Java Beginners Meetup February 2017: Testing and TDD
- 1. An introduction to testing and TDD Patrick Kostjens February 7, 2017 Java Beginners Meetup
- 2. Table of contents 1. Introduction 2. Test Driven Development 3. Unit testing in Java 4. Exercise 1 5. Exercise 2 1
- 3. Introduction
- 4. About me Patrick Kostjens Software Developer 2
- 5. Why testing? To build better software faster 3
- 6. Better software • Fewer bugs • Easier to maintain • Easier to change • Safer to change 4
- 7. How to test? Write code that checks if other code does what it is supposed to. 5
- 8. Types of testing 1. Unit testing 2. Integration testing 3. System testing 4. Acceptance testing 6
- 9. Testing concepts • Mocking • e2e • TDD • BDD 7
- 11. Brief introduction Writing tests to check if your code works seems good, right? 8
- 12. Brief introduction Writing tests to check if your code works seems good, right? But, maybe we are only testing what we expect to happen. 8
- 13. Brief introduction Writing tests to check if your code works seems good, right? But, maybe we are only testing what we expect to happen. What if we write our tests before we write (bits of) code? 8
- 14. Brief introduction Writing tests to check if your code works seems good, right? But, maybe we are only testing what we expect to happen. What if we write our tests before we write (bits of) code? Test Driven Development 8
- 15. TDD workflow 9
- 16. Why TDD? • No influence from knowledge gained while implementing 10
- 17. Why TDD? • No influence from knowledge gained while implementing • Immediately know if every bit of code works 10
- 18. Why TDD? • No influence from knowledge gained while implementing • Immediately know if every bit of code works • Keep code as simple as possible 10
- 19. Why TDD? • No influence from knowledge gained while implementing • Immediately know if every bit of code works • Keep code as simple as possible • Make code easy to test 10
- 20. Why TDD? • No influence from knowledge gained while implementing • Immediately know if every bit of code works • Keep code as simple as possible • Make code easy to test • Catch bugs early 10
- 21. Unit testing in Java
- 22. Tools and frameworks Frameworks: • JUnit • TestNG Tools: • Mockito • EasyMock • Powermock • Hamcrest 11
- 23. Simple test in JUnit import org.junit.Test; import org.junit.Assert; public class SimpleTest { @Test public void test1Returns1 () { Assert.assertEquals("1", getAnswer (1)); } } 12
- 24. Test preparation public class PrepareTest { private FizzBuzz testObject; @Before public void setup() { testObject = new FizzBuzz (); } @Test //... } 13
- 25. Exercise 1
- 26. Fizz Buzz project Take repository at: https://github.com/patrickkostjens/fizz-buzz-exercise Install and run using README 14
- 27. Fizz Buzz rules • Dividable by 3? Fizz • Dividable by 5? Buzz • Dividable by 3 and 5? Fizz Buzz • None of the above? Just a number Exercise Given a number, return the Fizz Buzz answer for that number. 15
- 28. Easy, right? Fizz Buzz seems to be very easy yet there are many solutions See: https://ditam.github.io/posts/fizzbuzz/ 16
- 29. Exercise 2
- 30. Bowling scoring system • No project setup available • Don’t build an interface • Start simple! • Try to do TDD 17
- 31. Thank you! 17