Using Kotlin for tests

Android Testing Boot Camp
TwitterID変えました。@lvla0805 -> @MoyuruAizawa

Transcript

1. Using Kotlin for tests @lvla0805
2. lvla lvla0805 Ѫᖒ
   ๖ (Moyuru Aizawa) - Kotlin engineer of FRESH! Div. CyberAgent, Inc. - Previously at Pairs Div. Eureka, Inc.
3. JetBrains/Kotlin v1.1.2 junit-team/junit4 v4.12 mockito/mockito v2.7.22 ntaro/knit v0.1.2 sys1yagi/kmockito v0.1.2 Note As of April 27
4. Kotlin?
5. ‣ JetBrains, OSS ‣ Statically typed programming language ‣ For the JVM, Android and the browser ‣ Interoperable with Java Kotlin?
6. ‣ Type inference ‣ Null safety ‣ Property ‣ Functional programming support ‣ Extension functions ‣ Delegation ‣ … Features
7. Set Up
8. Preferences -> Plugin -> Install JetBrains plugin… -> Search “Kotlin” -> Install Set Up
9. Tools -> Kotlin -> Configure Kotlin in Project Set Up
10. dependencies { compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version" } Set Up
11. dependencies { compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version" testCompile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version" } Set Up
12. Unit Test
13. Assertion
14. public class Person { public final String firstName; public final String familyName; public Person(String firstName, String familyName) { this.firstName = firstName; this.familyName = familyName; } public String getFullName() { return firstName + " " + familyName; } } Person
15. public class Person { public final String firstName; public final String familyName; public Person(String firstName, String familyName) { this.firstName = firstName; this.familyName = familyName; } public String getFullName() { return firstName + " " + familyName; } } Person
16. class PersonTest { @Test fun getFullName() { val person = Person("Moyuru", "Aizawa") assertThat(person.fullName, `is`("Moyuru Aizawa")) } } Test Person#getFullName
17. class PersonTest { @Test fun getFullName() { val person = Person("Moyuru", "Aizawa") assertThat(person.fullName, `is`("Moyuru Aizawa")) } } Test Person#getFullName Create a instance of “Person”
18. class PersonTest { @Test fun getFullName() { val person = Person("Moyuru", "Aizawa") assertThat(person.fullName, `is`("Moyuru Aizawa")) } } Test Person#getFullName
19. class PersonTest { @Test fun getFullName() { val person = Person("Moyuru", "Aizawa") assertThat(person.fullName, `is`("Moyuru Aizawa")) } } Test Person#getFullName Property
20. class PersonTest { @Test fun getFullName() { val person = Person("Moyuru", "Aizawa") assertThat(person.fullName, `is`("Moyuru Aizawa")) } } Test Person#getFullName “is” is reserved word of Kotlin
21. Mock
22. public class Person { ... @Override public boolean equals(Object o) { ... } @Override public int hashCode() { ... } } Person#equals, Person#hashCode
23. public class PersonDao { public void insert(List<Person> persons) { ... } } PersonDao
24. public class PersonClient { public Single<List<Person>> fetch() { ... } } PersonClient
25. public class PersonRepository { private final PersonDao dao; private final PersonClient client; ... public Single<List<Person>> getPersons() { return client.fetch() .doOnSuccess(dao::insert); } } Test PersonRepository#getPersons
26. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock(PersonDao::class.java) val client = mock(PersonClient::class.java) val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() `when`(client.fetch()).thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) verify(dao).insert(expected) } } Test PersonRepository#getPersons
27. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock(PersonDao::class.java) val client = mock(PersonClient::class.java) val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() `when`(client.fetch()).thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) verify(dao).insert(expected) } } Test PersonRepository#getPersons Mock classes
28. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock(PersonDao::class.java) val client = mock(PersonClient::class.java) val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() `when`(client.fetch()).thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) verify(dao).insert(expected) } } Test PersonRepository#getPersons
29. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock(PersonDao::class.java) val client = mock(PersonClient::class.java) val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() `when`(client.fetch()).thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) verify(dao).insert(expected) } } Test PersonRepository#getPersons Create expected values [Person(firstName=0, familyName=0), Person(firstName=1, familyName=1), …]
30. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock(PersonDao::class.java) val client = mock(PersonClient::class.java) val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() `when`(client.fetch()).thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) verify(dao).insert(expected) } } Test PersonRepository#getPersons Configure return behavior for mock
31. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock(PersonDao::class.java) val client = mock(PersonClient::class.java) val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() `when`(client.fetch()).thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) verify(dao).insert(expected) } } Test PersonRepository#getPersons Configure return behavior for mock
32. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock(PersonDao::class.java) val client = mock(PersonClient::class.java) val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() `when`(client.fetch()).thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) verify(dao).insert(expected) } } Test PersonRepository#getPersons Configure return behavior for mock
33. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock(PersonDao::class.java) val client = mock(PersonClient::class.java) val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() `when`(client.fetch()).thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) verify(dao).insert(expected) } } Test PersonRepository#getPersons “when” is reserved word of Kotlin
34. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock(PersonDao::class.java) val client = mock(PersonClient::class.java) val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() `when`(client.fetch()).thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) verify(dao).insert(expected) } } Test PersonRepository#getPersons Invoke PersonRepository#getPersons and assertion
35. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock(PersonDao::class.java) val client = mock(PersonClient::class.java) val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() `when`(client.fetch()).thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) verify(dao).insert(expected) } } Test PersonRepository#getPersons Verify invocation
36. Write more simple codes
37. ‣ knit ‣ Junit API set for Kotlin ‣ kmockito ‣ Mockito for Kotlin Libraries for Kotlin tests
38. knit
39. class PersonTest { @Test fun getFullName() { val person = Person("Moyuru", "Aizawa") assertThat(person.fullName, `is`("Moyuru Aizawa")) } } [BEFORE] Test Person#getFullName
40. class PersonTest { @Test fun getFullName() { val person = Person("Moyuru", “Aizawa") person.fullName.should be "Moyuru Aizawa" } } [AFTER] Test Person#getFullName
41. class PersonTest { @Test fun getFullName() { val person = Person("Moyuru", “Aizawa") person.fullName.should be "Moyuru Aizawa" } } How does it work?
42. class PersonTest { @Test fun getFullName() { val person = Person("Moyuru", “Aizawa") person.fullName.should be "Moyuru Aizawa" } } How does it work? Extension property
43. class PersonTest { @Test fun getFullName() { val person = Person("Moyuru", “Aizawa") person.fullName.should be "Moyuru Aizawa" } } How does it work? Infix call
44. kmockito
45. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock(PersonDao::class.java) val client = mock(PersonClient::class.java) val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() `when`(client.fetch()).thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) verify(dao).insert(expected) } } [BEFORE] Test PersonRepository#getPersons
46. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock<PersonDao>() val client = mock<PersonClient>() val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() client.fetch().invoked.thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) dao.verify().insert(expected) } } [AFTER] Test PersonRepository#getPersons
47. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock<PersonDao>() val client = mock<PersonClient>() val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() client.fetch().invoked.thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) dao.verify().insert(expected) } } How does it work?
48. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock<PersonDao>() val client = mock<PersonClient>() val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() client.fetch().invoked.thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) dao.verify().insert(expected) } } How does it work? Inline function, reified type parameter
49. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock<PersonDao>() val client = mock<PersonClient>() val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() client.fetch().invoked.thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) dao.verify().insert(expected) } } How does it work? Extension property
50. class PersonRepositoryTest { @Test fun getPersons() { val dao = mock<PersonDao>() val client = mock<PersonClient>() val repository = PersonRepository(dao, client) val expected = Array(5, Int::toString) .map { Person(it, it) }.toList() client.fetch().invoked.thenReturn(Single.just(expected)) repository.getPersons().test().assertValue(expected) dao.verify().insert(expected) } } How does it work? Extension function
51. TIPS
52. Data class
53. public class Person { public final String firstName; public final String familyName; public Person(String firstName, String familyName) { this.firstName = firstName; this.familyName = familyName; } public String getFullName() { return firstName + " " + familyName; } @Override public boolean equals(Object o) { … } @Override public int hashCode() { … } } It is too annoying to override equals/hashCode
54. data class Person(val firstName: String, val lastName: String) { fun getFullName() = firstName + " " + lastName } Use data class The compiler automatically derives equals()/hashCode(), toString(), …
55. Mock Kotlin classes
56. ‣ By default, all classes in Kotlin are final ‣ Mockito cannot mock final classes… Mock Kotlin classes
57. ‣ Open ‣ Interface ‣ PowerMock ‣ Mockito 2.1.0(or above) MockMaker (*experimental) How to mock…?
58. open class PersonClient { open fun fetch(): Single<List<Person>> { ... } } Open
59. @AllOpen class PersonClient { fun fetch(): Single<List<Person>> { ... } } All Open (Kotlin compiler plugin)
60. interface PersonClient { fun fetch(): Single<List<Person>> } class PersonClientImpl: PersonClient { override fun fetch(): Single<List<Person>> { ... } } Interface
61. val client = PowerMock.mock(PersonClient::class.java) `when`(client.fetch()).thenReturn(Single.just(expected)) PowerMock
62. Create the file src/test/resources/mockito-extensions/org.mockito.plugins.MockMaker containing a single line mock-maker-inline or testCompile “org.mockito:mockito-core:2.x.y” testCompile “org.mockito:mockito-inline:2.x.y" Mockito2 MockMaker
63. ‣ Create the file src/test/resources/mockito-extensions/org.mockito.plugins.MockMaker ‣ Configure resolutionStrategy configurations { test { resolutionStrategy { force “org.mockito:mockito-core:2.x.y” // 2.1.0 or above } } } Use inline mock maker with kmockito
65. Thank you