Rule to be used in tests that display a Toast with class name and method name when each test starting.

TestNameToastRule.kt

/**
 * Rule to be used in tests that display a Toast with class name and method name when each test starting.
 *
 * ```
 * @RunWith(AndroidJUnit4::class)
 * class FooTest {
 *
 *     @get:Rule
 *     val testNameToastRule = TestNameToastRule()
 *
 *     @Test
 *     fun testBar() {
 *         ....
 *     }
 * }
 * ```
 */
class TestNameToastRule : TestWatcher() {

    override fun starting(description: Description?) {
        super.starting(description)

        Handler(Looper.getMainLooper()).post {
            Toast.makeText(
                ApplicationProvider.getApplicationContext(),
                "${description?.testClass?.simpleName}.${description?.methodName}",
                Toast.LENGTH_LONG
            ).show()
        }
    }
}