The `:core:testing` module is a dedicated **Kotlin Multiplatform (KMP)** library that provides shared test fakes, doubles, rules, and utilities. It is designed to be consumed by the `commonTest` source sets of all other KMP modules to ensure consistent and unified testing behavior across the codebase.
By centralizing fakes and mocking utilities here, we prevent duplication of test setups and enforce a standard approach to testing ViewModels, Repositories, and pure domain logic.
Some KMP modules interact with Android framework components (e.g., `android.net.Uri`, `androidx.room`, `DataStore`) that require Robolectric to run on the JVM. To maintain a unified test suite while providing platform-specific initialization, follow the **Subclassing Pattern**:
### 1. Create an Abstract Base Test in `commonTest`
Place your test logic in an abstract class in `src/commonTest`. Do NOT use `@BeforeTest` for setup that requires platform-specific context.
```kotlin
abstract class CommonMyViewModelTest {
protected lateinit var viewModel: MyViewModel
// Call this from subclasses
fun setupRepo() {
// ... common setup logic
}
@Test
fun testLogic() { /* ... */ }
}
```
### 2. Implement the JVM Subclass in `jvmTest`
A simple subclass is usually enough for pure JVM targets.
```kotlin
class MyViewModelTest : CommonMyViewModelTest() {
@BeforeTest
fun setup() {
setupRepo()
}
}
```
### 3. Implement the Android Subclass in `androidHostTest`
Use `@RunWith(RobolectricTestRunner::class)` and call `setupTestContext()` to initialize `ContextServices.app`.
```kotlin
@RunWith(RobolectricTestRunner::class)
@Config(sdk = [34])
class MyViewModelTest : CommonMyViewModelTest() {
@BeforeTest
fun setup() {
setupTestContext() // From :core:testing, initializes Robolectric context
- **Test Doubles / Fakes**: Provides in-memory implementations of core repositories (e.g., `FakeNodeRepository`, `FakeMeshLogRepository`) to isolate components under test.
- **Coroutines Testing**: Provides dispatchers and test rules that replace the main dispatcher with `TestDispatcher` to allow time-control and synchronous execution of coroutines in tests.
- **Mokkery Support**: Integrated with the Mokkery compiler plugin to provide robust and unified mocking capabilities in `commonTest`.
