Testing

Foundation aligns JVM unit tests with saveable’s JUnit 5 stack.

Rules of thumb

Source set	Framework	Notes
commonTest	kotlin.test	Multiplatform (JS / Wasm / Apple / Android)
jvmTest / androidHostTest	JUnit Jupiter (org.junit.jupiter)	Nested suites, extensions, params

Do not mix kotlin.test.Test with useJUnitPlatform() on JVM — Jupiter will not discover those methods. Assertions from kotlin.test remain fine as plain functions.

Monorepo wiring

criollo.kmp-library applies convention.junit5, which:

• Adds Jupiter + params to jvmTest / androidHostTest
• Adds junit-platform-launcher on the matching *RuntimeOnly configurations
• Sets every Test task to useJUnitPlatform()

Kotlin JVM modules (e.g. :testing, :project-conventions) apply convention.junit5 directly.

Nested layout

Group related cases with @Nested + inner class so IDE / CI reports stay readable:

class TaskScopeTest {

    @Nested
    inner class SkipIfActive {
        @Test
        fun skipIfActive_returnsSkipped() = runTest { /* … */ }
    }

    @Nested
    inner class ReplaceActive {
        @Test
        fun replaceActive_cancelsPrevious() = runTest { /* … */ }
    }
}

Shared helpers stay on the outer class and remain visible to nested suites.

Published helpers (testing)

Maven: io.github.jdbenitez94.criollo.kmp.foundation:testing

testImplementation(platform("io.github.jdbenitez94.criollo.kmp.foundation:bom:<version>"))
testImplementation("io.github.jdbenitez94.criollo.kmp.foundation:testing")

MainTestDispatcherExtension

Installs Dispatchers.Main with a TestDispatcher for each test method (ViewModel / UI code that calls Dispatchers.Main):

@MainTestDispatcher
class SignInViewModelTest {
    @Test
    fun loads() = runTest {
        // Dispatchers.Main is a test dispatcher
    }
}

Or register the extension as a field when you need the concrete dispatcher:

class SignInViewModelTest {
    @RegisterExtension
    @JvmField
    val main = MainTestDispatcherExtension()

    @Test
    fun loads() = runTest(main.dispatcher) { /* … */ }
}

Package: io.github.jdbenitez94.criollo.kmp.foundation.testing.