Curso De Testing Kotlin Fixed -

It’s time to change that. Welcome to your conceptual .

If you are reading this, you probably already love Kotlin for its conciseness and power. You use data classes , when expressions, and extension functions daily. But when it comes to testing that code, do you feel like you are still living in the past? Are you writing tests that look like Java 6?

Use backticks to write sentences as test names. Your test reports will read like documentation. Module 2: The Game Changer – Kotest If you take only one thing from this curso , let it be Kotest . It is the flagship testing framework for Kotlin, replacing JUnit with a radically different syntax. Why Kotest? It supports Spec styles (BehaviorSpec, StringSpec, FreeSpec) and Property Testing out of the box. Example: The Behavior Spec class UserServiceTest : BehaviorSpec({ val service = UserService() given("A user with a valid email") { val email = "test@example.com" `when`("I call register") { val result = service.register(email) then("It should return a success message") { result shouldBe "User created" } and("The user should be stored in the DB") { service.exists(email) shouldBe true } } } }) Assertions: shouldBe vs shouldNotBe Kotest replaces assertEquals with infix functions: curso de testing kotlin

import kotlinx.coroutines.test.runTest import kotlinx.coroutines.delay class ApiClientTest {

Whether you are building Android apps, backend services with Ktor or Spring Boot, or multi-platform libraries, Kotlin offers a unique set of tools to make testing not just bearable , but joyful . It’s time to change that

Kotest has the best property testing implementation on the JVM.

class MathProps : StringSpec({ "Addition should be commutative" { forAll { a: Int, b: Int -> // The property we want to test (a + b) == (b + a) } } "String length should be non-negative" { forAll<Int> { length -> val str = "x".repeat(length.coerceAtLeast(0)) str.length >= 0 } } }) You use data classes , when expressions, and

@Test fun `state flow emits new values`() = runTest { val viewModel = MyViewModel() val collector = viewModel.stateFlow.test { viewModel.doAction("Click") // Await the next emission val item = awaitItem() assertEquals("Loading", item.status) // Ensure no extra items came cancelAndIgnoreRemainingEvents() } } A professional Kotlin project separates test sources by type: