Testing Java with Groovy

Transcript

1. Testing with Java Groovy @tiagofernandez

2. “  One  size  fits  all.  ” #NOT

3. Tes2ng  is  hard.

4. TDD  makes  you  think.

5. Design Behavior Error_handling Dependencies Corner_cases

6. Java  adds  complexity!

7. Boilerplate  code   discourages  tes2ng.

8. Sta2c  typing  makes mocking  difficult.

9. Sta2c  &  final  methods   complicate  stubbing.

10. JUnit TestNG JBehave JMock JMockit EasyMock PowerMock Mockito PowerMockito JDave

11. None

12. Dynamic  language for  the  JVM Seamlessly  integrates  with  Java Almost-­‐zero

     learning  curve  for   Java  developers

13. Syntax  sugar

14. Groovy  has  na2ve  language   support  for  lists  &  maps.

15. def numbers = [4, 8, 15, 16, 23, 42] numbers

    << 99 def vowels = ['a', 'e', 'i', 'o', 'u'].asImmutable() vowels << 'x' // UnsupportedOperationException def colors = [ red: [255, 0, 0], green: [0, 255, 0], blue: [0, 0, 255] ]

16. Closures  allow  reusing   func2ons,  or  code  blocks.

17. def frameworks = ['Grails', 'Gaelyk', 'Griffon'] def languages = [

    Groovy: 'groovy.codehaus.org', Ruby: 'ruby-lang.org' ] frameworks.each { value -> println "Framework: $value" } languages.each { key, value -> println "$key's URL: http://$value/" }

18. def pets = ['cat', 'dog', 'fish', 'hamster', 'parrot'] def result1

    = pets.collect { it[0].toUpperCase() } assert result1 == ['C', 'D', 'F', 'H', 'P'] def result2 = pets.findAll { it.size() <= 3 } assert result2 == ['cat', 'dog'] def result3 = pets.grep(~/^f.*/) assert result3 == ['fish']

19. Templa2ng  is  easy  with   GString  &  builders.

20. class LetterTemplate { String from, to, message String getLetter() {

    """ ${new Date()} Dear $to, $message Best regards, $from """ } } def template = new LetterTemplate( from: 'Tiago', to: 'Cynthia', message: '...') println template.letter

21. import groovy.xml.MarkupBuilder new MarkupBuilder().html { head { title 'Programming Groovy,

    book by @venkat_s' } body { div(width: '100') { p(class: 'para') { span 'Best book to get started with Groovy!' span 'ISBN: 1934356093' } } } }

22. Dynamic  languages  lead  to elegant  and  concise  tests. Hint_#1

23. Groovier  tes2ng

24. JUnit  is  built  into  Groovy’s   run2me. junit.framework.TestCase GroovyTestCase

25. // More assertions class FooTest extends GroovyTestCase { void setUp()

    { ... } void tearDown() { ... } void test_should_do_something() { ... } } // No inheritance import org.junit.* class BarTest { @Before void setUp() { ... } @After void tearDown() { ... } @Test void should_do_something() { ... } }

26. def a = 10, b = 30 assert Math.max(a, b)

    == 20 Assertion failed: assert Math.max(a, b) == 20 | | | | 30 10 30 false

27. Groovy  provides  addi2onal   useful  asser2ons.

28. assertArrayEquals(Object[] expected, Object[] value) assertLength(int length, char[] array) assertLength(int length,

    int[] array) assertLength(int length, Object[] array) assertContains(char expected, char[] array) assertContains(int expected, int[] array) assertToString(Object value, String expected) assertInspect(Object value, String expected) assertScript(final String script) shouldFail(Closure code) shouldFail(Class clazz, Closure code)

29. class ArithmeticTest extends GroovyTestCase { void test_should_not_divide_by_zero() { shouldFail(ArithmeticException) {

    println 1/0 } } } class ArithmeticTest { final shouldFail = new GroovyTestCase().&shouldFail @Test void should_not_divide_by_zero() { shouldFail(ArithmeticException) { println 1/0 } } }

30. Simple  tests  means  more  2me   working  on  produc2on  code.

    Hint_#2

31. Mocks  &  stubs

32. Public  methods  can’t   always  modify  object  state.

33. 1. Reflec2on 2. Package-­‐scope Possible  workarounds  with  Java:

34. In  Groovy,  access  to  private fields  &  methods  is  free!

    Dirty_secret

35. // Production code (Java) public class SocialService { private final

    CassandraStorage storage; } public class CassandraStorage { private final Cluster cluster; } // Test code (Groovy) void tearDown() { def cluster = socialService.storage.cluster assert cluster.dropKeyspace('Social') != null }

36. Interfaces  can  be  faked  out   with  maps  &  closures.

37. def task = { println "Running..." } as Runnable new

    Thread(task).start() def messageSender = { from, to, message -> sentMessages << new Message(from, to, message) } as MessageSender def httpRequest = [ isUserInRole: { roleName -> roleName == "test_role“ } ] as HttpServletRequest

38. Available  to  Groovy  classes  only: ๏ Expandos ๏ Categories ๏

    StubFor  &  MockFor StringUtils.metaClass.static.lowerCase = { str -> str.toUpperCase() } // won’t work

39. Dynamic  features  facilitate   faking,  mocking  &  stubbing. Hint_#3

40. {  demo  }

41. developers  to  write encourages Less  ceremony more  tests.

42. developers  to  write encourages Expressive  code clean  tests.

43. developers  to  write encourages Fewer  constraints quality  tests.

44. Thanks Obrigado Merci Gracias Danke Bedankt Grazie ͋Γ͕ͱ͏ 谢谢 Dziękuję

    Спасибо Tack ا"#$

45. @TIAGOFERNANDEZ tiagofernandez.github.com