JUnit rules and test parameterization

Slides for my talk about JUnit rules and test parameterization at Coders on Beers. The content is Portuguese.

Transcript

1. JUnit rules e parametrização: tenha orgulho do seus testes de novo Matheus C. Candido Android @ Concrete
2. Agenda • Rules • Parametrização • Aplicações reais
3. Rules
4. Rules • Componente do JUnit 4 que serve para interceptar testes • Casos de uso comum incluem: orquestração de tarefas, preparação de recursos temporários (pastas, servidores, etc) • Evitam as famosas classes BaseTest
5. ExternalResource • Uma base class para quando é necessário configurar algum recurso antes da execução de cada teste e desligá-lo logo após • Dois métodos helper: before() e after()
6. ExternalResource class ServerRule : ExternalResource() { val server = Server() override fun before() { server.connect() } override fun after() { server.disconnect() } }
7. ExternalResource class ServerRule : ExternalResource() { val server = Server() override fun before() { server.connect() } override fun after() { server.disconnect() } }
8. ExternalResource class ServerRule : ExternalResource() { val server = Server() override fun before() { server.connect() } override fun after() { server.disconnect() } }
9. ExternalResource class ApiTest : ExternalResource() { @get:Rule private val serverRule = ServerRule() private val api = Api() @Test fun shouldDisplay404PageForPath() { serverRule.server.mockPath("/hello", 404) assertEquals("not found", api.sendHello()) } }
10. ExternalResource class ApiTest : ExternalResource() { @get:Rule private val serverRule = ServerRule() private val api = Api() @Test fun shouldDisplay404PageForPath() { serverRule.server.mockPath("/hello", 404) assertEquals("not found", api.sendHello()) } }
11. ExternalResource class ApiTest : ExternalResource() { @get:Rule private val serverRule = ServerRule() private val api = Api() @Test fun shouldDisplay404PageForPath() { serverRule.server.mockPath("/hello", 404) assertEquals("not found", api.sendHello()) } }
12. RuleChain • Possibilita a execução de rules de forma encadeada (em ordem) • Útil quando é preciso combinar rules em novas, evitando acoplamento, aumentando o código reutilizável
13. Parametrização
14. Parametrização de testes https://github.com/junit-team/junit4/wiki/parameterized-tests [0,0] [1,1] [2,1] [3,2] [4,3] [5,5] [6,8] @RunWith(Parameterized::class) class FibonacciTest( val input: Int, val expected: Int ) { companion object { @JvmStatic @Parameterized.Parameters fun data() = // input data } @Test fun assertNFibonacci() { assertEquals( expected, Fibonacci.compute(input) ) } } Input
15. Parametrização de testes https://github.com/junit-team/junit4/wiki/parameterized-tests [0,0] [1,1] [2,1] [3,2] [4,3] [5,5] [6,8] @RunWith(Parameterized::class) class FibonacciTest( val input: Int, val expected: Int ) { companion object { @JvmStatic @Parameterized.Parameters fun data() = // input data } @Test fun assertNFibonacci() { assertEquals( expected, Fibonacci.compute(input) ) } } Input
16. Parametrização de testes https://github.com/junit-team/junit4/wiki/parameterized-tests [0,0] [1,1] [2,1] [3,2] [4,3] [5,5] [6,8] @RunWith(Parameterized::class) class FibonacciTest( val input: Int, val expected: Int ) { companion object { @JvmStatic @Parameterized.Parameters fun data() = // input data } @Test fun assertNFibonacci() { assertEquals( expected, Fibonacci.compute(input) ) } } Input
17. Parametrização de testes https://github.com/junit-team/junit4/wiki/parameterized-tests [0,0] [1,1] [2,1] [3,2] [4,3] [5,5] [6,8] @RunWith(Parameterized::class) class FibonacciTest( val input: Int, val expected: Int ) { companion object { @JvmStatic @Parameterized.Parameters fun data() = // input data } @Test fun assertNFibonacci() { assertEquals( expected, Fibonacci.compute(input) ) } } Input
18. Burst A unit testing library for varying test data. • Implementação melhorada da parametrização do JUnit • Não é necessário campos estáticos na hora de prover os dados de entrada • Desenvolvida pela Square • Usa Enums em vez de Object https://github.com/square/burst
19. Contexto Aplicações
20. Boilerplate de frameworks class StartAndCloseKoinRule( private val app: Application, private val modules: List<Module>, private val baseUrl: String ) : ExternalResource() { override fun before() { startKoin( modules, extraProperties = mapOf(PROPERTY_BASE_URL to baseUrl) ) with app } override fun after() { closeKoin() } }
21. Boilerplate de frameworks class StartAndCloseKoinRule( private val app: Application, private val modules: List<Module>, private val baseUrl: String ) : ExternalResource() { override fun before() { startKoin( modules, extraProperties = mapOf(PROPERTY_BASE_URL to baseUrl) ) with app } override fun after() { closeKoin() } }
22. Boilerplate de frameworks class StartAndCloseKoinRule( private val app: Application, private val modules: List<Module>, private val baseUrl: String ) : ExternalResource() { override fun before() { startKoin( modules, extraProperties = mapOf(PROPERTY_BASE_URL to baseUrl) ) with app } override fun after() { closeKoin() } }
23. Integrando rules comuns class ActivityRule<T : Activity> ( activityClass: Class<T>, initialTouchMode: Boolean = true, launchActivity: Boolean = true ) : TestRule, KoinComponent { val activityRule = ... val requestMatcherRule = ... val koinRule = ... private val delegateRule = RuleChain .outerRule(requestMatcherRule) .around(koinRule) .around(activityRule) override fun apply( base: Statement, description: Description ) = delegateRule.apply(base, description) }
24. Integrando rules comuns class ActivityRule<T : Activity> ( activityClass: Class<T>, initialTouchMode: Boolean = true, launchActivity: Boolean = true ) : TestRule, KoinComponent { val activityRule = ... val requestMatcherRule = ... val koinRule = ... private val delegateRule = RuleChain .outerRule(requestMatcherRule) .around(koinRule) .around(activityRule) override fun apply( base: Statement, description: Description ) = delegateRule.apply(base, description) }
25. Integrando rules comuns class ActivityRule<T : Activity> ( activityClass: Class<T>, initialTouchMode: Boolean = true, launchActivity: Boolean = true ) : TestRule, KoinComponent { val activityRule = ... val requestMatcherRule = ... val koinRule = ... private val delegateRule = RuleChain .outerRule(requestMatcherRule) .around(koinRule) .around(activityRule) override fun apply( base: Statement, description: Description ) = delegateRule.apply(base, description) }
26. Parametrizando temas class StartAndCloseKoinRule( private val app: Application, private val modules: List<Module>, private val baseUrl: String ) : ExternalResource() { override fun before() { startKoin( modules, extraProperties = mapOf(PROPERTY_BASE_URL to baseUrl) ) with app } override fun after() { closeKoin() } }
27. Parametrizando temas class StartAndCloseKoinRule( private val app: Application, private val modules: List<Module>, private val baseUrl: String, private val theme: Int ) : ExternalResource() { override fun before() { startKoin( modules, extraProperties = mapOf(PROPERTY_BASE_URL to baseUrl) ) with app val appConfig = get<AppConfig>() appConfig.theme = theme } override fun after() { closeKoin() } }
28. Parametrizando temas class DashboardActivity : AppCompatActivity() { private val appConfig by inject<AppConfig>() override fun onCreate(savedInstanceState: Bundle?) { setTheme(appConfig.theme) super.onCreate(savedInstanceState) // ... } }
29. Parametrizando temas class DashboardActivity : AppCompatActivity() { private val appConfig by inject<AppConfig>() override fun onCreate(savedInstanceState: Bundle?) { setTheme(appConfig.theme) super.onCreate(savedInstanceState) // ... } }
30. Parametrizando temas class DashboardActivity : AppCompatActivity() { private val appConfig by inject<AppConfig>() override fun onCreate(savedInstanceState: Bundle?) { setTheme(appConfig.theme) super.onCreate(savedInstanceState) // ... } } class DashboardActivityTest { @get:Rule val activityRule = ActivityRule(DashboardActivity::class.java) @Test fun dashboardIsBeingDisplayedCorrectly() { activityRule.snapActivity() } }
31. screenshot-tests-for-android
32. Shot
33. Parametrizando temas class DashboardActivity : AppCompatActivity() { private val appConfig by inject<AppConfig>() override fun onCreate(savedInstanceState: Bundle?) { setTheme(appConfig.theme) super.onCreate(savedInstanceState) // ... } } @RunWith(BurstJUnit4::class) class DashboardActivityTest { @get:Rule val activityRule = ActivityRule(DashboardActivity::class.java) @Test fun dashboardIsBeingDisplayedCorrectly() { activityRule.snapActivity() } }
34. Parametrizando temas class DashboardActivity : AppCompatActivity() { private val appConfig by inject<AppConfig>() override fun onCreate(savedInstanceState: Bundle?) { setTheme(appConfig.theme) super.onCreate(savedInstanceState) // ... } } @RunWith(BurstJUnit4::class) class DashboardActivityTest { @get:Rule val activityRule = ActivityRule(DashboardActivity::class.java) @Test fun dashboardIsBeingDisplayedCorrectly() { activityRule.snapActivity() } }
35. Parametrizando temas class ActivityRule<T : Activity> ( activityClass: Class<T>, initialTouchMode: Boolean = true, launchActivity: Boolean = true ) : TestRule, KoinComponent { // ... fun snapActivity(name: String? = null) { val prefixName = getScreenshotPrefix() val fullName = name?.let { "${prefixName}_$it" } ?: prefixName Screenshot.snapActivity(activity).setName(fullName).record() } private fun getScreenshotPrefix(): String { val testClass = TestNameDetector.getTestClass() val testName = TestNameDetector.getTestName() return "$testClass.$testName.${themeName}" } }
36. Parametrizando temas class ActivityRule<T : Activity> ( activityClass: Class<T>, initialTouchMode: Boolean = true, launchActivity: Boolean = true ) : TestRule, KoinComponent { // ... fun snapActivity(name: String? = null) { val prefixName = getScreenshotPrefix() val fullName = name?.let { "${prefixName}_$it" } ?: prefixName Screenshot.snapActivity(activity).setName(fullName).record() } private fun getScreenshotPrefix(): String { val testClass = TestNameDetector.getTestClass() val testName = TestNameDetector.getTestName() return "$testClass.$testName.${themeName}" } }
37. Parametrizando temas class ActivityRule<T : Activity> ( activityClass: Class<T>, initialTouchMode: Boolean = true, launchActivity: Boolean = true ) : TestRule, KoinComponent { // ... fun snapActivity(name: String? = null) { val prefixName = getScreenshotPrefix() val fullName = name?.let { "${prefixName}_$it" } ?: prefixName Screenshot.snapActivity(activity).setName(fullName).record() } private fun getScreenshotPrefix(): String { val testClass = TestNameDetector.getTestClass() val testName = TestNameDetector.getTestName() return "$testClass.$testName.${themeName}" } }
38. Parametrizando temas enum class Theme { THEME_A, THEME_B } @RunWith(BurstJUnit4::class) class DashboardActivityTest(theme: Theme) { @get:Rule val activityRule = ActivityRule( DashboardActivity::class.java, overrideTheme = theme ) @Test fun dashboardIsBeingDisplayedCorrectly() { activityRule.snapActivity() } }
39. Parametrizando temas enum class Theme { THEME_A, THEME_B } @RunWith(BurstJUnit4::class) class DashboardActivityTest(theme: Theme) { @get:Rule val activityRule = ActivityRule( DashboardActivity::class.java, overrideTheme = theme ) @Test fun dashboardIsBeingDisplayedCorrectly() { activityRule.snapActivity() } }
40. Filtrando parâmetros enum class Theme { THEME_A, THEME_B } @RunTestsFor([Theme.THEME_A]) @RunWith(BurstJUnit4::class) class DashboardActivityTest(theme: Theme) { @get:Rule val activityRule = ActivityRule( DashboardActivity::class.java, overrideTheme = theme ) @Test fun dashboardIsBeingDisplayedCorrectly() { activityRule.snapActivity() } }
41. Filtrando parâmetros @Target(AnnotationTarget.CLASS) @Retention(AnnotationRetention.RUNTIME) annotation class RunTestsFor( val themes: Array<Theme> )
42. Filtrando parâmetros class ScreenshotFilterRule( private val testClass: Class<*>, private val themeBeingTested: Theme ) : TestRule { override fun apply(base: Statement, description: Description) = IgnoreStatement(base, testClass, themeBeingTested) class IgnoreStatement( private val baseStatement: Statement, private val clazz: Class<*>, private val themeBeingTested: Theme ) : Statement() { override fun evaluate() { val message = "Test ignored" val annotation = clazz.getAnnotation(RunTestsFor::class.java) val ignore = annotation != null && !annotation.themes.contains(themeBeingTested) assumeFalse(message, ignore) baseStatement.evaluate() } } }
43. Filtrando parâmetros class ScreenshotFilterRule( private val testClass: Class<*>, private val themeBeingTested: Theme ) : TestRule { override fun apply(base: Statement, description: Description) = IgnoreStatement(base, testClass, themeBeingTested) class IgnoreStatement( private val baseStatement: Statement, private val clazz: Class<*>, private val themeBeingTested: Theme ) : Statement() { override fun evaluate() { val message = "Test ignored" val annotation = clazz.getAnnotation(RunTestsFor::class.java) val ignore = annotation != null && !annotation.themes.contains(themeBeingTested) assumeFalse(message, ignore) baseStatement.evaluate() } } }
44. Filtrando parâmetros class ScreenshotFilterRule( private val testClass: Class<*>, private val themeBeingTested: Theme ) : TestRule { override fun apply(base: Statement, description: Description) = IgnoreStatement(base, testClass, themeBeingTested) class IgnoreStatement( private val baseStatement: Statement, private val clazz: Class<*>, private val themeBeingTested: Theme ) : Statement() { override fun evaluate() { val message = "Test ignored" val annotation = clazz.getAnnotation(RunTestsFor::class.java) val ignore = annotation != null && !annotation.themes.contains(themeBeingTested) assumeFalse(message, ignore) baseStatement.evaluate() } } }
45. Filtrando parâmetros class ScreenshotFilterRule( private val testClass: Class<*>, private val themeBeingTested: Theme ) : TestRule { override fun apply(base: Statement, description: Description) = IgnoreStatement(base, testClass, themeBeingTested) class IgnoreStatement( private val baseStatement: Statement, private val clazz: Class<*>, private val themeBeingTested: Theme ) : Statement() { override fun evaluate() { val message = "Test ignored" val annotation = clazz.getAnnotation(RunTestsFor::class.java) val ignore = annotation != null && !annotation.themes.contains(themeBeingTested) assumeFalse(message, ignore) baseStatement.evaluate() } } }
46. Filtrando parâmetros enum class Theme { THEME_A, THEME_B } @RunTestsFor([Theme.THEME_A]) @RunWith(BurstJUnit4::class) class DashboardActivityTest(theme: Theme) { @get:Rule val activityRule = ActivityRule( DashboardActivity::class.java, overrideTheme = theme ) @get:Rule val screenShotFilter = ScreenshotFilterRule(javaClass, theme) @Test fun dashboardIsBeingDisplayedCorrectly() { activityRule.snapActivity() } }
47. Filtrando parâmetros enum class Theme { THEME_A, THEME_B } @RunTestsFor([Theme.THEME_A]) @RunWith(BurstJUnit4::class) class DashboardActivityTest(theme: Theme) { @get:Rule val activityRule = ActivityRule( DashboardActivity::class.java, overrideTheme = theme ) @get:Rule val screenShotFilter = ScreenshotFilterRule(javaClass, theme) @Test fun dashboardIsBeingDisplayedCorrectly() { activityRule.snapActivity() } }
48. Resumo • Nova ActivityRule com mais funcionalidades (setup de DI, mock web server) sem usar uma classe base • Execução de testes com diferentes parâmetros (temas) e filtros
49. Obrigado!