Testing (C#/.NET) Wednesday, October 12, 11
38. Jim Holmes @aJimHolmes Jim.Holmes@Telerik.com http:/ /blogs.telerik.com/ JimHolmes Wednesday, October 12, 11